International Clinical Virology Unit, UK.
The resistance of HIV clinical isolates with or without M184V was analysed in relation to plasma HIV-1-RNA level and time on therapy. The number of thymidine analogue mutations (TAMs) was lower in isolates with M184V, this was independent of plasma HIV-1-RNA level and time on therapy for T215F/Y, D67N and L210W. This suggests a direct effect of M184V on the reduced selection of TAMs. Lamivudine use was significantly associated with lower median fold resistance to zidovudine and stavudine.