AIDS Treatment Data Network

Descriptions of opportunistic infections and conditions
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A

AIDS:

The late stage of a disease caused by infection with the virus called HIV. There is a difference between being HIV-positive (HIV+) and having AIDS.

acupuncture:

Therapy in which needles are applied to meridians (set points of the body). The precise disorder treated or the degree of anesthesia required determines the temperature of the needle used, the angle of insertion, the speed of insertion and withdrawal.

acute:

Rapid in onset; severe, life-threatening. The opposite of persistent, chronic, or long-term.

adjuvant:

Any substance which enhances the immune-stimulating properties of an antigen or the pharmacological effect of a drug.

administration:

This term refers to how a drug is taken.

adverse reaction (side effect):

Participants in clinical trials may have reactions to the experimental medicines. Toxic reactions are usually listed in the protocol and the participant's Informed Consent. However, some reactions may never have been reported before. Any amount of toxicity must be reported within 24 hours by telephone to the sponsor of the trial, who then must tell the FDA. A clinical trial can be stopped because of an adverse reaction. Approved drugs can also have side effects. All side effects that may be caused by an approved drug are listed on the labeling.

aerosolized:

A form of administration in which a drug, such as pentamidine, is turned into a fine spray or mist by a nebulizer. The drug is then inhaled.

aggregation:

Collecting of units or parts into a mass or whole.

AIDS Clinical Testing Unit (ACTU):

The sites where NIAID's AIDS drug clinical trials are performed.

AIDS Clinical Trials Group (ACTG):

The federal AIDS drug testing organization.

alkaline phosphatase (alk phos):

Cell enzyme. Measurements in blood help with diagnosis of many illnesses. High levels are found in bone diseases, bone regeneration, liver obstruction and hepatitis. An enzyme measurement that indicates the health of the liver.

allergy:

An immediate or delayed immune reaction caused by a substance such as dust, a drug, or other foreign material that causes an allergic reaction amebiasis: Infection caused by a tiny animal parasite which lives in the human large intestine.

ALT (alanine aminotransferase):

Enzyme found in blood and body tissues, especially in the liver. ALT levels are greatly increased in cases of liver disease or infectious mononucleosis.

Amplicor:

See polymerase chain reaction test.

amylase:

A class of enzymes (proteins). Amylase it is secreted by salivary glands and the pancreas to aid digestion of food. An increase in amylase levels may indicate pancreatitis.

anabolic steroid:

Naturally occurring hormones that help convert protein into muscle. Testosterone is an anabolic steroid. May be useful in treating wasting associated with AIDS.

analgesic:

Agent that reduces pain without reducing consciousness. Aspirin is an analgesic.

analog (analogue):

A chemical compound with a structure similar to that of another but differing from it in respect to a certain component; it may have a similar or opposite action metabolically.

anaphylaxis:

General term to describe a serious allergic reaction to a toxin, drug or foreign substance the immune system was unable to recognize.

anemia:

A condition which occurs if the blood cannot carry enough oxygen to nourish tissues. Common symptoms of anemia are fatigue, headache, and shortness of breath. Anemia may be caused by too few red blood cells or too little hemoglobin or both.

angiogenisis:

Formation of new blood vessels. The way KS lesions are formed.

ano-genital intraepithelial neoplasia:

Cancer of the skin cells of the anal or genital region.

anorexia:

Prolonged loss of appetite that leads to significant weight loss.

antagonist:

A drug that prevents or reverses the action of another drug.

antibacterial:

A substance which stops or checks the growth of bacteria.

antibodies:

Proteins in the blood which recognize and block foreign substances.

anticoagulant:

A substance that delays or counteracts blood clotting.

antifungal:

A substance which kills or inhibits the growth of a fungus.

antigen:

A substance which, when introduced into the body, is capable of starting the production of a specific antibody by the immune system.

anti-inflammatory:

A substance which counteracts or suppresses inflammation. Swelling and redness are types of inflammation. There are two types of anti- inflammatory drugs: steroids, such as cortisone, and non-steroidal agents, such as aspirin.

antineoplastic:

Stopping or slowing the growth and spread of neoplasms or malignant cells in cancer.

antioxidant:

Substances that may prevent free radicals from causing damage. Molecules in the body that are oxidized can cause cell damage. Examples of antioxidants are vitamins A, C and E.

antiretroviral:

A substance that stops or suppresses the activity of a retrovirus such as HIV. AZT, ddC, ddI, d4T, 3TC, saquinavir, ritonavir, indinavir nevirapine, etc. are examples of antiretroviral drugs.

antiviral:

A type of substance or process which destroys a virus or suppresses its pathogenic action.

ARC (AIDS Related Complex):

HIV positive with symptoms. Usually called HIV disease.

aspergillosis:

A disease caused by a fungus. It can cause lesions of the skin, ear, orbit, nasal sinuses, lungs and sometimes the bones, meninges, heart, kidneys or spleen. Symptoms include fever, chills, difficulty breathing, and coughing up blood. If the infection reaches the brain, it may cause dementia.

aspirate:

Withdraw fluid, such as blood, from the body using suction. Sometimes done with a needle.

assay:

A test.

assessments:

The act of determining the importance, size, or value of something or someone.

AST (aspartate aminotransferase):

Enzyme that helps get rid of excess nitrogen in the liver. Released into the blood in tissue damage. AST levels are part of blood work.

asymptomatic:

Infection without symptoms. Someone who is asymptomatic has antibodies to HIV but does not have any visible signs or symptoms of HIV infection.

ataxia:

Loss of muscle control leading to jerky or uncoordinated movements.

atresia:

Absence or closure of a natural passage in the body. Can be heart valves, lung arteries, or liver damage.

atrophy:

A wasting or decrease in size.

attenuated virus:

A weakened virus whose ability to infect or produce disease is potentially reduced.

autoantibodies:

Antibodies that mistakenly attack host cells.

autoimmune disease:

A disease which arises from and is directed against an individual's own tissues.

