Disease progression, adherence, and response to protease inhibitor therapy for HIV infection in an Urban Veterans Affairs Medical Center

Indinavir therapy has demonstrated promise in the treatment of HIV-1 infection in clinical trials; however, its efficacy in a U.S. Veterans Affairs Medical Center, where access to therapy is generally unimpeded, is unknown. A review of the Miami cohort was conducted for the year beginning May 1996 to evaluate response to indinavir plus two nucleoside analogues. Of 483 HIV-1-positive patients (97% male; mean age, 46.7 ± 9.7 years), 266 were offered indinavir based on their having CD4 counts <200 cells/μl or viral loads >10,000 copies/ml. Of these patients, 36% were adherent and experienced significant reductions in viral loads (-93,325 ± 147,911 copies/ml) and elevations in CD4⁺ (111 ± 103 cells/μl) and CD8⁺ (225 ± 338 cells/μl) T cell counts. Adherent patients with baseline CD4 counts <100 cells/μl were 4.5 times more likely to have follow-up viral loads >10,000 copies/ml than those with CD4 >200 cells/μl. Adherent patients with CD4 counts <100 cells/μl did not show evidence of immune 'exhaustion' because they were equal to those with CD4 counts >200 cells/μl in their capacity to replenish CD4 cells. Nonadherence to the regimen resulted in loss of therapeutic benefit and suggested that strategies to enhance adherence may become an essential component of treatment.