HIV-1 replication capacity and genotype changes in patients undergoing treatment interruption or lamivudine monotherapy.

The objective of this study was to investigate the mechanisms underlying the virological and immunological changes occurring in failing HIV-1 infected patients undergoing treatment interruption or lamivudine monotherapy (the E-184V Study). Associations were sought between the de-selection of individual reverse transcriptase and protease resistance mutations and replication capacity recovery, HIV-RNA changes, and immunological changes. The replication capacity recovery was defined as the ratio between the replication capacity at weeks 24 or 48, and that measured at baseline. The replication capacity recovery, which was evaluable in 21 patients at week 24 and in 18 at week 48, was significantly higher in the treatment interruption than in the lamivudine group at week 24 (P = 0.002). Forty-eight week replication capacity recovery was greater when the 184V (P = 0.023), the 41L (P = 0.02), or the 215Y mutation (P = 0.037) were deselected at week 12. A greater reduction in the CD4+/CD8+ ratio at week 48 (P = 0.038) was observed as the 184V mutation was deselected and the de-selection of the 184V mutation at week 12 was the only independent predictor of the change of the CD4+/CD8+ ratio at week 48 from baseline at multivariable analysis (F-value = 6.72, P = 0.021). In conclusion, among patients undergoing treatment interruption or lamivudine monotherapy, the recovery of HIV-1 replication capacity was associated with the de-selection of reverse transcriptase mutations. The de-selection of the 184V mutation predicts independently a reduction in the CD4+/CD8+ ratio. (Copyright) 2007 Wiley-Liss, Inc.