Dear Ask The Doctor: Hello, when I was pregnant I was diagnosed with oral hairy leukoplakia. As soon as i was diagnosed with it my doctor tested me for hiv. I had 3 different hiv tests done including the western blot test which he said was very accurate. When I was tested with the western blot would that detect the Hiv 2 virus? I still have signs of OHL but have tested several times negative, so I was wondering if it could possibly be HIV 2 and the tests that were used just didn't detect it. So using the most common hiv tests, do they tests for hiv 1 and 2? Thank you, and i'm very concerned about this.
Dear Patient: Like the ELISA procedure, the western blot is an antibody detection test. However, unlike the ELISA method, the viral proteins are separated first and immobilized. In subsequent steps, the binding of serum antibodies to specific HIV proteins is visualized. There are no universal criteria for interpreting the western blot test: The number of viral bands that must be present may vary. If no viral bands are detected, the result is negative. Almost all HIV-infected persons with indeterminate western blot results will develop a positive result when tested in one month; persistently indeterminate results over a period of six months suggest the results are not due to HIV infection. However for those individuals that have had high-risk exposures to individuals where HIV-2 is most prevalent, Western Africa, an inconclusive western blot test may prove infection with HIV-2. HIV-2 is a retrovirus different from HIV-1 but related to it. HIV-2 is found mostly in West Africa and in countries with large West African population immigrants. Most enzyme immunoassays (EIAs) currently in use detect antibody to HIV-2 as well as HIV-1.