The association between comorbid conditions and CD4+ T-cell counts with in-hospital mortality of patients with moderate to critical COVID-19 disease

Abstract

BACKGROUND. COVID‑19 presents with variable severity, and identifying accessible prognostic markers is critical in resource-limited settings such as South Africa (SA), where the prevalence of HIV may influence immune response and outcomes. OBJECTIONS. To assess the association between CD4+ T-cell count and in-hospital mortality among patients with moderate to severe COVID‑19 infection in SA, with a focus on specific comorbid conditions. METHODS. This cross-sectional analytical study analysed data from the first COVID‑19 wave, using an electronic database compiled during the first wave of the epidemic as well as clinical records. During this period, 336 patients with moderate to critical COVID‑19 were admitted to Kalafong Provincial Tertiary Hospital in Pretoria, SA. The analysis included only those patients in whom CD4+ T-cell counts (n=270) were done. Mean CD4+ T-cell counts were compared between survivors and non-survivors using non-parametric statistics. Logistic regression was performed to adjust for confounders, with survival status as the outcome variable. RESULTS. Sixty-nine of the 270 patients (26%) died. Mortality rates by severity of COVID were moderate (7/49, 14.3%), severe (55/211, 26.1%) and critical (7/10, 70%) (p=0.001). Patients who were positive for HIV had significantly higher mortality (19/52, 36.5%) than HIV‑negative patients (50/218, 22.9%) (p=0.0436). Non-survivors had significantly lower CD4+ T-cell counts (p<0.001). After adjusting for age, hypertension, diabetes, pre-diabetes, renal disease, critical COVID‑19 disease and HIV status, the CD4+ T-cell count remained significantly lower in non-survivors (p<0.001). CONCLUSION. In patients with moderate to critical COVID‑19 disease, lower CD4+ T-cell counts were significantly associated with mortality, suggesting that this may serve as a useful marker for predicting outcomes.