Diagnosis of Human Immunodeficiency Virus Infection by Polymerase Chain Reaction

Summary

Infection by the human immunodeficiency virus (HIV) is routinely diagnosed by the identification of specific antibodies in serum. In some cases, as in primary infection, HIV can be detected prior to seroconversion by the polymerase chain reaction (PCR), among other methods. Furthermore, there is a great need for accurate and early detection of perinatal HIV infection, as early diagnosis is complicated by the persistence of maternal antibodies. Another important question is posed by PCR positivity in seronegative individuals at risk of HIV infection, as available data are conflicting. We have developed a simple PCR with nested primers for the detection of HIV-1 and HIV-2. By this PCR protocol, 97% of unselected HIV-1 seropositive individuals were positive. HIV-1 infected persons who had an uninfected sexual partner or child were somewhat less often PCR positive (79%), indicating that contagiousness may be related to virus load. Seronegative persons at risk of HIV-1 infection (n = 55) were PCR negative. Also, in children born to HIV-1 infected mothers, there was excellent agreement between the results of PCR and other signs and symptoms of HIV-1 infection. However, PCR was the most sensitive method for the early diagnosis of perinatal transmission of HIV-1. In conclusion PCR is of great diagnostic value in selected cases. PCR positivity in persons who remain HIV seronegative for prolonged periods of time appears to be very rare.

This work was supported by the Swedish Medical Research Council (grant no. 16H-7737) and by the Labour Market Insurance Company (AFA).