Comparison of central and local HIV-1 RNA quantification from two international clinical trials

Local and centrally measured plasma HIV RNA (pVL) were assessed for agreement in two trials, ENCORE1 and SECOND-LINE. The proportion less than 200 copies/ml at week 48 was qualitatively similar [ENCORE1 2.5% (95% confidence interval, 95% CI –1.6 to 6.6); 1.9% (95% CI –1.9 to 2.1); SECOND-LINE 0.3% (95% CI –6.4 to 10.0); 1.8% (95% CI –4.7 to 8.3)]. The mean difference in log10 pVL copies/ml at weeks 0 and 48 was less than 0.2 log10 copies/ml in both trials. Our data indicate that central testing of pVL in HIV therapeutic trials is not warranted.