Maternal-fetal DNA admixture is associated with intrapartum mother-to-child transmission of HIV-1 in Blantyre, Malawi

Abstract

Background: The mechanism of mother-to-child transmission (MTCT) of HIV-1 is not well described.

Methods: Of 328 HIV-infected mother-infant pairs, we identified 91 that had discordant angiotensin I-converting enzyme and glutathione S-transferase M1 alleles. Maternal alleles in cord blood were quantified with real-time polymerase chain reaction, as indicators of microtransfusions.

Results: HIV-1 infected infants had more maternal DNA in cord blood than their uninfected counterparts. Increased maternal DNA in cord blood was associated with preterm delivery, low birth weight, and maternal immunosuppression.

Conclusion: Intrapartum MTCT was associated with placental microtransfusions. The associations among placental microtransfusion, in-utero MTCT, maternal immunosuppression, and poor birth outcome should be further investigated.

Figure 1

Box and whisker plots of factors associated with log₁₀ transformed maternal-fetal DNA admixture: (A) HIV-1 vertical transmission status, (B) preterm delivery (<37 weeks gestation), (C) low CD4 T-cell counts (<200 cells/ml), (D) low birth weight (<2500 grams). NT=uninfected infant; IU= in utero-infected infant; IP=intrapartum infected infant. Line represents median value, box edges represent 25^th and 75^th percentile, whisker edges represent upper adjacent values, and dots represent outside values. P-values were determined by the Wilcoxon rank-sum test.