By courtesy of nam aidsmap glossary – www.aidsmap.com
Abscess
A collection of pus formed as the product of infection.
Acute
A recently developed condition.
Adherence
The act of taking a treatment exactly as prescribed.
Adverse Event
An unwanted side-effect of a treatment
AIDS
Acquired Immune Deficiency syndrome A collection of specific illnesses and conditions which occur because the body's immune system has been damaged by HIV
Amylase
An enzyme produced in the pancreas and saliva which assists in the digestion of starch.
Anabolic
The metabolic processes that build new tissues.
Anaemia
A shortage or change in the size or function of red blood cells. These cells carry oxygen to cells of the body.
Anal intraepithelial neoplasia (AIN)
An abnormal growth on the surface of the rectum or anal canal which, when observed with a microscope, suggests that the cells could be malignant
Anergy
Lack of reaction by the body's defence mechanisms when foreign substances come into contact with the body. This may indicate the inability of the immune system to mount a normal allergic response.
Anorexia
Loss of appetite.
Anoscopy
Examination of the anal canal and lower rectum using a short speculum.
Antenatal
Before birth.
Antibiotic
A drug that affects bacteria
Antibody
protein substance produced by the immune system in response to a foreign organism.
Anticoagulants
Drugs that prevent the clotting of blood.
Antigen
Something the immune system can recognise as 'foreign' and attack.
Antioxidant
A vitamin, mineral or drug which can reduce the activity of free radicals, the unpaired electrons produced as a consequence of burning energy in a cell.
Antiretroviral
A substance that acts against retroviruses such as HIV.
Antiviral
A drug that acts against viruses.
Arthralgia
Pain in the joints.
Arthritis
Inflammation in the joints.
Assay
A test used to measure something.
Asymptomatic
Having no symptoms.
Ataxia
A lack of muscular co-ordination.
Atherogenic
Producing the most degenerative changes in artery walls.
Atherosclerosis
Hardening and narrowing of the arteries.
Atrophy
wasting due to nutritional imbalance, e.g. due to absorption problems caused by chronic diarrhoea.
Autonomic nervous system
The part of the nervous system that controls involuntary bodily actions.
B cell
A type of immune cell, responsible for making antibodies.
Bacteraemia
The presence of bacteria in the blood.
Bacteria
Single-celled micro-organisms.
Baseline
Starting point or value.
Basophil
A type of white blood cell also called a granular leukocyte, filled with granules of toxic chemicals, that can digest micro-organisms. Basophils are responsible for some of the symptoms of an allergy.
Bd
Abbreviation of a Latin term meaning twice daily.
Bid
Abbreviation of a Latin term meaning twice daily.
Bile
A fluid produced by the liver Partly a secretion of waste products and partly AIDS digestion by breaking down fats and assisting the absorption of nutrients.
Bilirubin
A chemical released by the liver as a result of damage caused by infection or drugs. Levels are assessed in the diagnosis of liver problems.
Bioavailability
How much of a drug is absorbed into the bloodstream.
Biopsy
A small sample of tissue that can be examined for signs of disease.
Blood-brain barrier
The name for the body's defence system which makes it hard for many substances in the blood to get into the central nervous system.
Bone marrow
Cells in the middle of bones which are responsible for producing blood cells.
Bronchoscopy
A medical procedure using a flexible fibre-optic tube that enables examination and biopsy of the lungs.
Buffalo hump
Fat accumulation on the back of the neck and shoulders associated with hormonal changes and lipodystrophy
Caesarean Section
Method of birth where the child is delivered through a cut made in the womb.
Candidiasis
A disease caused by the fungi of the candida family such as Candida albicans. Commonly known as thrush.
Carcinoma
A malignant tumour that may spread throughout the body.
Cardiovascular
Relating to the heart and blood vessels.
Cardiovascular disease
Includes CHD (about 50%), stroke (about 25%), and other circulatory system diseases.
