Short-term and long-term clinical and immunological consequences of stopping antiretroviral therapy in HIV-infected patients with preserved immune function.

BACKGROUND: The aim of this study was to assess the short-term and long-term consequences of stopping antiretroviral therapy (ART) in patients with preserved immune function. METHODS: This was a randomized 144-week follow-up CD4⁺ T-cell-count-guided treatment-interruption trial. HIV-1-infected adults with plasma HIV-1 RNA<50 copies/ml, CD4⁺ T-cell count >500 cells/µl and nadir CD4⁺ T-cell count >100 cells/µl were randomized to continuous treatment (CT) or treatment interruption (TI) until CD4⁺ T-cell count decreased to <350 cells/µl. The primary end points were AIDS-defining illnesses, death, CD4⁺ T-cell count <200 cells/µl, or virological failure after restarting ART. RESULTS: A total of 106 patients were included, 50 in the CT arm and 56 in the TI arm. A trend to a higher rate of primary end points was observed in the TI group (26.8% versus 14%, difference 12.8%, 95% CI -2.3, 27.8; P=0.105). In addition, 10 patients presented clinical events related with HIV rebound, including 8 cases of thrombocytopaenia. The CD4⁺ T-cell count significantly decreased in the TI group (even in patients with persistently high CD4⁺ T-cell counts and no clinical events) versus the CT group (median change -408 cells/µl versus -21.5 cells/µl; P<0.001), whereas a significant increase in CD8⁺ T-cell count was observed (256 cells/µl versus -59 cells/µl; P<0.001). The time to ART re-initiation was significantly associated with nadir and baseline CD4⁺ T-cell counts. CONCLUSIONS: Discontinuation of ART in patients with preserved immune function is followed by significant immunological impairment even in those with no clinical events, and may be associated with an increased risk of HIV-related complications. Hence, patients who stop ART voluntarily should be closely monitored, regardless of their CD4⁺ T-cell count.

Evolution of HIV-1 genotype in plasma RNA and peripheral blood mononuclear cells proviral DNA after interruption and resumption of antiretroviral therapy.

BACKGROUND: Structured antiretroviral therapy interruption (TI) is discouraged because of poorer AIDS and non-AIDS-related outcomes, but is often inevitable in clinical practice. Certain strategies could reduce the emergence of resistance mutations related to TI. METHODS: A total of 106 HIV-1-infected patients on stable HAART with undetectable plasma viral load were randomized to therapy continuation (n=50) or CD4(+) T-cell-guided TI (n=56). Staggered interruption involved stopping non-nucleoside reverse transcriptase inhibitors (NNRTIs) 7 days before the nucleoside backbone. Genotypic resistance testing (GRT) was performed on proviral DNA from peripheral blood mononuclear cells (PBMCs) at baseline and before each TI, and on plasma RNA after each TI. RESULTS: At baseline, GRT on PBMCs detected mutations in nine patients and only two major mutations were identified. GRT on plasma samples performed after TIs showed nucleoside reverse transcriptase inhibitors (NRTI), NNRTI and protease inhibitor major resistance associated mutations in 10/56, 3/46 and 1/8 patients receiving these drugs, respectively. Only in two patients had the same mutations been observed in GRT on PBMCs at baseline. Three patients presented virological failure after resumption of therapy, all receiving NNRTIs. In one of them, resistance mutations detected at failure had been also observed previously in GRT on plasma after TI. CONCLUSIONS: Staggered interruption of NNRTIs 7 days before the nucleoside backbone does not avoid resistance emergence completely, but does not necessarily lead to virological failure after treatment resumption. Plasma HIV-1 RNA genotype after the interruption and the patient's treatment history seem to be more useful than baseline proviral DNA genotype to assess the risk of virological failure after restarting therapy.