B

bDNA:

See branched DNA assay.

B-lymphocytes (B-cells):

One of the immune system cell types; B cells fight infection primarily by making antibodies. During infections, these cells are transformed into factories that make thousands of antibodies against a foreign substance. This transformation occurs through interactions with various types of T-cells and other components of the immune system.

B symptoms:

Fever, night sweats, weight loss.

bacteria:

A group of microscopic organisms that cause disease when they infect someone.

basal cell carcinoma:

An epithelial (skin) cancer that seldom spreads but can destroy tissue.

baseline:

The first or starting measurement. New measurements of blood values are compared to this starting value.

bDNA: See branched DNA assay.

bilateral:

Two-sided, or affecting equally two sides.

bilateral peripheral neuropathy:

Stinging, numbness or other nerve pain caused by damage to the nerves in the peripheral nervous system. The peripheral nervous system includes nerves that run from the brain and spinal cord to the rest of the body. Many of these nerves are involved with sensation and feeling things such as pain, temperature and touch. Bilateral means both sides of the body.

bilirubin:

A reddish yellow pigment occurring in bile, blood, urine and gallstones.

bioavailability:

The rate and extent to which a substance is absorbed and circulated in the body.

biopsy:

Removal and laboratory examination of tissue from the living body. In some cases a tiny piece of skin is cut off and examined. Other types of biopsy can be more serious, such as a brain biopsy, which is done very rarely. A biopsy is usually done to clearly determine the cause of an illness.

blastomycosis:

An infectious disease caused by a fungus, usually in the lungs. It can spread to the skin, bone or other tissues.

blood brain barrier:

A barrier between brain blood vessels and brain tissues. This barrier controls what goes into the brain. Some drugs cannot cross this barrier, making brain infections difficult to treat.

bone marrow:

Soft tissue inside most bones.

bone marrow suppression:

A condition that can be caused by certain drugs. It leads to a decrease in white blood cells, red blood cells, and platelets. This can lead to bleeding or infections. People taking medications known to cause bone marrow suppression should have frequent blood tests.

branched DNA assay (bDNA):

One of several new tests that measure the amount of HIV in the blood (commonly known as viral load). The test uses a light-detecting system to find HIV RNA particles in a blood sample. The intensity of light generated by the captured particles is proportional to the amount of HIV present.

bronchoscopy:

Insertion of a thin flexible tube into the lungs through the nose or mouth. Often used as a diagnostic tool for PCP.

buffered:

Coated with a special substance which allows easier absorption by the stomach. Buffered drugs often prevent stomach upset. They may also help to avoid damage by stomach acids.

Burkitt's lymphoma:

A malignant cancer of the lymphatic system. Epstein-Barr virus has been isolated from Burkitt's lymphoma and is suspected as a causative agent.

C

cachexia:

General ill health and malnutrition. A general weight loss and wasting occurring in the course of a chronic disease or emotional disturbance.

cancer:

A large group of diseases characterized by uncontrolled growth and spread of abnormal cells.

candidiasis:

A fungal infection, often seen as white patches in the mouth called thrush. Can cause vaginal candidiasis and disease in other parts of the body.

cardiac arrhythmia:

Change in rhythm of the heartbeat either in time or force.

cardiac dysfunction:

Impaired or abnormal functioning of the heart.

cardiomyopathy:

Enlargement and obstructive damage to the heart.

catheter:

A device that allows drugs to be given on an ongoing basis. A catheter is put in the chest during a minor operation.

CD4 (T4):

A protein embedded in the outside of immune system cells called helper T-lymphocytes, or T cells. The protein allows scientists to identify helper T cells, also called T4 cells. The protein is also used by HIV to infect these cells. The number of T4 cells in a blood sample is used to measure the health of the immune system in people with HIV.

CD8 (T8):

A protein embedded in the cell surface of certain T-lymphocytes. CD8 T-lymphocytes (also called T8 cells) include suppressor cells and cytotoxic T-lymphocytes (CTLs).

CDC:

The Centers for Disease Control and Prevention. A federal health agency that is a branch of the Public Health Service.

cell:

The smallest independent unit of an organism. A cell is composed of cytoplasm and a nucleus, and is surrounded by a membrane or wall.

central nervous system (CNS):

The brain and spinal cord with their nerves and end organs that control voluntary acts.

cervical dysplasia:

Abnormal tissue development of the lower part of the uterus; may progress to cancer of the uterus.

chemokines:

A family of proteins produced by white blood cells that act as chemical messengers between cells. Examples of chemokines are RANTES, MIP-1 aplha and MIP-1 beta.

chemotherapeutic:

The treatment or control of disease or mental illness. Often refers to cancer treatments.

chemotherapy:

The use of chemical agents in the treatment of a disease.

CHF:

Abbreviation for congestive heart failure.

chlamydia:

A bacterial infection that can cause disease. Left untreated it can lead to cancer.

chronic:

Continuous or ongoing.

CMV colitis:

Inflammation of the colon that is associated with CMV(cytomegalovirus).

CMV-end organ disease:

CMV is a viral infection that can happen anywhere in the body. When it infects vital organs such as the liver, kidney or lungs, the infection is called end organ disease.

CMV retinitis:

A herpes infection in the eye which can cause blindness. It is common in people with AIDS. People with CMV retinitis must take treatment for the rest of their life.

CNS (central nervous system):

The main part of the nervous system including the brain and spinal cord.