CAT scan
Computerised axial tomography scan. A type of specialised X-ray that gives a view of a 'slice' through the body, and is used to help detect tumours, infections and other changes in anatomy.
Catheter
A tube that is implanted with one end within the body and the other remaining outside, to make it easier to get drugs into, or waste products out of the body.
CD4
A molecule on the surface of some cells onto which HIV can bind. The CD4 cell count roughly reflects the state of the immune system.
CD8
A molecule on the surface of some white blood cells. Some of these cells can kill other cells that are infected with foreign organisms.
Central nervous system
The brain and spinal cord.
Cerebral
Involving the brain.
Cerebrospinal fluid
The liquid surrounding the brain and spinal cord.
Cerebrovascular
Involving the brain and the blood vessels supplying it.
Cervical intraepithelial neoplasia (CIN)
Cancerous growth within the cells lining the cervix Untreated, it can lead to cervical cancer.
Cervix
The 'neck of the womb' at the top of the vagina.
Chemotherapy
The use of drugs to treat an illness, often denotes drugs used to treat cancer.
Cholesterol
A waxy substance, mostly made by the body and used to produce steroid hormones. High levels can be associated with atherosclerosis.
Chronic
A long-term condition.
Clades
The term for the different sub-types of HIV.
Clinical
A term referring to the nursing or medical care of patients.
Clinical event
The occurrence of a physical sign or symptom rather than an abnormality that can only be detected by laboratory tests.
Clinical trial
A research study involving participants, usually to find out how well a new drug or treatment works in people and how safe it is.
Clinician
A medical doctor who is active in looking after patients.
CMV
Cytomegalovirus, a virus that can cause blindness in people with advanced HIV disease.
CNS
Central nervous system.
Codon
A position within a gene.
Cohort
A group of people who share at least one common factor (e.g. being HIV positive) and who are studied over a period of time.
Coinfection
Having more than one infection at the same time. For example, when a person with HIV has hepatitis B or C. This can make disease worse and treatment more difficult.
Colitis
Inflammation of the bowels.
Colonoscopy
Examination of the large bowel using a video camera device.
Colposcopy
Examination of the surface of the cervix under magnification to identify the location and extent of abnormal lesions.
Combination therapy
Using more than one drug at a time.
Compassionate use
The release of an experimental drug by its manufacturer to people who are unable to obtain it in a clinical trial.
Compliance
An alternative term for adherence.
Contagious
An infection that can be spread easily, by casual contact.
Contraindication
A reason why a drug should not be used.
Control group
A group of participants in a trial who receive standard treatment rather than the experimental treatment which is being tested.
Coronary heart disease (CHD)
Occurs when the walls of the coronary arteries become narrowed by a gradual fatty build-up. Heart attack and angina are main symptoms.
Cross resistance
The mechanism by which HIV that has developed resistance to one drug may also be resistant to other, similar drugs.
Crossover trial
A clinical trial where participants are switched from one arm to the other part way through.
Cryptococcosis
A type of fungal infection usually affecting the membrane around the brain, causing meningitis It can also affect the lungs and chest.
Cryptosporidiosis
Infection with the gut parasite Cryptosporidium parvum and other species, causing severe diarrhoea.
Culture
Laboratory medium in which microbes can grow.
Cytokine
A natural chemical used to pass signals between cells.
Cytotoxic
Harmful to cells.
Cytotoxic T-lymphocyte
A type of white blood cell which kills virus infected cells.
Dementia
Changes in mental function, co-ordination and personality resulting from direct effects of HIV infection in the brain.
Dermatitis
Inflammation of the skin.
Diabetes
A condition characterised by raised concentration of sugar in the blood and urine, due to problems with the production or action of insulin.
Diagnosis
Description of the causes of a patient's medical problems.
Diarrhoea
Abnormal bowel movements, characterised by watery or frequent stools.
Disease progression
The worsening of a disease.
DNA
Deoxyribonucleic acid, the material in the nucleus of a cell where genetic information is stored.
Dose
Measured amount of a drug to be taken at one time.
