Effect of recent thymic emigrants on progression of HIV-1 disease

Summary Background The concentration of T-cell receptorrearrangement excision DNA circles (TREC) in peripheralblood T cells is a marker of recent thymic emigrant T cells. We studied the predictive ability of measurements of TREC for clinical outcome in HIV-1-infected individuals. Methods We measured TREC in peripheral-blood mononuclear cells with a real-time PCR assay. We studied 131 Greek participants in the Multicenter Hemophilia Cohort Study who had known HIV-1 seroconversion dates. The prognostic value of baseline TREC, CD4 T-cell count, and HIV-1 RNA concentration was assessed by KaplanMeier and Cox’s regression analysis. Findings Four participants had progressed to AIDS by first blood sampling. Among the remaining 127 individuals, the median value of TREC per 10 6 cells was 6900 (IQR 2370–15 604). Baseline TREC values were lower in the 53 who progressed to AIDS than in those who did not (geometric mean 2843 [95% CI 1468–5504] vs 6560 [4723–9113] per 10