CNS metastases:

When a disease of the central nervous system moves from one organ or part to another not directly connected with it.

coagulation:

Thickening.

coagulation factors:

Substances in the blood essential to clotting and normal stoppage of bleeding.

co-factor:

Something that may also affect a disease. Hemophiliacs who have both herpes and HIV progress to AIDS faster than do hemophiliacs who do not have herpes. The herpes is said to be a co-factor in the progression to AIDS.

cognitive impairment:

Problems with memory and thinking. Can be caused by HIV. Sometimes used to describe a less severe form of dementia.

colitis:

Inflammation of the colon, part of the intestines.

combination therapy:

The use of two or more drugs as treatment. Also, the use of two or more types of treatment in combination, alternately or together.

comparison trial:

A trial in which experimental drugs are tested against each other or against an approved drug.

compassionate use IND:

People who are seriously ill can have their doctor ask the drug company to give them an experimental drug they think will help them. Few drugs are available through this program, but they are usually free.

complete blood count (CBC):

Series of tests including cell counts, hematocrit, hemoglobin, and cell volume measurement.

congenital:

Existing at or dating from birth, not through heredity.

congestive:

Excessive fullness of the blood vessels.

congestive heart failure:

When the heart is unable to maintain adequate circulation of blood or the unable to pump out the blood returned to it by the veins.

continuous infusion:

Uninterrupted introduction of fluid other than blood into a vein.

controlled trials:

Trials in which one group gets the experimental drug and another group gets either a placebo or an approved drug therapy. Participants usually do not know which group they are in.

CPCRA:

Community Programs for Clinical Research on AIDS. Part of the NIH's Division of AIDS.

creatinine:

A protein found in muscles and blood and excreted by the kidneys in the urine. The level of creatinine in the blood and urine provides a measure of kidney function.

crossover:

A controlled drug trial in which, halfway through the study, the groups in the trial switch. That is, those taking the experimental drug are given the standard drug and vice versa.

cryptococcal meningitis:

A fungal infection of the brain and spinal cord. Symptoms include severe headache, dizziness, nausea, weight loss, vision disorders and mental deterioration. Meningitis with headache, blurred vision, confusion, dizziness, nausea, anorexia, depression, agitation or slurred speech are common symptoms.

cryptosporidiosis:

An infection whose main symptom is prolonged diarrhea which leads to weight loss. All treatments for this illness are still experimental.

culture:

A growth of microorganisms or other living cells.

cyclospora:

an intestinal parasite that can cause severe diarrhea in people with AIDS. A recent outbreak was associated with contaminated North American strawberries.

cytokines:

Proteins produced by white blood cells that act as chemical messengers between cells. Examples of cytokines are tumor necrosis factor (TNF), alpha-interferon, and interleukin-2.

cytomegalovirus:

A virus related to the herpes family, CMV infections may occur without any symptoms or may result in mild flu-like symptoms of aching, fever, mild sore throat, weakness or enlarged lymph nodes. In AIDS, severe CMV infections can cause illnesses such as hepatitis, pneumonia, retinitis and colitis, leading in some cases to blindness, chronic diarrhea, and death.

cytotoxic:

Term used to describe something which damages cells. Also used as the name of a type of T-cell.

cytotoxic T lymphocyte (CTL):

A lymphocyte that is able to kill foreign cells that have been marked for destruction by the immune system.

D

dementia:

Loss of memory and other intellectual functioning caused by HIV or another disease.

diabetes:

General term referring to disorders characterized by excessive urine excretion. Many different forms of diabetes exist such as adult-onset(non-insulin dependent) or diabetes mellitus which is insulin dependent.

diaphragmatic hernia:

A hernia is the protrusion of a loop or piece of an organ or tissue through an abnormal opening. Diaphragmatic herniation refers to the abdominal walls pushing into the thorax which is the part of the body between the neck and the respiratory diaphragm, enclosed by the ribs and chest.

diastolic:

Dilation or period of dilatation of the heart when the heart fills with blood in between the second and first heart sound.

dose:

The amount of a drug that is given at one time. dose comparison:

A trial that uses different amounts of the same drug. Sometimes the drug is tested against a placebo.

dose escalation trial:

In this type of trial, one or a few people, usually under a dozen, take a small amount of the drug. If it doesn't hurt them, one or a few more take a larger amount. This continues until the researchers find the largest amount of the drug that can be taken without immediate harm.

dose ranging:

A drug trial in which two or more doses of a given drug are being tested against each other in order to determine which dose works best and is the least harmful.

double-blind:

A type of drug trial in which people are divided into different groups. One group takes the experimental drug and other groups take different doses, the standard therapy, or placebo. Neither the researchers nor the person in the trial knows who is taking what until the trial is over.

E

EBV (Epstein-Barr virus):

A herpesvirus that causes infectious mononucleosis and is associated with lymphoma and throat and nose cancer.

echinocandin:

Related to the spine.

eczema:

Inflammatory skin condition. Symptoms include redness, itching, and oozing lesions which become scaly, crusted, or hardened.

encephalitis:

Inflammation of the brain. Symptoms include headache, neck pain, fever, nausea, and vomiting. Nervous system problems may occur such as laziness, paralysis, weakness, and coma. Treatment includes antibiotics for infection, steroids to reduce brain swelling, medicine to control fever and headache, and prolonged bedrest. Several types of opportunistic infections can cause encephalitis.

enzyme:

Protein chemical that can accelerate a chemical reaction in the body.

eosinophil:

A type of white blood cell, called a granulocyte, that can digest microorganisms.

Epstein-Barr virus (EBV):

A herpes-like virus that causes one of the two kinds of mononucleosis (the other is caused by CMV).

erythrocytes:

Red blood cells whose primary function is to carry oxygen to cells.

esophageal:

Related to the esophagus, the passage going from the pharynx (deep throat) to the stomach.

esophagoscopy:

Examination of the esophagus. The esophagus is the passage going from the throat to the stomach. A tube is put down the throat.

expanded access:

Programs designed to make experimental drugs available on a wide basis to people who do not qualify for the drug trials or who live too far from a trial site.

experimental drug:

A drug that has not been approved for use as a treatment for a particular condition.

