[Characteristics of CD4+T lymphocyte counts changed in antiretroviral-naive and antiretroviral-treated HIV-infected individuals' cohorts in Tianjin].

Objective

To characterize the dynamic changes in CD4+T lymphocyte (CD4) counts among HIV-infected individuals in Tianjin, China, under untreated and antiretroviral treatment (ART) conditions, and to provide evidence for optimizing HIV case management and prevention strategies.

Methods

The data were derived from the follow-up records of HIV-infected individuals aged 15 and above in Tianjin from 2005 to 2024, obtained from the Chinese Disease Control and Prevention Information System. Records were split into non-ART and ART phases as time-dependent cohorts, with the same HIV-infected individuals contributing to both phases before and after treatment initiation. A continuous-time Markov model was applied to both cohorts to estimate annual transition rates of CD4 counts across immunological categories. In addition, a linear mixed-effects model with natural splines was fitted to the ART cohort to characterize individual recovery trajectories stratified by baseline CD4 count levels.

Results

The non-ART cohort and the ART cohort enrolled 709 and 2 865 HIV-infected individuals, respectively. In untreated individuals, CD4 counts declined progressively: annual transition rates from ≥500 to 350-499, 350-499 to 200-349, and 200-349 to <200 cells/μl were 34.8% (95%CI: 30.3%-39.9%), 19.0% (95%CI: 16.1%-22.5%), and 9.3% (95%CI: 6.8%-12.7%), with mean sojourn times of 2.87, 5.25, and 10.73 years, respectively. After ART initiation, CD4 counts recovery followed a nonlinear pattern: transition rates from <200 to 200-349, 200-349 to 350-499, and 350-499 to ≥500 cells/μl were 91.8% (95%CI: 86.6%-97.4%), 63.7% (95%CI: 60.9%-66.6%), and 42.6% (95%CI: 40.9%-44.4%), with corresponding mean sojourn times of 1.09, 1.57, and 2.35 years.

Conclusions

CD4 count transition rates in non-ART HIV-infected individuals decreased as immunodeficiency progressed, while post-ART recovery rates varied substantially across CD4 count strata.