Dose-ranging trial
A clinical trial where two or more doses of a drug are compared to see which works best and is least harmful.
Double-blind
A clinical trial where neither the researchers nor participants know which assigned treatment an individual participant in the trial is taking until after the end of the trial.
Dysplasia
Abnormal growth of cells.
Early intervention
Starting HIV treatment relatively early in the course of disease.
Efficacy
How well something works.
Encephalopathy
A disease or infection affecting the brain.
Endogenous
Coming from within.
Endoscopy
Viewing the inside of the body cavity with a flexible instrument using fibre optics.
Endpoint
An event used by aclinical trial to evaluate whether a trial therapy is working, e.g. developing AIDS or a rise in viral load above a certain level.
Enteric
Associated with the gut.
Enzyme
A protein which speeds up a chemical reaction.
Epidemiology
The study of diseases within a population.
Epidermis
The outer layers of the skin.
Epitope
The part of an antigen which the immune system recognises.
Epstein-Barr virus
The virus that causes oral hairy leukoplakia and glandular fever. Sometimes called mononucleosis.
Erectile dysfunction
A man's inability to have or maintain an erection, also known as ED or impotence.
Erythema
A red skin eruption or rash.
Erythropoietin
A natural hormone made in the kidneys to stimulate the production of red blood cells by the bone marrow.
Ethics committee
A panel of people which reviews any proposed clinical trial to ensure that the participants are protected from any foreseeable exploitation or harm. In the US known as the Institutional Review Board.
Exclusion criteria
Reasons that would disqualify a person from joining a trial.
Exogenous
Coming from outside the body.
Expanded access scheme
A programme that allows access to an experimental drug outside clinical trials for people in particular need.
First-line therapy
The regimen used when starting treatment for the first time.
Foetus
An unborn baby.
Folliculitis
Infection of the follicles, small sacs or glands in the skin such as those found at the base of hairs.
Fungi
A group of organisms, including the yeasts which cause candidiasis and cryptococcosis.
Fusion inhibitor
Anti HIV drug targeting the point where HIV locks on to an immune cell.
Gall bladder
The organ connected to the liver which stores bile.
Gastrointestinal
Relating to or affecting the stomach, gut or bowel.
Gastroscopy
Examination of the stomach using a fibre optic device.
Gene
A DNA sequence which determines the structure of a protein.
Genotype
The genetic make-up of an organism.
Giardiasis
An illness caused by the gut parasite Giardia lamblia.
Globulins
Proteins found in the blood and cerebrospinal fluid.
Glucose
A form of sugar found in the bloodstream. All sugars and starches are converted into glucose before they are absorbed.
Glutathione
A natural chemical used by the body to work against oxidative stress.
Glycogen
Glucose stored in cells, predominantly found in the liver.
Granulocytes
See neutrophil.
Granulocytopenia
A shortage of neutrophils.
Gynaecology
Study of medical conditions specific to women's reproductive organs.
HAART
Highly Active antiretroviral Therapy, a term used to describe anti HIV combination therapy with three or more drugs.
Haematokrit
Measurement of the proportion of red cells in the blood.
Haematology
Study of blood conditions. Also used to describe a range of biochemical tests carried out on the blood.
Haemoglobin
Red-coloured, oxygen-carrying chemical in red blood cells.
Haemophilia
Inherited illness in which the blood does not always clot, often requiring injections of blood clotting agents.
Half-life
The amount of time it takes for half a dose of any drug to be eliminated from the body.
Helper cell
An alternative name for CD4 T cells.
Hepatic
To do with the liver.
Hepatitis
Inflammation of the liver.
Hepatotoxicity
Side-effects affecting the liver.
Herpes simplex
A viral infection which may cause sores around the mouth or genitals.
Herpes viruses
Family of viruses which can cause disease in HIV infection, e.g. cytomegalovirus and herpes zoster.
hickman catheter
A type of catheter that is surgically implanted, with one end leading into a large vein in the chest, and the other end remaining outside the chest.