F

fasting triglycerides:

A triglyceride is a fat made from carbohydrates for storage in fat cells. When broken down it releases fatty acids into the blood. Amount of triglycerides can be affected by drugs and tests can measure amount in blood.

floaters:

Floating dark spots within the field of vision. They can be caused by CMV retinitis, but also appear in some persons as a normal part of the aging process. An HIV-knowledgeable eye doctor can make a correct diagnosis.

fungus:

A general term used to denote a class of microbes including mushrooms, yeast, and molds. Fungi cause infections such as thrush, cryptococcal meningitis, and toxoplasmosis.

G

gamma globulin (IgG):

The portion of the plasma that contains antibodies.

gastroenteritis:

Inflammation of the lining of the stomach and intestines.

gamma globulins:

A type of immunoglobulin (see below) made by plasma cells, which is able to resist infection by viruses and bacteria. Simple proteins found in blood serums which contain various molecules central to immune system function.

gastroschisis:

Narrow opening of the abdominal wall usually the small and part of the large intestine sticking out. A birth defect.

gastrointestinal:

Of or about the stomach and the intestines

genital herpes:

Herpes simplex primarily transmitted sexually via genital secretions and/or contact with the virus involving the genitals. Herpes simplex is any inflammatory skin disease caused by a herpesvirus with the formation of clusters of small vesicles.

genotypic:

The entire genetic constitution of an individual.

gp120:

gp120: A piece of HIV that can cause damage to the immune system and other parts of the body. gp120 is the foundation for several vaccines.

granulocytes:

A cell type of the immune system filled with granules of toxic chemicals that enable them to digest microorganisms. Basophils, neutrophils, and eosonophils, are examples of granulocytes.

granulocytopenia:

An abnormally low number of granulocytes in the circulating blood that can lead to increased risk of severe bacterial infection.

growth factors:

A growth factor is responsible for regulating cell proliferation (rapid and repeated reproduction), function and differentiation. Different growth factors elicit different responses from different cell types, such as stimulating cell growth, enhancing cell survival, initiating cell migration and stimulating the secretion of tissue-specific hormones.

G6PD deficiency:

Enzyme that helps change sugar into energy. Affects over 100 million people with hemolytic anemia. A birth defect.

H

hairy leukoplakia:

A whitish, slightly raised lesion that appears on the side of the cheeks, gums or tongue. Thought to be related to Epstein-Barr Virus infection. (OI)

half-life:

The time required for half the amount of a drug to be gotten rid of by the body.

helper cell (T4 cells, CD4 cells):

A subset of T cells that carry the T4 marker and are essential for turning on antibody production, activating cytotoxic T cells, and initiating other immune responses. The number of T4 cells in a blood sample is used to measure the health of the immune system in people with HIV.

hematocrit:

The percentage of packed red blood cells in a given volume of blood. Normal ranges:

women 37-43%, men 43-49%.

hemoglobin:

The protein in red-blood cells responsible for carrying oxygen.

hemophilia:

An inherited disease that prevents the normal clotting of blood.

hepatic:

About the liver

hepatitis B (HBV):

A viral liver disease that can be acute or chronic and even life- threatening, particularly in people with poor immune resistance.

hepatotoxic:

Damaging to the liver.

herpes simplex virus I (HSV I):

A virus which causes cold sores or fever blisters on the mouth or around the eyes and can be transmitted to the genital region. The latent virus can be reactivated by stress, trauma, other infections or suppression of the immune system.

herpes simplex virus II (HSV II):

A virus causing painful sores of the anus or genitals which may lie dormant in nerve tissue and can be reactivated to produce the symptoms. HSV II may be transmitted to a baby during birth.

herpes zoster: Herpes zoster, also called shingles, consists of very painful blisters on the skin that follow nerve pathways.

Hgb (hemoglobin):

The oxygen-carrying pigment of the red blood cells, formed by the developing red blood cells in bone marrow.

Hickman catheter:

A flexible, needle shaped tube which can be surgically placed in a large blood vessel and held in place for a long periods of time.

histamine:

A hormone/chemical transmitter involved in local immune responses, in regulating stomach acid production and in allergic reactions.

histoplasmosis:

A fungal infection that causes acute pneumonia, inflammation of the meninges, heart, peritoneum, adrenals, and all other organs of the body. Symptoms usually include fever, shortness of breath, cough, weight loss and physical exhaustion.

HIV disease:

A term used to describe a variety of symptoms and signs found in people who are HIV positive. These may include recurrent fevers, unexplained weight loss, swollen lymph nodes, and/or fungus infection of the mouth and throat. Also commonly described as symptomatic HIV infection.

Hodgkin's disease:

A progressive malignant cancer of the lymphatic system. Symptoms include lymphadenopathy, wasting, weakness, fever, itching, night sweats and anemia. This disease is treated with radiation and chemotherapy; newer combinations of anticancer drugs are being tried constantly with increasing success.

hormone:

A substance made by the body to influence a process. Testosterone, for example, is a hormone that makes people more aggressive and muscular. Most men have more of this hormone than women.

hyperbilirubinemia:

Too much bilirubin in the blood which may lead to jaundice(yellowing of the skin and eyes). Bilirubin is a product of red blood cells when they die. Too much indicates liver problems.

hypersensitivity:

A situation in which the body reacts with an exaggerated immune response to drugs or other substances.

hypertension:

Abnormally high blood pressure, especially the pressure of moving oxygenated blood away from the heart.

hypertrophy:

Enlargement of an organ or part, an increase in bulk such as thickening of muscle fibers.

I

idiosyncratic:

Peculiar to any individual.

