by Carolyn Chu, MD, MSc, AAHIVS, AAHIVM Chief Medical Officer

September 7, 2021

Featured Literature:

Boyce CL, Sils T, Ko D, et al. Maternal HIV drug resistance is associated with vertical transmission and is prevalent in infected infants. Clin Infect Dis. 2021 Sept 1; ciab744. doi: 10.1093/ cid/ciab744. PMID: 34467974.

This case-control study involving the Promoting Maternal and Infant Survival Everywhere (PROMISE) cohort examined HIV genotypes of participants who transmitted HIV compared to participants who did not transmit to their infants. Investigators aimed to assess if maternal plasma HIV drug resistance is associated with increased transmission risk and to describe dynamics of NNRTI resistance in infants who acquired HIV. 48 infants were identified as having acquired HIV in utero/peripartum, compared with 37 infants who acquired HIV via breastfeeding. Adjusted analyses of in utero/peripartum transmission cases indicated that maternal HIV drug resistance, maternal plasma HIV RNA at infant diagnosis, enrollment CD4 count, and antepartum regimens were not associated with transmission. By contrast, for infants who acquired HIV via breastfeeding, maternal drug resistance and high maternal HIV RNA at time of infant diagnosis were independently associated with transmission. At time of diagnosis, 52.8% of infants who acquired HIV via breastfeeding were found to have HIV drug resistance (compared to only 12.2% of infants with in utero/peripartum transmission). Mutations affecting in utero/peripartum transmission infants included single NNRTI mutations, whereas mutations affecting breastfeeding transmission infants included single NRTI, single NNRTI, multiple NNRTI, or dual-class mutations.

Author’s Commentary:

These results highlight an important issue in perinatal and postnatal HIV care, namely antiretroviral drug resistance and its possible impact on infant transmission (particularly breastfeeding-associated transmission). Every infant in PROMISE received 6 weeks of nevirapine prophylaxis, therefore findings from this study don’t clarify whether resistance detected in infants was transmitted or selected for by infant exposure to nevirapine. Nevertheless, investigators aptly suggest more potent ART regimens may be superior to infant nevirapine in preventing breastfeeding transmission, especially in areas with high prevalence of maternal NNRTI resistance. This may be an important consideration to be mindful of when caring for people with HIV who are pregnant (or thinking of becoming pregnant) and interested in breastfeeding.

The author has no conflicts of interest to disclose.

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