HICKMAN is a registered trade mark of C R Bard Inc
Histology
Examining a sample of cells under a microscope to determine if they are normal or if there is evidence of infections or tumours.
Historical control
A comparison group of people not taking an experimental drug, taken from previous clinical trials.
HIV
Human immunodeficiency virus the virus which causes AIDS There are two variants: HIV 1, and HIV 2. HIV 1 is by far the most common world-wide. See subtype for more information.
Homeopathy
A therapy which aims to treat illness using tiny quantities of the substance that caused the illness, or of a substance that causes similar symptoms.
Hormone
A chemical which stimulates or suppresses cell and tissue activity.
human papilloma virus (HPV)
A group of wart-causing viruses which are also responsible for cancer of the cervix and some anal cancers.
Hyper
Prefix meaning higher than usual.
Hyperglycaemia
Raised concentration of sugar in the blood.
Hyperlipidaemia
High levels of fat in the blood.
Hypersensitivity
An allergic reaction.
Hypertension
Raised blood pressure.
Hypertriglyceridaemia
High levels of triglycerides in the blood.
Hypo
Prefix meaning lower than usual.
Hypoxaemia
Reduced amounts of oxygen in the blood, usually caused by pneumonia.
IC50/IC90
The concentration of a drug needed to inhibit viral replication by either 50% (IC50) or 90% (IC90). IC stands for 'inhibitory concentration'.
Idiopathic
Disorder whose cause is unknown.
Immune modulator
A substance that changes an aspect of the way the immune system is working.
Immune reconstitution
Improvement of the function of the immune system as a consequence of anti HIV therapy.
Immune system
The body's mechanisms for fighting infections and eradicating dysfunctional cells.
Immunoglobulin
Another name for antibodies.
Immunologic response
The effect of treatment on the immune system particularly on the CD4 cell count.
Immunosuppression
A reduction in the ability of the immune system to fight infections or tumours.
In utero
Latin term meaning in the womb.
In vitro
Latin term for experiments conducted in artificial environments, e.g. in test-tubes.
In vivo
Latin term for experiments conducted in humans or animals.
Inclusion criteria
The conditions which a person must meet to join a clinical trial.
Informed consent
Agreement to take part in a clinical trial, or to take a test, after a full written or verbal explanation of the trial including the risks and benefits of taking part, has been provided by the researchers.
Insomnia
Sleeplessness.
Insulin
A hormone produced by the pancreas that tends to lower blood sugar levels.
Integrase
HIV enzyme that the virus uses to insert its genetic material into that of an infected cell.
Intention to treat analysis
A form of statistical analysis of clinical trials, where data from all participants enrolled in the trial is evaluated, rather than data only from those who complete the trial.
Interferon
A type of antiviral protein which stimulates the immune system.
Interleukin
A type of cytokine.
Intramuscular
Injected into a muscle.
Intrapartum
During the birth of a baby.
Intravenous
Injected into a vein.
Intravitreal
Injected into the eye.
Invasive
In medical terms, going inside the body.
Isosporiasis
An illness caused by the parasite Isospora belli.
Jaundice
A yellowing of the skin and whites of the eyes associated with liver or gall bladder problems.
Kaposi's sarcoma
Lesions on the skin and/or internal organs caused by abnormal growth of blood vessels.
Karnofsky score
A number between 0 and 100 which is assigned by a doctor to describe a patient's ability to function, as measured by the performance of common tasks.
KS
Short for Kaposi's sarcoma.
Lactate
Another name for lactic acid.
Lactic acidosis
High blood levels of lactic acid, a substance involved in metabolism lactic acidosis is a rare side-effect of nucleoside analogues.
Lesion
Any abnormal change in body tissue caused by disease or injury. Often refers to Kaposi's sarcoma which can cause skin lesions.
Leukocytes
White blood cells.
Leukopenia
Fewer than normal white cells in the blood, usually due to bone marrow damage.
Leukoplakia
A mouth infection caused by virus >Epstein-Barr virus /a> that can occur relatively early in HIV disease. Often called hairy leukoplakia due to its appearance as white patches on the sides of the tongue.