IDU:

An injection or intravenous drug user (IVDU).

immune complex:

A pair of immune system pieces. Immune complexes form when the immune system marks foreign objects so the body knows how to deal with them.

immunity:

A natural or acquired resistance to a specific disease. Immunity may be partial or complete; long lasting or temporary.

immunization:

To protect against disease by vaccination, usually with a weak form of the agent that causes illness. People are usually immunized against a disease by getting vaccinated, although having a disease one time usually prevents or "immunizes" you from getting it again. This may not always be true with people who are HIV positive.

immunomodulators:

Drugs hoped to strengthen the immune system and help the body fight off opportunistic infections or other diseases that attack people with AIDS. Not necessarily used to stimulate the immune system, which may be harmful. This includes two sub-groups: cytokines and "broad acting" immune modulators. Broad acting immune modulators are chemical transmitters/hormones in the body which regulate the immune system (i.e., endorphins), or act in a similar fashion.

inclusion/exclusion criteria:

The medical or other reasons why a person may or may not be allowed to enter a trial. For example, some trials do not allow pregnant women to join, others do not allow people to take certain drugs, and others exclude people with certain illnesses. Other trials may try to include pregnant or nursing women.

IND or investigational new drug:

The name given to an experimental drug after the FDA agrees that it can be tested in people.

indication:

Purpose for which a drug is intended; e.g. Pentamidine is indicated for PCP.

induction chemotherapy:

High doses of drugs in the first period of treatment, usually for cancer but also for CMV.

inflammatory bowel disease (IBD):

A disorder of the colon that causes stomach pain, constipation, and diarrhea.

informed consent:

Type of protection available to people considering entering a drug trial. Before entering the trial participants must sign a consent form that contains an explanation of a) why the research is being done; b) what researchers want to accomplish; c) what will be done during the trial and for how long; d) what risks are in the trial; e) what benefits can be expected from the trial; f) other treatments available; and g) the right to leave the trial at any time.

infusion:

The process of giving a substance (medication, food supplements, etc.) to an individual by injecting it into a vein. This procedure can either be a one-time event or continued over many hours, days or even months.

inhibitor:

In medicine, refers to a drug or chemical or substance that inhibits or blocks something from happening.

Institutional Review Board (IRB):

Every institution or hospital that conducts research involving human subjects must have an IRB that approves and periodically reviews the research. The IRB protects the rights of the people in the trial, determines who can participate in the trial, and whether the trial is ethical.

interaction:

Change in the body's response to one drug when another is taken. Interaction may increase the effect of one or both drugs, decrease the effect of one or both drugs, or cause toxicity.

interferon:

A substance that is produced when the body senses an infection with a virus. Interferon is released to coat uninfected cells so that they don't become infected. There are three main classes of interferon alpha, beta, and gamma.

interleukin:

A natural blood substance that helps immune system cells to communicate.

intestinal malabsorption:

A condition in which the nutrients found in food are not absorbed by the body. It can lead to malnutrition and weight loss.

intralesional:

Injected directly into a lesion.

intrathecal:

Injected into the fluid surrounding the spinal cord.

intravenous (IV):

Intravenous drugs are injected directly into the veins.

intravitreal:

In the eye.

in vitro:

(Latin for "in glass") An artificial environment created outside a living organism, e.g., a test tube or culture plate, used in experimental research to study a disease or process.

in vivo:

(Latin for "in life") Studies conducted within a living organism, e.g., animal or human studies.

IRB:

See Institutional Review Board.

ischemia:

Not enough blood in one area of tissue because blood flow is stopped.

J

K

Kaposi's sarcoma (KS):

A cancer of the blood vessels that may occur in people with AIDS. Blood vessels which grow rapidly and cause pink to purple, painless spots on the skin. Kaposi's sarcoma (KS). Lesions may first appear on the feet or legs and on the soft palate of the mouth. They may also remain hidden in the internal organs. KS can also grow in other places such as the lungs. It can be accompanied by fever, enlarged lymph nodes and stomach problems.

Karnofsky score:

A measurement system for how you perform everyday tasks. If you can eat and get dressed by yourself then you probably have a high Karnofsky score. It goes down as you need more help in doing things.

killer T cells:

A class of immune system cells that function to kill cancer and virus- infected cells; also called "Natural Killer" cells.

L

latency:

The period when an organism is in the body, but is not producing any ill effects. HIV is never really latent, although you may not have symptoms or feel bad.

lesion:

Any pathological or traumatic discontinuity of tissue, which may cause a loss of function (of the affected or surrounding tissue).

leukocytes:

All white blood cells.

leukopenia:

A lower than normal level of leukocytes in the blood.

lymph glands:

Small immune system centers that are located all over the body. Lymph glands protect the bloodstream from infection by filtering out infectious particles.

lymphadenopathy:

Swollen, firm and possibly tender lymph glands. The cause may range from a temporary infection such as the flu, HIV, mononucleosis, to lymphoma (cancer of the lymph nodes).

lymphocytic interstitial pneumonia (LIP):

A type of pneumonia that affects 35 to 40% of children with AIDS. Children with HIV who have LIP are diagnosed as having AIDS.

lymphoma:

A cancer of the cells that are responsible for normal immune function. A type of cancer that may include symptoms such as lymph-node swelling, weight loss, and fever. The type of treatment depends on the appearance of the lymphoma under the microscope as well as the extent of the spread of the lymphoma. Treatment can involve either radiotherapy or chemotherapy, or a combination of both. In most cases of Hodgkin's disease and about 50 percent of non-Hodgkin's lymphoma, treatment can result in a cure.

lymphoproliferative response (LPR):

A test of immune system function. The test measures how well T-lymphocytes respond to disease-causing organisms such as HIV.

