Highly active antiretroviral therapy started during pregnancy or postpartum suppresses HIV-1 RNA, but not DNA, in breast milk

Background. The ability of highly active antiretroviral therapy (HAART) to reduce human immunodeficiency virus type 1 (HIV- 1) RNA and DNA in breast milk has not been described. Methods. We compared breast- milk HIV-1 RNA and DNA loads of women in Botswana who received HAART (nevirapine, lamivudine, and zidovudine) and women who did not receive HAART. Results. Women in the HAART group received treatment for a median of 98 days (range, 67 - 222 days) at the time of breast-milk sampling; 23 (88%) of 26 had whole breast- milk HIV-1 RNA loads < 50 copies/ mL, compared with 9 (36%) of 25 women who did not receive HAART (P = .0001). This finding remained significant in a multivariate logistic- regression model (P = .0006). The whole- milk HIV-1 DNA load was unaffected by HAART. Of women who received HAART, 13 (50%) of 26 had HIV-1 DNA loads < 10 copies/10(6) cells, compared with 15 (65%) of 23 who did not receive HAART (P = .39). Conclusions. HAART suppressed cell-free HIV-1 RNA in breast milk and may therefore reduce mother-to-child transmission (MTCT) of HIV-1 via breast-feeding. However, HAART initiated during pregnancy or early after delivery had no apparent effect on cell-associated HIV-1 DNA loads in breast milk. Clinical trials to determine MTCT among breast-feeding women receiving HAART are needed.