Libido
Another word for sexual drive.
Lipid
A general term for fats.
Lipoatrophy
Loss of body fat.
Lipodystrophy
A disruption to the way the body produces, uses and distributes fat.
Liver
An organ involved in digestion of food and excretion of waste products from the body.
Liver function tests
Tests evaluating the functioning of the liver.
Log
Short for logarithm, a scale of measurement often used when describing viral load A one log change is a ten-fold change, such as from 100 to 10. A two log change is a one hundred-fold change, such as from 1,000 to 10.
Lumbar puncture
A small hole made in the spinal column to take out spinal fluid for tests or to inject drugs. Also called a spinal tap. It involves the insertion of a needle through the tissue between the vertebrae to access the spinal canal.
Lymph nodes
Special areas in the body where white blood cells and other important immune cells are found. Also known as glands.
Lymphadenopathy
A swelling of the lymph nodes.
Lymphocyte
A type of white blood cell.
Lymphocytic interstitial pneumonitis
A type of lung problem, most commonly seen in children with HIV infection.
lymphoid tissue
Tissue involved in the formation of lymph fluid, lymphocytes and antibodies.
Lymphoma
A type of tumour affecting the lymph nodes.
Macrophage
A white blood cell that roams the body tissues engulfing foreign organisms.
Magnetic resonance imaging
Technique similar to CAT scanning.
MAI / MAC (Mycobacterium avium-intracellulare/Mycobacterium avium complex)
Micro-organisms related to TB which can cause disease in people with advanced HIV.
Maintenance therapy
Taking drugs for a period of time after an infection has been treated, to stabilise the condition or prevent a re-occurrence or deterioration.
Malabsorption
Failure of the gut to absorb food, resulting in weight loss, diarrhoea and decreased effectiveness of drugs taken orally.
Malaise
A general feeling of illness.
Malignant
Tumours which may grow rapidly, infiltrate surrounding tissues and spread around the body.
Mane
Latin term meaning day.
Mean
The average value (the sum of the observed values divided by their number).
Median
The central value of the distribution, so that half the values are less than or equal to it and half are greater than or equal to it.
Meningitis
Inflammation of the outer lining of the brain.
Meta-analysis
Where data from several clinical trials of the same thing, such as the use of a specific drug to treat a particular infection, are combined together to produce an overall result.
Metabolism
The mechanisms which sustain life, turning sugar and fat into energy.
Metabolite
Any chemical resulting from the process of metabolism.
Microsporidiosis
Infection with the gut parasite Microsporidia.
Mitochondira
Cellular compartment involved in energy production.
Mitochondiral toxicity
Mitochondria are structures in human cells responsible for energy production. When damaged by anti- HIV drugs, this can cause a wide range of side-effects, including possibly fat loss.
Monocyte
A white blood cell that roams the body tissues engulfing foreign organisms.
Monotherapy
Taking a drug on its own, as opposed to in combination with other drugs.
Mutation
A single change in gene sequence.
Myalgia
Muscle pain.
Mycobacteria
Family of bacteria that includes the causes of tuberculosis and MAI.
Mycosis
Any fungal disease.
Myelotoxic
Damaging to the bone marrow.
Myopathy
Muscle wastage or disease.
Nadir
Lowest out of a series of measurements.
Naïve
Never having taken anti HIV treatments before.
Named patient basis prescribing
A means of access to an unlicensed drug, in which a doctor requests supplies from its manufacturer for a specific individual.
Natural killer cells
Cells in the immune system which attack and destroy infected cells or tumour cells.
Nausea
Feeling sick.
Neoplasm
An abnormal and uncontrolled growth of tissue; a tumour.
Nephrotoxic
Damaging to the kidneys.
Neuralgia
A sharp pain along the path of a nerve.
Neurological
Relating to the brain or nervous system.
Neuropathy
Damage to the nerves.
Neutropenia
A shortage of neutrophils.
