CORRELATION BETWEEN HIV PROVIRUS BURDEN AND IN-UTERO TRANSMISSION

Objective: No predictive parameters of in utero or perinatal vertical transmission of HIV to newborns are known at present. Vertical transmi ssion may be related to several biological parameters of maternal HIV infection: (1) immunological parameters (neutralizing antibodies); (2) the concentration of viral particles and/or infected cells; and (3) t he selection of HIV subspecies of particular cellular tropism. The pre sent study was designed to examine the relationship between cellular v iral burden and transmission, and between maternal viral burden and CD 4+ cell count and clinical status at delivery. Method: We investigated mother-to-infant HIV-1 transmission at delivery in a cohort of 51 pai rs of mothers and newborns. Twelve infants were HIV-infected, as deter mined by successive polymerase chain reaction and culture determinatio ns within the first 6 months of life, and nine of these were diagnosed as HIV-infected during the first week of life. We determined peripher al blood mononuclear cell proviral DNA burden using a quantitative pol ymerase chain reaction assay. Polymerase chain reaction was performed in the HIV-1 gag gene, using [P-32]-end-labelled primers. External sta ndard DNA samples were from the 85-14 F2 cell line, which contains a u nique defective proviral DNA genome. Results: There was a linear relat ionship between the logarithms of c.p.m. and the number of HIV-1 DNA c opies. Conclusion: We have previously reported that the number of HIV provirus copies in maternal blood cells is related to transmission of the virus. Quantification of the HIV provirus by polymerase chain reac tion may be used as a predictive parameter of vertical transmission if accompanied by an exhaustive clinical and biological follow-up during pregnancy.