COMPARISON OF CD4 AND CD8 LYMPHOCYTE RECOVERY IN HIV POSITIVE PATIENTS TAKING PROTEASE INHIBITOR VERSUS NON-NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITOR-BASED REGIMENS

M Jamil, J Douglas, K Thompson, WF Schlech
Department of Medicine, Dalhousie University, Halifax, Nova Scotia

Background: HIV-1 infection is associated with progressive loss of T lymphocytes, which can be reversed by modern antiretroviral therapy. Whether protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor- (NNRTI) based therapies lead to more rapid or sustained improvement is uncertain.
Objective: To assess differences in CD4 and CD8 T-cell responses to antiretroviral therapy in patients on a PI versus an NNRTI based regimen.
Study design: Chart review of 44 patients (27 on PI regimens and 17 on NNRTI-based regimens) was carried out. CD4, CD8 and viral load measurements were recorded at baseline and at 3-6 month intervals over >2 years. Data was entered into Microsoft Access and the SAS statistical package was used for analysis of the two groups.
Results: Over time there was a slight increase in CD4 cell count for PI and NNRTI groups and substantial variability was evident, and no difference in pattern of recovery between NNRTI and PI groups. Change over time was not significantly different between the two groups and no difference in pattern of recovery between the groups was noted. CD8 counts remained constant throughout therapy in both treatment groups, and change in CD8 over time was not significantly different. We observed a significant reduction in viral load in both groups, sustained through the follow-up period. Since the PI group had started earlier, substantial reductions in viral load may already have occurred in the NNRTI group from previous RTI-based regimens alone, preventing an analysis of the change in slope between the two treatment groups.
Conclusions: Increases in CD4 cell counts occurred in both PI and NNRTI treated patients, and there was no difference in the speed of recovery between the groups studied. Rapid decreases in viral load to undetectable levels occurred in both groups, and did not appear to be related to CD4 cell count rebound. CD8 counts remained stable throughout the study period in both groups.