Require advice on tests

[bob2010]

Hi

Had a Antigen and antibody test in september approx.4-5 weeks after exposure, and same test again 7 weeks after, they both eventually  came back negative but did required more testing, as they originally showed positve/reactive. Trying to get hold of clinic for more information, but seems weather recently has restricted opening times.  Also had test at local GUM clinic - 3rd generation though i believe, which was also negative (also 7 weeks).

My question is why does this happen? I had illness second during 2nd test but fine during first test. Is this anything to be concerned about? I have read that this can happen, but a lot of the articles relate it to a autoimmune illnesses!

Trying to move on, as Teak in earlier post had answered my query on oral sex, but these tests have confused my thinking. Would appreciate more knowledgeable people in this particular field, to give me there views.

Thank you

[Vance2335]

I would assume you got a WB for a confirmation test and once as it comes up negative it is negative. If it comes up positive then they run the test again just to confirm.

So focus on negatives because clearly they are correct.

[bob2010]

  Thank you for your quick reply, you are correct in your analysis of my stress and anxiety, due to false positives.

Did not appreciate how many possible factors could cause false positives, do you believe then, that irrespective of initial test results, why or how they may have come about. The  final conformation from the lab of negative, which i presume would carry out numerous checks on result before issuing them. Is true? and is what i should focus on!

Regards

[Vance2335]

False positives happen, this is one reason why we don't recommend testing for people who had no risk. Because a false positive can happen which is going to cause that person a lot of stress and anxiety.

Factors Known to Cause False-Positive HIV Antibody Test Results

Anti-carbohydrate antibodies (52, 19, 13)
Naturally-occurring antibodies (5, 19)
Passive immunization: receipt of gamma globulin or immune globulin (as prophylaxis against infection which contains antibodies)(18, 26, 60, 4, 22, 42, 43, 13)
Leprosy (2, 25)
Tuberculosis (25)
Mycobacterium avium (25)
Systemic lupus erythematosus (15, 23)
Renal (kidney) failure (48, 23, 13)
Hemodialysis/renal failure (56, 16, 41, 10, 49)
Alpha interferon therapy in hemodialysis patients (54)
Flu (36)
Flu vaccination (30, 11, 3, 20, 13, 43)
Herpes simplex I (27)
Herpes simplex II (11)
Upper respiratory tract infection (cold or flu)(11)
Recent viral infection or exposure to viral vaccines (11)
Pregnancy in multiparous women (58, 53, 13, 43, 36)
Malaria (6, 12)
High levels of circulating immune complexes (6, 33)
Hypergammaglobulinemia (high levels of antibodies) (40, 33)
False positives on other tests, including RPR (rapid plasma reagent) test for syphilis (17, 48, 33, 10, 49)
Rheumatoid arthritis (36)
Hepatitis B vaccination (28, 21, 40, 43)
Tetanus vaccination (40)
Organ transplantation (1, 36)
Renal transplantation (35, 9, 48, 13, 56)
Anti-lymphocyte antibodies (56, 31)
Anti-collagen antibodies (found in gay men, haemophiliacs, Africans of both sexes and people with leprosy)(31)
Serum-positive for rheumatoid factor, antinuclear antibody (both found in rheumatoid arthritis and other autoantibodies)(14, 62, 53)
Autoimmune diseases (44, 29, 10, 40, 49, 43): Systemic lupus erythematosus, scleroderma, connective tissue disease, dermatomyositis
Acute viral infections, DNA viral infections (59, 48, 43, 53, 40, 13)
Malignant neoplasms (cancers)(40)
Alcoholic hepatitis/alcoholic liver disease (32, 48, 40,10,13, 49, 43, 53)
Primary sclerosing cholangitis (48, 53)
Hepatitis (54)
"Sticky" blood (in Africans) (38, 34, 40)
Antibodies with a high affinity for polystyrene (used in the test kits)(62, 40, 3)
Blood transfusions, multiple blood transfusions (63, 36,13, 49, 43, 41)
Multiple myeloma (10, 43, 53)
HLA antibodies (to Class I and II leukocyte antigens)(7, 46, 63, 48, 10, 13, 49, 43, 53)
Anti-smooth muscle antibody (48)
Anti-parietal cell antibody (48)
Anti-hepatitis A IgM (antibody)(48)
Anti-Hbc IgM (48)
Administration of human immunoglobulin preparations pooled before 1985 (10)
Haemophilia (10, 49)
Haematologic malignant disorders/lymphoma (43, 53, 9, 48, 13)
Primary biliary cirrhosis (43, 53, 13, 48)
Stevens-Johnson syndrome9, (48, 13)
Q-fever with associated hepatitis (61)
Heat-treated specimens (51, 57, 24, 49, 48)
Lipemic serum (blood with high levels of fat or lipids)(49)
Haemolyzed serum (blood where haemoglobin is separated from the red cells)(49)
Hyperbilirubinemia (10, 13)
Globulins produced during polyclonal gammopathies (which are seen in AIDS risk groups)(10, 13, 48)
Healthy individuals as a result of poorly-understood cross-reactions (10)
Normal human ribonucleoproteins (48,13)
Other retroviruses (8, 55, 14, 48, 13)
Anti-mitochondrial antibodies (48, 13)
Anti-nuclear antibodies (48, 13, 53)
Anti-microsomal antibodies (34)
T-cell leukocyte antigen antibodies (48, 13)
Proteins on the filter paper (13)
Epstein-Barr virus (37)
Visceral leishmaniasis (45)