Neutrophils
Immune cells in the blood which can attack bacteria and fungal infections.
NNRTI
Non nucleoside reverse transcriptase inhibitor, the family of antiretrovirals which includes efavirenz, nevirapine and delavirdine.
Nocte
Latin term meaning night.
NRTI
Nucleoside analogue reverse transcriptase inhibitor, the family of antiretrovirals which includes AZT, ddI, 3TC, d4T, ddC and abacavir.
Nucleoside
One of the building blocks from which DNA and RNA are made.
Nucleoside analogue
Chemical which resembles a nucleoside Family of antiretrovirals which includes AZT, ddI, 3TC, d4T, ddC and abacavir.
Nucleotide analogue
Chemical which resembles a nucleotide. Family of antiretrovirals which includes tenofovir.
Observational study
A clinical trial which reports on an unfolding situation.
Obstetric
Relating to antenatal care.
Ocular
Relating to the eye.
Od
Abbreviation of a Latin term meaning every day.
Oedema
Accumulation of fluid below the skin or in the cavities of the body.
Oesophagus
The tube leading from the throat to the stomach.
OI
Opportunistic infection.
om
Abbreviation of a Latin term meaning every morning.
on
Abbreviation of a Latin term meaning every night.
open-label
A clinical trial where both the researcher and participants know who is taking the experimental treatment.
Opportunistic infection
Specific infections which cause disease in someone with a damaged immune system.
Paediatric
Of or relating to children.
Palliative
To do with relieving rather than curing symptoms.
Pancreas
A glandular organ situated behind the stomach that secretes insulin and pancreatic digestive enzymes.
Pancreatitis
A condition of the pancreas causing severe abdominal pain, shock and collapse, which can be fatal.
Pancytopenia
Low numbers of all blood cells.
PAP smear
A specimen of cells from the cervix usually obtained in scrapings from the opening, which may be examined by microscope to look for abnormalities.
Paraesthesia
Abnormal sensations of touch on the skin.
Pathogen
Any micro-organism which can cause disease. There are four main types: bacteria fungi protozoa viruses.
Pathogenesis
The ways in which disease is caused by a pathogen.
pc
Abbreviation of a Latin term meaning after food.
PCP
Pneumocystis carinii pneumonia, a form of pneumonia, which is an IDS defining illness.
PCR
Polymerase chain reaction, a method of amplifying fragments of genetic material so that they can be detected. Some viral load tests use this method.
Perianal
Around the anus.
Perinatal
Around the time of birth.
Peripheral neuropathy
Damage to the nerves of the hands and/or feet, causing symptoms ranging from numbness to excruciating pain.
Pharmacokinetic
The study of how a drug is absorbed and distributed throughout the body.
Phase I
The earliest stage of a clinical trial in humans, designed to see if a
drug, or vaccine is safe and what the maximum safe dose is.
Phase I/II
Stage of a clinical trial to see what the most effective dose of a drug
is.
Phase II
Stage of a clinical trial to see if a drug is effective in the short-term.
Phase III
Stage of a clinical trial when the experimental drug is given to large
numbers of people, at the dose determined in phase I or phase II Often the trial drug is compared with a treatment already in use or with an inactive placebo.
Phenotype
Trait or behaviour which results from a particular genotype.
Phosphorylation
Process by which the NRTI drugs are converted within human cells into forms that inhibit HIV.
PI
See protease inhibitor.
Placebo
A pill or liquid which looks and tastes exactly like a real drug, but contains no active substance.
Plasma
The fluid portion of the blood.
PML
Progressive multifocal leukoencephalopathy, a serious brain infection.
Poppers
Amyl, butyl or isobutyl nitrite, are recreational drugs sniffed during sex to both intensify the experience and relax anal sphincter muscles.
Preclinical
Of in vitro research or research involving animals, undertaken prior to research in humans.
Primary infection
The first few weeks after infection, e.g. with HIV.
Pro-drug
A drug that is broken down into another active form inside the body.
