HIV Antibody Detection Methods: Current Approaches^†

Abstract

Human immunodeficiency viruses designated as HIV-1 and HIV-2 are the infective agents causing Acquired Immunodeficiency Syndrome (AIDS) in the infected patients. There is neither an effective vaccine nor treatment to contain HIV infection. The serodiagnosis of HIV infected patients as well as testing of the blood and blood-products used for transfusion and therapy are the only means available to check the spread of HIV and ensure the safety of the society. The two most widely used immunologic HIV IgG antibody detection methods namely, enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) have been evaluated. The evidence presented here shows that these HIV antibody detection tests are

not adequately standardized and lack reproducibility. A positive result in ELISA does not necessarily and always mean HIV infection and a negative result does not rule out infection. The protein bands observed in the confirmatory WB may not always be clue to proteins considered to be specific to HIV. These uncertainties can be minimized to a large extent but cannot be resolved completely at the present time due to lack of a gold standard or even a silver standard. The seronegative window period in which 1gM antibodies and antigenaemia appear, the gray zone of weak antibody response, the manifestations of cutoff values and not detecting IgA antibody, further complicate the problem. This necessitates reappraisal of antibody detection tests for diagnosis and epidemiology of the HIV infection. Physicians should be aware of specific causes of inaccurate results. In individual cases, knowledge of the patient's history and the criteria used by the testing laboratory are important. Strategies of combination of tests as experienced in Burkina Faso may be of value in the detection of HIV infection accurately and cost-effectively, particularly in the developing countries.