M

MAC:

See mycobacterium avium complex.

macrophage:

A large immune system cell that roams through the blood looking for foreign matter. These cells also alert the rest of the immune system when help is needed.

magnetic resonance imaging (MRI):

A non-invasive diagnostic technique that can provide information on the form and function of internal tissue and organs of the body.

maintenance therapy:

Use of a treatment or treatments even after the disease has been brought under control. Unless maintenance therapy is used against PCP pneumonia, for example, the disease will probably occur again.

malabsorption syndrome:

Decreased intestinal absorption resulting in loss of appetite, muscle pain and weight loss.

malignancy:

A tumor or cancer.

memory cells:

T cells that have been exposed to specific antigens and are able thereafter to proliferate upon repeat exposure to the same antigens.

meningitis:

Inflammation of the brain and spinal cord that is usually caused by bacteria or a virus.

microsporidiosis:

An infection of the gut caused by a parasite. The main symptom is diarrhea.

molluscum contagiosum:

A skin disease caused by a virus which causes small rounded tumors. They are persistent but have no other general symptoms

monoclonal antibodies:

Custom made immune system pieces that are used against one specific disease causing agent.

MRI:

See Magnetic Resonance Imaging.

MTB:

mycobacterial tuberculosis.

myalgia:

Pain in one or more muscles.

mycobacterium avium complex (MAC):

A disease caused by an organism found in soil and dust particles. In PWAs, it can spread through the bloodstream to infect many parts of the body. Symptoms of MAC include prolonged wasting, fever, fatigue and enlarged spleen. It is usually found only in individuals who have T cells under l00. Though there is no cure, many different combinations of drugs are used to treat MAC. Also called MAI sometimes.

mycosis:

Any disease caused by a fungus.

myelopathy:

Neurologic disorder. Symptoms can be weakness of limbs, partial paralysis, inability to control legs, frequent urination and, in men, inability to get erections.

myelosuppressive:

Stopping bone marrow activity. A side effect of many drugs. The bone marrow is where blood cells and platelets are made.

myopia:

A condition in which the visual images come to a focus in front of the retina of the eye resulting in defective vision of distant objects.

N

naive:

Someone who hasn’t used a particular drug.

natural killer cells:

(NK cells) Large immune system cells that attack and destroy infected and cancer causing cells. They are known as 'natural' killers because they attack without any help from the rest of the immune system.

necrotizing:

Causing, associated with, or undergoing localized death of living tissue.

neoplasia:

Uncontrolled and progressive formation of any new or abnormal growth. Cancer.

neoplasm:

An abnormal and uncontrolled growth of tissue; a tumor.

neopterin:

A substance produced by macrophages when they encounter a foreign substance such as a virus. Doctors sometimes measure neopterin to see whether the immune system is fighting HIV.

nephropathy:

Kidney disease.

nephrotoxic:

Toxic or damaging to the liver.

neurodevelopment:

Development of neural tissue and the brain.

neuropathy:

Any abnormal, degenerative or inflammatory state of the peripheral nervous system.

neuropsychologic:

Body and mind behavior looked at together.

neurotoxic:

Poisonous or destructive to nerve tissue, including the brain.

neutropenia:

A low number of neutrophils in the blood. Neutrophils are a white blood cell important in defending the body against infections.

neutrophil:

A white blood cell which plays a central role in the immune system. Neutrophils are the immune system's main defense against bacterial infections.

night sweats:

Extreme sweating which happens during sleep. Night sweats are considered a symptom of HIV only when the body is drenched. Slight sweating is not a symptom.

NK cells:

See natural killer cells.

non-Hodgkin’s lymphoma (NHL):

Cancers of the lymphoid tissue which is part of the immune system. Similar to Hodgkin’s disease except more widespread at first. The most common sign is painless enlargement of one or more peripheral lymph nodes.

non-visceral:

Outside any internal organs of the body.

O

ocular:

Of or relating to the eye.

off label:

A drug prescribed for conditions other than those indicated on the label.

open trial:

A drug trial is "open" when doctors and participants know which drug is being administered, as opposed to a double blinded trial in which they do not know (some may receive a test drug or a placebo) until the trial is over.

open-label:

A type of drug trial in which researchers and participants know who is taking the experimental drug or the treatment being given.

opportunistic infection (OI):

Certain illnesses (such as PCP pneumonia) that people with AIDS can get and which can be life threatening. People with healthy immune systems do not usually get these illnesses, even though most people have the organisms that cause these illnesses in their body already. Only when the immune system is damaged can the organisms take advantage of the "opportunity" of this weakened state and cause damage.

oral (po):

Taken by mouth as a pill or liquid.

oropharyngeal:

Relating to the mouth and the pharynx. The pharynx is below the soft palate(the back of the mouth) and above the epiglottis(the flap of skin hanging down in the back of the mouth).

P

pancreatitis:

The pancreas is an organ of the human body attached to the small intestine, just past the stomach. The pancreas produce natural chemicals that digest food. Pancreatitis is a potentially fatal swelling or infection of this organ. Pancreatitis causes severe stomach pain that goes right through to your back, and can be a side effect of some anti-HIV drugs.

pancreatotoxic:

Damaging to the pancreas.

parallel track:

A system of distributing experimental drugs to individuals who are unable to participate in ongoing clinical trials.

parasite:

An animal or plant that lives inside or upon another living animal or plant without extending any benefit to it in return. Parasites kill millions of people worldwide every year, although some parasites are harmless. The usual means of infection is through contaminated water or poor washing habits. Rimming can also spread parasites.