Prognosis
Likely outcome, such as the risk of disease progression.
Proliferation
Multiplication (e.g. of immune system cells) to control an infection.
Prophylaxis
Taking a drug to prevent an illness. Primary prophylaxis is the use of drugs to prevent a first occurrence of illness. Secondary prophylaxis is the use of drugs to prevent re-occurrence of illness.
Protease
An enzyme that HIV uses to break up large proteins into smaller ones from which new HIV particles can be made.
Protease inhibitor
Family of antiretrovirals which target the protease enzyme Includes amprenavir, indinavir, lopinavir, ritonavir, saquinavir, nelfinavir, and atazanavir.
Protein
A substance which forms the structure of most cells and enzymes.
Protocol
A detailed research plan that describes the aims and objectives of a clinical trial and how it will be conducted.
Protozoa
A group of single-celled animals, a few of which cause human disease.
Proviral DNA
The chemical form in which HIV s genetic information is stored within infected cells.
Psoriasis
A disease in which the skin develops raised, rough, reddened areas.
Psychiatry
A branch of medicine that treats people, using drugs and other physical methods, to change the way they act and feel.
Psychology
A branch of medicine that tries to explain why people act, think and feel the way they do.
Pulmonary
Affecting the lungs.
q4h
Abbreviation of a Latin term meaning every four hours.
qd
Abbreviation of a Latin term meaning once every day.
qw
Abbreviation of a Latin term meaning every week.
Radiotherapy
Treatment using radium or other radioactive matter.
Randomisation
The process of selecting by chance the treatment that a clinical trial participant will receive.
Recombinant
Genetically reconstructed.
Rectum
The last part of the large intestine just above the anus.
Regimen
A drug or treatment combination and the way it is taken.
Regression
Improvement in a tumour.
Remission
Partial recovery from an illness, an alternative word for regression.
Renal
Relating to the kidneys.
Replication
The process of viral reproduction.
Resistance
A drug-resistant HIV strain is one which is less susceptible to the effects of one or more anti HIV drugs because of its genotype.
Retinitis
Damage to the retina, the light-sensitive surface at the back of the eye.
Retrovirus
Family of viruses to which HIV belongs, that are distinguished by their use of RNA.
Reverse transcriptase
A retroviral enzyme which converts genetic material from RNA into DNA an essential step in the lifecycle of HIV.
RNA
Ribonucleic acid, the form in which HIV stores its genetic material.
Salvage Therapy
Any treatment regimen used after a number of earlier regimens have failed.
seborrhoeic dermatitis
A chronic inflammatory disease of the skin, characterised by dry, moist or greasy scaling, and yellow crusted patches.
Sepsis
The presence of pus-forming bacteria in the body.
Seroconversion
The time at which a person's antibody status changes from negative to positive.
Seronegative
Negative antibody result in a blood test.
Seropositive
Positive antibody result in a blood test.
Serum
Clear, non-cellular portion of the blood, containing antibodies and other proteins and chemicals.
Shingles
Condition caused by a herpes virus infection, involving painful blisters on the skin.
Sigmoidoscopy
Examination of the rectum and lower bowel with a flexible viewing device.
Simian
Related to or affecting monkeys.
Single blind
A type of clinical trial in which the participants do not know what treatments they are getting, but their doctors do.
Sinusitis
Inflammation or infection of the sinuses, which are cavities behind the forehead and cheekbones.
Speculum
An instrument for enlarging the opening of any canal or cavity in order to inspect its interior, e.g. vagina, rectum ear or nose.
Spleen
Organ which produces white blood cells and acts as a reservoir for red blood cells.
Splenomegaly
Enlarged spleen.
Sputum smear
A diagnostic test in which a sample of spit is examined under the microscope for the presence of micro-organisms.
squamous intraepithelial lesion (SIL)
Cancerous growth within the cells lining the cervix Untreated, it can lead to invasive cancer of the cervix.
Steroids
Drugs used to damp down excessive immune responses.
Strain
A variant characterised by a specific genotype.
