A PILOT-STUDY TO EVALUATE THE DEVELOPMENT OF RESISTANCE TO NEVIRAPINEIN ASYMPTOMATIC HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PATIENTS WITH CD4 CELL COUNTS OF GREATER-THAN-500 MM(3) - AIDS CLINICAL-TRIALS GROUP PROTOCOL-208/

Treatment of human immunodeficiency virus (HIV) infection with nevirap ine in patients with <400 CD4 cells/mm(3) rapidly selects far virus wi th reduced susceptibility to nevirapine. To test whether resistance wo uld develop less quickly in patients with a lower virus burden, nevira pine was studied in asymptomatic patients with >500 CD4 cells/mm(3). W ith 400 mg of nevirapine daily, the median reduction in HIV RNA was 0. 51 log(10) copies/mL, and all isolates recovered by 12 weeks were resi stant to nevirapine, As in patients with lower CD4 cell counts, some p atients experienced sustained reduction in plasma HIV RNA despite the presence of resistant virus. These results suggest that lower levels o f HIV RNA and immunosuppression did not retard the rate of emergence o f nevirapine-resistant virus; also, a polymerase chain reaction-based HIV RNA assay is sufficiently sensitive to evaluate the antiviral effe ct of a drug in patients with >500 CD4 cells/mm(3).