Nelfinavir monotherapy increases naïve T-cell numbers in HIV-negative healthy young adults

Although patients treated with HIV protease inhibitor (PI) containing regimens manifest increases in naïve T cell number, it is unclear whether this is due to reduction in viral replication or a direct drug effect. We questioned whether Nelfinavir monotherapy directly impacted naïve T-cell number in HIV-negative individuals. HIV-negative volunteers received Nelfinavir, 1250 mg orally, BID for 3 weeks, and T-cell receptor recombination excision circles (TREC) content in peripheral blood were assessed. Whereas TREC copies did not change over 3 weeks in untreated controls, TREC copies/copies CCR5 increased following Nelfinavir monotherapy in 8 patients (p < 0.02), and did not change in 7 patients (p = NS). Those patients who responded were younger than those who did not with a median age of 55 years for responders and 71 years for non-responders (p < 0.03). The increase in TREC was most pronounced in those patients less than 40-years old (p < 0.01). Moreover, the patients who did not increase TREC levels were more likely to have suffered a medical illness previously shown to reduce thymic function. In HIV-negative patients, monotherapy with the HIV PI Nelfinavir for 21 days increases TREC-positive naïve T cell number, particularly in individuals who are healthy and young.