Subcutaneous
Beneath or introduced beneath the skin, e.g. a subcutaneous injection is an injection beneath the skin.
Subtype (HIV)
Different strains of HIV which can be grouped according to their genes. HIV 1 is classified into three 'groups,' M, N, and O. Most HIV 1 is in group M which is further divided into subtypes, A, B, C and D etc. subtype B is commonmest in the UK, Europe and North America, whilst A, C and D are most important worldwide.
Superinfection
When somebody already infected with HIV is exposed to a different strain of HIV and becomes infected with it in addition to their exisitng virus.
Surrogate marker
An indirect indicator of something, such as measuring viral load to assess the treatment effect of a drug.
Symptom
A condition that results from or accompanies an illness or disease.
Symptomatic
Having symptoms.
Syndrome
A group of symptoms and diseases that together are characteristic of a specific condition.
Synergy
When two or more drugs produce an effect greater than adding their separate effects.
Systemic
Acting throughout the body rather than locally.
T cell
A type of immune system cell which is damaged in the course of HIV infection. CD4 and CD8 cells are both sub-types of T cell.
T helper cells
T cells that alert the immune system to produce cytotoxic T lymphocytes against a specific infection.
TB
Short for tuberculosis.
Teratogenic
Causing physical defects in the foetus.
Therapeutic vaccine
A vaccine like product used with the aim of improving the immune function of someone who already has an infection, rather than of preventing the infection.
Thrombocytopenia
A decreased number of specific cells in the blood responsible for blood clotting.
Thrush
A fungal infection of the mouth, throat or genitals, marked by white patches. Also called candidiasis.
Thymus
A gland in the chest where T cells produced in the bone marrow mature into effective immune system components.
tid
Abbreviation of a Latin term meaning three times a day.
Titre
A laboratory measurement of the amount, or concentration, of a given component in solution.
tiw
Abbreviation of a Latin term meaning three times a week.
Tonsils
Two oval lymph node-like structures situated where the mouth joins the throat.
Topical
Applied directly to the affected area, as opposed to systemic.
Toxicity
The extent or ways in which a drug is poisonous to the body.
Toxin
A poisonous substance.
Toxoplasmosis
A disease due to infection with the protozoa Toxoplasma gondii, usually causing inflammation of the brain.
Transaminase
An enzyme that can be measured in a blood sample that indicates the health of the liver.
Triglycerides
The basic 'building blocks' from which fats are formed.
Trough level
The lowest point to which levels of a drug fall in the blood between doses.
Tuberculosis
A disease caused by the bacterium Mycobacterium tuberculosis.
Tumour
Growth of tissues that perform no useful function, sometimes due to cancer.
Ulcer
A break in the skin or mucous membrane which involves the loss of the surface tissue.
Undetectable viral load
A level of viral load that is too low to be picked up by the particular viral load test being used.
Uveitis
Inflammation of the middle layer of the eye.
Vaccine
A substance that contains antigenic components from an infectious organism. By stimulating an immune response (but not disease), it protects against subsequent infection by that organism, or may direct an immune response against an established infection or cancer.
Vertical transmission
Transmission, for example of HIV from mother-to-baby.
Viraemia
The presence of virus in the blood.
Viral load
Measurement of the amount of virus in a sample. HIV viral load indicates the extent to which HIV is reproducing in the body.
Virion
A virus particle existing freely outside a host cell.
Virologic response
The effect of treatment on viral load.
Virological relapse
When viral load can be measured after previously being undectectable.
Virulence
The power of bacteria or viruses to cause a disease. Different strains of the same micro-organism can vary in virulence.
Virus
A microscopic germ which reproduces within the living cells of the organism it infects.
Visceral
Of or pertaining to the internal organs.
Vulva
The external female genitals.
Wasting
Muscle and fat loss.
White blood cell
The cells of the immune system including basophils, lymphocytes, neutrophils macrophages and monocytes.
Wild-type virus
Virus that has not been exposed to anti HIV drugs before.