[Detection of HIV infection by serologic procedures]

We briefly describe the principal techniques of antigen detection and discuss the pros and cons of routine screening and conformation assays. Regarding the differentiation of HIV 1 and HIV 2 infection, synthetic peptides corresponding to the antigenic epitopes of gp36 (HIV 2) and gp41 (HIV 1) yielded the best results. Commercially available antigen tests are relatively insensitive. New techniques, such as the polymerase chain reaction, allow the dedection of viral DNA in one infected cell out of 100,000 non-infected cells. However, since these methods are based on nucleic acid probes, they are rather laborious and cannot replace antibody tests; but they may be of use for early identification of HIV-infected infants or for the confirmation of the acute phase of the infection (CDCI). With regard to early prognosis--i.e. up to 2 years before the development of clinical symptoms__the following markers have been found useful: neopterine, beta-2-microglobulin, the lymphocyte subsets CD4, CD8, Leu2+7+, activated T-cells, as well as the decrease of antibodies against p31, p24 and p17.