AEGiS-15IAC: Persistence of nevirapine resistance mutations 6 months following single dose nevirapine.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Persistence of nevirapine resistance mutations 6 months following single dose nevirapine.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. ThOrB1353)

Morris L, Martinson N, Pillay C, Moodley D, Chezzi C, Lupondwana P, Ntsala M, Cohen S, Puren A, Sullivan J, Gray G, McIntyre J
National Institute for Communicable Diseases, Johannesburg, South Africa

BACKGROUND: We reported previously that 39.4% of women develop nevirapine (NVP) resistance mutations 7 weeks after a single dose of NVP used to prevent mother-to-child HIV-1 transmission. Here we present the data from the same cohort followed to 6 months.

METHODS: Samples from 155 HIV-1 infected women and 20 HIV-1 infected infants who were shown to have mutations conferring high level resistance to NVP (defined as K103N, V106A/M, Y181C, Y188C and G190A) at 7 weeks post-partum were assayed for the presence of mutations at 6 months post-partum using the HIV-1 ViroSeq Genotyping assay.

RESULTS: 55 of the 155 (35%) women who had evidence of resistance at 7 weeks had resistance mutations at 6 months. All 55 women had the K103N mutation, 2 of whom also had the G190A mutation. Viral load levels were higher among women who still had mutations at 6 months compared to those who had lost the mutations (113,000 versus 43,550 HIV-1 RNA copies/ml, p<0.05). Similarly CD4 counts were significantly lower among women who still had resistance mutations at 6 months (306 versus 363 cells/ul, p<0.05). Of the 20 children who had resistance at 7 weeks, 13 (65%) were found to have resistance at the 6 month visit, which included Y181C (n=10) and K103N (n=3).

CONCLUSIONS: The K103N and Y181C mutation persists in a proportion of women and children 6 months following single dose NVP, associated with higher viral levels and lower CD4 counts. The implications of this in terms of treatment options and subsequent pregnancies remain to be explored.

Keywords: AEGIS, Nevirapine, HIV-1, Viral Load, CD4 Lymphocyte Count, HIV-1 Reverse Transcriptase, Single Person, Mutation, Humans, Female, Child, Infant, genetics

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ThOrB1353