T lymphocyte subsets during and after pregnancy: analysis in human immunodeficiency virus type 1-infected and -uninfected Malawian mothers.

Flow cytometric studies were done in Malawi on 229 women in their third trimester and 128 women 6 weeks postpartum; both human immunodeficiency virus type 1 (HIV-1)-seropositive and -seronegative women demonstrated an increase in the absolute number of CD4 and CD8 lymphocytes between late pregnancy and early postpartum, while percentages of CD4 and CD8 cells remained virtually unchanged. Subsequent measurement of CD4 and CD8 cells 6 weeks after delivery in 89 women tested in the third trimester showed an increase in absolute numbers in both HIV-1-seropositive and -seronegative women, without a parallel increase in CD4 or CD8 percentage. Regardless of HIV-1 infection status, Malawian women are no more immunosuppressed, as measured by T cells, in their third trimester of pregnancy than in the nonpregnant state. Percentage, rather than absolute number, should be used when monitoring CD4 and CD8 cell levels in pregnant women to avoid the effect of higher volume of distribution on absolute numbers of T cells.