Laboratory diagnosis of human immunodeficiency virus type 1 infection by polymerase chain reaction and viral culture in infants born to seropositive mothers. 735

The early and accurate diagnosis of human immunodeficiency virus type 1(HIV-1) infection in infants born to HIV infected mothers is essential for timely medical and social care. Study of the utility of viral detection methods is important to determine which may be the preferred diagnostic tool in this population. The accuracy of both polymerase chain reaction (PCR) and viral culture was assessed over a period of seven years on a total of 795 blood samples from 395 HIV-exposed children (of which 123 patients were HIV infected). Peripheral blood mononuclear cells (PBMCs) were obtained by Ficoll-Hypaque gradient centrifugation and processed for PCR and culture. For qualitative viral isolation, patient samples were co-cultivated with PHA-stimulated donor PBMCs and monitored for 28 days using a p24 antigen-capture method. PCR amplification was performed using the gag primer pair SK38/39 and detection of DNA was done with 32P-labeled SK19 probe, gel electrophoresis and autoradiography. Of the 795 samples tested, 505 were from children 12mo, sensitivities ranged from 96-100% and specificities ranged from 99-100% for both PCR and culture. Positive and negative predictive values were 97-100% and 98-100%, respectively, for both assays. Only nine patient samples produced discordant results between PCR and culture. We conclude that both viral culture and PCR are highly sensitive and specific methods for determination of HIV-1 infection in infants born to infected mothers. PCR may be the preferred technique, given that it is a more rapid and less labor intensive test.