PCR:

See polymerase chain reaction assay.

peripheral neuropathy:

A disorder of the nerves, usually involving the hands, feet, arms and legs. Symptoms may include numbness, a tingling or burning sensation, sharp pain, weakness and abnormal reflexes. In severe cases, paralysis may result. Can be a side effect of some drugs. This condition can often be successfully treated.

pH:

A measurement of hydrogen-ion concentration or activity signifying acidity (lowest is 1) or basicity (highest is 14). A low pH means too much acid.

pharmacokinetics:

The study of how much of a drug gets into the body and how long it stays there.

pharmacokinetic trials:

Trials which study how the drug is absorbed by the body. People in these trials often have blood tests every few minutes or hours. These trials often require a short stay in the hospital.

phase I study:

The first step in human testing of a drug. Designed to evaluate toxicity at different dose levels. Takes place with a small number of participants.

phase II study:

FDA drug testing phase for effectiveness in humans. The stage at which drug effectiveness is established. Proceeds only if Phase I studies show toxicity to be within acceptable levels. Usually involves 50 to 300 volunteers.

phase III study:

FDA drug testing phase for extensive clinical trials in humans. Expansion of phase II study to 300 to 3000 volunteers. Designed to back up information gathered in Phase I and II testing. Also compares the drug to other agents, either alone or in combination.

phenotypic test:

Phenotypic drug resistance is tested by growing the virus in the laboratory and seeing if it is resistant to the drug, regardless of what known or unknown mutations might be involved.

phenylketonuria:

High levels of a substance in the body called phenylalanine.

placebo:

A substance that has no effect on the body (often referred to as a sugar pill) that is given to one group in a placebo-controlled trial. In placebo-controlled drug studies, a placebo is given to one group of participants, while the drug being tested is given to another group. The results obtained in the two groups are then compared.

placebo effect:

A change that occurs when a placebo is taken. Although you may not actually be taking a real treatment you may still experience positive things because you want them to happen. The placebo effect usually wears off, although having a positive attitude may still be helpful in dealing with HIV.

platelet:

A blood cell that helps wounds to heal. Platelets also produce other helpful chemicals. HIV can decrease platelets and cause bleeding and other disease. A normal platelet count is between 200,000 to 300,000.

PML:

See progressive multifocal leukoencephalopathy.

pneumocystis carinii pneumonia (PCP):

It is a type of pneumonia caused by a fungus which grows rapidly in the lungs of people with AIDS. PCP pneumonia is the leading cause of death of people with AIDS, but it is both treatable and preventable. Anyone who is HIV positive should discuss when to take treatments that will prevent PCP with a doctor.

polymerase chain reaction assay (Amplicor, PCR):

An approved viral load test that measures the amount of HIV in a blood sample. The result provides information about the risk of disease progression. The test is also used to find out how well an anti-HIV treatment is working.

PPD:

A test for tuberculosis. If you are PPD positive you have been exposed to tuberculosis. This does not mean that you have the disease, although everyone who is PPD positive must be treated to avoid getting a serious and contagious form of tuberculosis.

progressive multifocal leukoencephalopathy (PML):

A viral infection of the brain that causes memory loss, motor control problems and loss of strength. PML can lead to coma and death.

prophylactic:

A drug that helps to prevent a disease before it occurs. For example, Bactrim is a prophylactic treatment that prevents PCP pneumonia.

prophylaxis:

Taking a drug to prevent yourself from getting an illness.

protease:

A substance in the blood that breaks down proteins. HIV has a protease enzyme that it uses to make more virus. Sometimes spelled proteinase.

protein:

Plants and animals are made of protein. Amino acids are the building blocks of protein.

protocol:

The plan for a clinical trial. A protocol explains why an experimental treatment is being studied and how it will be tested. A detailed plan which states a drug trial's rationale, purpose, drug dosages, length of treatment, how the drug is given, who may participate (inclusion/exclusion criteria).

protozoa:

A group of one celled animals, a few of which cause human disease.

psoriasis:

Skin disease of red patches covered with white scales. Common in people with HIV. Light treatments and steroid creams are effective.

p24 antigen:

A protein fragment of HIV. The p24 antigen test measures this fragment. A positive result for p24 antigen suggests that HIV is multiplying, although there is debate about this.

pulmonary:

About the lungs.

PWA:

Person with AIDS or people with AIDS.

Q

R

radiation therapy:

A treatment for cancer using radiation produced by a machine.

renal:

About the kidneys

renal failure:

When the kidneys stop functioning properly due to infection. HIV can sometimes cause renal failure.

resistance:

The ability of a disease to overcome a drug. For example, after long- term use of AZT, HIV can develop strains of virus in the body that are no longer suppressed by this particular drug, and therefore are said to be resistant to AZT.

retina:

Innermost covering of the eyeball on which the image is formed.

retinal depigmentation:

Loss of the normal coloration of the retina, the part of the eye that sees color, resulting in being unable to distinguish colors.

retinitis:

Inflammation of the retina, a part of the eye, which can be caused by cytomegalovirus (CMV) infection. If left untreated, CMV retinitis usually leads to blindness.

retinopathy:

Any various noninflammatory disorders of the retina including some that are major causes of blindness. The retina is the part of the eye that connects the image to the brain.

retrovirus:

Retroviruses are RNA viruses that transcribe their genetic material into DNA using an enzyme called reverse transcriptase.

reverse transcriptase:

An enzyme that is needed by HIV to get inside cells and make more of itself.

S

salvage therapy:

Treatment for individuals who don't respond to or who can't take other treatments for a condition.

seizure:

An attack of epilepsy which is a disorder of disturbed electrical rhythms of the central nervous system. The convulsive attacks usually come with clouding of consciousness.

sepsis:

A serious condition caused by uncontrolled growth of bacteria in the blood. This condition can lead to septic shock. This involves a sudden drop in blood pressure, changes in heart rate and temperature.

serum:

The clear portion of any body fluid. Blood serum is the clear liquid that separates from blood on clotting.

SGOT and SGPT:

A blood test to see if the liver is damaged.

shingles:

See herpes zoster.

short form written consent document:

A form that been verbally explained to an individual entering the trial. A witness must be present when the trial is explained and this form is signed.

side effects:

The action or effect of a drug other than that desired. The term usually refers to undesired or negative effects, such as headache, skin irritation, or liver damage.

sigmoidoscopy:

A procedure during which a small piece of tissue is taken from the lower intestine.

