BACKGROUND: There is intense interest in the benefits and dangers of providing PI therapy to the H/M arising from the contradiction between the imperative to treat and the risk of producing resistant HIV. METHODS: A representative cohort of 132 HIV-infected H/M subjects has been sampled from shelters, free food lines and low income SRO hotels (less than $14/night). Subjects are interviewed quarterly on antiretroviral (ARV) use and adherence. Plasma HIV viral load (Roche Amplicor) and ARV resistance mutations (differential hybridization/ABI sequencing) are obtained quarterly. RESULTS: Cohort retention is 95% at 9 months. 23% of the cohort have received reverse transcriptase inhibitor (RTI) therapy only and 22% have received PI+RTI therapy. 80% of subjects report taking greater than 90% of prescribed doses. RP-HPLC drug levels are consistent with self reported adherence (88% detectable, n=17). At a median of 2.5 months of ARV therapy, 31% (PI/RTI), 14% (RTI), 6% (NoARV) of subjects had undetectable viral load (less than 400 copies, p=0.012). Mean viral load in PI/RTI group was 1.6 and RTI group was 0.5 logs less than those on no therapy(p=0.001). Most of the viral load difference was seen in those reporting greater than 90% adherence. Protease mutations were seen in 1/9 (codon 82) PI/RTI exposed subjects. Reverse transcriptase mutations were detected in 3/16 RTI exposed subjects(codons 185 or 215). No PI and I RTI (codon 41) mutations were seen in 15 ARV naïve subjects. Additional virologic results will be presented. CONCLUSION: H/M subjects on ARV therapy report good adherence, receive virologic benefit and have low rates of resistance with early therapy. The duration of benefit and wildtype virus require further study. (Authors)
