Immunological markers in HIV-infected pregnant women. The European Collaborative Study and the Swiss HIV Pregnancy Cohort

Abstract

Objective: To examine immunological markers in HIV-infected pregnant women.

Design: Women enrolled in the European Collaborative Study and the Swiss HIV Pregnancy Cohort were followed throughout pregnancy according to similar clinical and immunological protocols. Information was recorded at various times during pregnancy and, in some centres, also 6 weeks and 6 months post-partum.

Method: Locally-weighted linear regression analysis was used to investigate changes in markers of cellular and humoral immune function during pregnancy and immediately post-partum, taking into account the serial measurement data structure. Women who received zidovudine during pregnancy were excluded.

Results: Four hundred and thirty-eight women had two or more measurements during pregnancy or within 6 months of delivery. Twenty-four per cent (106) of the women reported injecting drugs during pregnancy. Mean CD4 and CD8 cell counts declined to a low level 6 months before delivery, increased gradually until delivery and rose sharply to a peak level 3 months post-partum. In contrast, CD4 and CD8 percentages were stable during pregnancy, and increased slightly thereafter. The same pattern was evident for transmitting women, those delivered by Cesarean section, and women who injected drugs during pregnancy, and there was no evidence for an association with immunosuppression. Total immunoglobulin (Ig) G levels declined gradually throughout pregnancy until delivery, and increased in the 6 month post-partum period. Total IgM and IgA levels remained stable throughout pregnancy.

Conclusions: These findings suggest that pregnancy does not accelerate HIV progression, but in view of the intrinsic variability in serial CD4 counts, caution should be exercised when assessing changes in immunological markers in individual pregnant women.