SOCA-certified:

SOCA stands for "Study of Ocular Complications in AIDS" and certified refers to the group of doctors studying treatments for eye disease associated with HIV infection.

spectroscopy:

Using an instrument called a spectroscope for developing and analyzing the band of wavelengths of electromagnetic vibrations. A kind of x-ray.

spinal tap:

See lumbar puncture.

STD:

A sexually transmitted disease.

Stevens-Johnson syndrome:

An allergic reaction called erythema, a redness of the skin due to congestion of the capillaries, causing flu like symptoms and severe lesions under the skin. Can be fatal.

stomatitis:

Swelling of the throat that is usually painful. Some drugs, such as ddC, may cause this condition.

subcutaneous:

Giving a drug by injecting it under the skin.

sulfa sepsis syndrome:

Sepsis is a blood infection from toxins. With sulfa sepsis syndrome, the toxin is sulfa.

surface antigen:

Antigens are any foreign substance. Cells take in the antigen and then put a piece on their surface to be recognized by T cells so it can be gotten rid of.

suppressor T cells:

T cells that turn other T cells off.

surrogate markers:

Laboratory tests that are used to measure disease progression. Different surrogate markers are being studied to see how well they measure the progress of HIV. The T4 cell count is a marker of how well the immune system is doing against HIV. Viral load is a new surrogate marker that seems to be able to measure disease progression better than the T4 cell count.

symptom:

a sign that the body is going through a process. A fever is a symptom of the body fighting off an infection. A rash is a symptom that the immune system is reacting to something such as dust.

synergism/synergistic:

When one drug increases the effectiveness of another one, it is said to have synergism with that drug. This effect is greater than you would expect from just adding the two drugs together.

syphilis:

A chronic contagious venereal and often congenital disease.

systemic:

Affecting the whole body.

systemic immunomodulary:

Drugs or treatments that affect immune responses.

systolic:

Contraction of the heart when blood is forced onward and the circulation is kept going.

T

3-fold:

The original amount x 3.

T cells:

White blood cells that play an important part in the immune system. There are three different types of T cells, each of which has different subsets. The commonly measured T cells are helper T cells, killer T cells, and suppressor T cells.

T-helper cell (T4 cell, CD4 cell):

A subset of T cells. Physicians regularly measure T-helper cell counts in HIV positive people. The normal range for T-helper cells is 480-1800, but may vary.

T-killer cell (cytoxic T cells):

A type of white-blood cell that kills foreign organisms after being activated by T-helper cells.

therapy:

Treatment of disease or disorders by drugs or methods.

TNF:

See tumor necrosis factor.

thrombocytopenia:

A condition in which platelets, a type of blood cell, fail to help blood clot. Treatment is either with drugs, removal of the spleen, or by platelet transfusion.

thrombophlebitis:

Inflammation of a vein because of the formation of a clot of blood within a blood vessel that won’t move.

thrush:

See candidiasis.

thymus:

The organ of the body that trains T cells to be part of the immune system.

toxic reaction:

A poisonous or unwanted reaction to a vitamin, drug or other substance. A toxic side effect is when a helpful medicine also causes some damage to the blood or body. Toxicity is a measurement of how much damage may be caused.

toxoplasmosis:

An inflammation of the brain caused by toxoplasma gondii, a parasite. Frequently causes inflammation of the brain. It may also involve the heart, lung, adrenal glands, pancreas and testicles. This disease is usually mild but it can cause fever and swollen glands, as well as severe headaches. Fifty percent of Americans have been exposed to toxoplasma gondii at some point in their lives.

transaminase:

An enzyme measurement that indicates the health of the liver.

transfusion:

The process of giving blood, or parts of the blood from one person to another. <

triglycerides:

Fatty substances in the blood. High levels can indicate liver malfunction or pancreatitis. Low levels can indicate malnutrition.

Treatment IND:

An FDA program that makes experimental drugs available to seriously ill people. Drug companies may charge for the drug, although most don't.

T-suppressor cell (T8 cell, CD8 cell):

A type of white blood cell that helps control the body's response to an infection.

tuberculosis (TB):

An infection caused by Mycobacterium tuberculosis. Treatment consists of the administration of a combination of antibacterial drugs, usually for at least nine months.

tumor necrosis factor (TNF):

A protein produced by macrophages. By itself, TNF destroys cancer cells. TNF can cause fever, chills, fatigue, headache, and inflammation. TNF causes weight loss and probably helps HIV to grow.

U

upper limit of normal (ULN):

Used to define range of blood work values. The upper limit is the highest number.

V

vaccine:

A shot or shots that prevent(s) a disease. Another kind of vaccine, treatment vaccines, are in development and being studied. Treatment vaccines may help fight HIV even after someone has been infected.

vaginal candidiasis:

Infection in the vagina with thrush. Presents with pain, itching, redness and white patches in the vaginal wall. Much more common and more difficult to treat in women with HIV infection.

varicella virus:

See herpes zoster virus.

viremia:

The presence of virus in the blood stream.

viral load:

The amount of measurable virus in the blood. Tests used to measure virus are PCR and bDNA.

virus:

The smallest known infectious organism. A group of infectious agents characterized by their inability to reproduce outside of a living cell. They are unable to live or multiply outside of a host cell since most do not possess the means to synthesize protein.

visceral:

About the internal organs of the body.

visual acuity:

How well the eye can see detail and tell objects.

W

wasting syndrome:

Severe weight loss involving depletion of muscle mass in people with AIDS and HIV positive individuals which can occur even in the absence of other infections. Unwanted weight loss of more than 10% of body weight plus either chronic diarrhea or chronic weakness and fever for more than 30 days. Treatment is required.

white blood cells:

Part of the immune system that protects the body against foreign substances such as disease-producing microorganisms.

X Y Z

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Last modified: 9/19/99
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