Risk Factors for Cryptococcal Meningitis in People Living with HIV Who Test Positive for Cryptococcal Antigens in Blood: A Single-Center Study in a Resource-Limited Setting

Objective Cryptococcal infection is a common opportunistic infection among people living with HIV; if not effectively diagnosed, it can progress to cryptococcal meningitis (CM), which has a high mortality rate. High cryptococcal antigen (CrAG) titers in the blood predict CM in HIV patients; however, hospitals in resource-limited areas lack the means to measure these titers. Methods We manually collected data from the hospital information system on 107 HIV-infected patients aged ≥ 18 years who were admitted to Hangzhou Xixi Hospital between January 2012 and August 2023 and who tested positive for serum CrAGs via colloidal gold immunochromatographic assay. The data were divided into two groups (meningitis group and nonmeningitis group) to conduct a retrospective observational cohort study. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for the progression of patients with positive serological CrAG test results to CM, and ROC curves were constructed to further evaluate the predictive performance. Results Multivariate logistic regression analysis revealed that positive blood culture results (OR = 239.637; 95% CI: 15.838–3625.923; P < 0.001), the CD4/CD8 ratio (OR = 0.95; 95% CI: 0–0.084; P = 0.02), and headache (OR = 475.208; 95% CI: 30.611–7,377.148; P < 0.001) were significantly associated with progression to CM. ROC curve analysis of these three factors demonstrated moderately good predictive performance. The predictive probability of the overall model was high, with an AUC of 0.984 (95% CI: 0.965–1.000). The cutoff value for the CD4/CD8 ratio was 0.095, with a Youden index of 0.403, a sensitivity of 85%, and a specificity of 55.32%. Conclusion In resource-limited settings, among patients with HIV who test positive for blood CrAg, cryptococcemia, the CD4/CD8 ratio, and headache are significant independent risk factors for the development of CM. These findings have broad applicability and clinical utility in similar regions worldwide where blood CrAG titration testing is not available.