Trajectories of CD4 T-cell count, CD8 T-cell count, and CD4/CD8 ratio in patients with HIV and long-term virological suppression based on Yunnan HIV cohort.

Objective: Our objective was to evaluate the trajectory of immunology in patients with HIV with different baseline CD4 T-cell count strata after antiretroviral therapy (ART) under long-term viral suppression.

Methods: This was a sub-analysis focused on patients with virological suppression for at least 5 years after ART. Data were obtained from the Yunnan HIV cohort in China. Patients were categorized according to prespecified baseline CD4 T-cell counts. The trajectories of CD4 T-cell count, CD8 T-cell count, and CD4/CD8 ratio changing over time were fitted using a B-spline regression model. The Cox proportional hazards regression model was used to assess the association of baseline CD4 T-cell count with the risk of both immunological responder (IR) and CD4/CD8 ratio normalization.

Results: A total of 2618 patients with a median follow-up of 7.25 years (interquartile range [IQR] 5.92-8.75) were included. Over a period of 12 years, the mean CD4 T-cell count remained above 500 cells/μL in all groups. The mean CD4/CD8 ratio was solely normalized in patients whose baseline CD4 T-cell counts were above 350 cells/μL. Patients with higher baseline CD4 T-cell counts showed higher risks of both IR and CD4/CD8 ratio normalization than those with the lowest (all p trend <0.001). A higher baseline CD4 T-cell count predicted a shorter time for both IR and CD4/CD8 ratio normalization.

Conclusions: Long-term, sustained viral suppression may not be able to fully normalize immunological functions in patients with HIV. A high baseline CD4 T-cell count benefits IR and CD4/CD8 ratio normalization.