HIV-1 and immunological changes during pregnancy: a comparison between HIV-1-seropositive and HIV-1-seronegative women in Nairobi, Kenya

Objective
To assess changes in the proportion of CD4 and CD8 T-lymphocyte profiles during pregnancy, at delivery and postpartum, and to determine whether HIV-1 infection affects the normal profile.

Design and methods
A total of 416 pregnant HIV-1-infected women and an age and parity-matched HIV-seronegative group of 407 pregnant women were enrolled into a prospective study on the impact of HIV-1 infection on pregnancy. Maternal blood was obtained for lymphocyte subset determination at enrolment, delivery and 6 weeks postpartum. Whole blood sample drawn in EDTA-containing tubes were used to determine T-helper/inducer (CD4) and T-suppressor/cytotoxic (CD8) cells by direct immunofluorescence using monoclonal antibodies.

Results
No relationship was found between gestational age and any immunological variable. The CD4 percentage was lower postpartum than antenatally, in both HIV-1-seropositive and seronegative women, but this was not true for absolute CD4 counts. CD8 absolute counts and percentages were significantly higher postpartum than antenatally. The differences between HIV-1-seropositive and seronegative women in changes over pregnancy in CD4 and CD8 cells and their ratio, were not statistically significant.

Conclusion
Our findings do not support a short-term synergistic effect of HIV-1 and pregnancy on the immune function as determined by T-lymphocyte subsets.