Maternal immune response and clinical outcomes on NNRTI-based antiretroviral therapy (ART) following exposure to single-dose nevirapine (NVP) for prevention of mother-to-child HIV transmission (PMTCT)
Background: Single-dose mother-infant NVP is widely used for PMTCT, but enthusiasm for it has waned over concerns of viral drug resistance in exposed mothers.
Methods: We studied women under HIV care in Lusaka, Zambia, where both ART and NVP-based PMTCT are widely available. ART is initiated according to WHO guidelines; first-line regimens are NNRTI-based. We defined treatment failure as suboptimal CD4 response (<50 cells/uL increase at 6 months, >30% decline from peak, return to baseline), worsening WHO stage, or death.
Results: From May-04 to Nov-05, 4552 women initiating NNRTI-containing ART had data regarding peripartum NVP exposure. 445 (10%) had previously used NVP for PMTCT. Median time from NVP ingestion to ART initiation was 502 days (range=9-1701); 271 (81%) were exposed >180 days prior. Mean baseline CD4 count was higher in the NVP-exposed group, compared to those without exposure (177 vs. 146 cells/uL; p<0.0001). However, mean CD4 change from baseline did not differ at 6 (+150 vs. +145 cells/uL; p=0.69) or 12 months (+184 vs. +181; p=0.94). Findings remained after adjustments for age, WHO stage, baseline CD4, and recent tuberculosis. Among women reporting NVP use, mean 6-month CD4 change was similar among women with recent (<6 months) vs. remote (>6 months) exposure (+161 vs. +147 cells/uL; p=0.73). Overall, 18% failed treatment, but there was no difference by NVP exposure in multivariable analysis (adjusted hazard ratio [AHR]=1.2; 95%CI=0.9-1.5). When compared to non-exposed individuals, women with recent (AHR=1.5; 95%CI=0.9-2.6) and remote (AHR=1.1; 95%CI=0.8-1.5) NVP exposure appeared to have similar risks for treatment failure.
Conclusions: In this large programmatic ART cohort in Zambia, exposure to NVP for PMTCT was not associated with attenuated maternal immune response or worse clinical outcomes overall. Further studies are needed to determine the potential impact on treatment failure of timing between NVP exposure and ART initiation, particularly among women reporting recent NVP use.
AIDS 2006 - XVI International AIDS Conference
"B.Chi, et al.
Maternal immune response and clinical outcomes on NNRTI-based antiretroviral therapy (ART) following exposure to single-dose nevirapine (NVP) for prevention of mother-to-child HIV transmission (PMTCT).
Oral abstract session:
AIDS 2006 - XVI International AIDS Conference: