Clinical profile and serum 25-hydroxyvitamin D deficiency in HIV-negative cryptococcal meningitis

Background Cryptococcal meningitis (CM) in HIV-negative individuals is on the rise, yet the role of vitamin D remains unclear. This study investigates serum 25-hydroxyvitamin D [25(OH)D] levels and their clinical implications in HIV-negative CM patients. Methods We conducted a retrospective case-control study of 93 HIV-negative CM patients and 191 healthy controls (HCs). Serum 25(OH)D levels, cerebrospinal fluid (CSF) fungal burden, cytokine profiles, the incidence of postinfectious inflammatory response syndrome (PIIRS), and one-year mortality were assessed. Logistic regression models identified predictors of mortality. Results CM patients had significantly lower serum 25(OH)D levels than HCs (18.33 vs. 23.69 ng/mL, p  < 0.001), with a higher rate of deficiency (< 20 ng/mL) in the CM group (59.14% vs. 34.03%, p  < 0.001). Lower 25(OH)D levels were associated with elevated CSF IL-6, IL-8, and IFN-γ levels ( p  < 0.05). Deficiency was linked to increased PIIRS incidence (43.64% vs . 21.05%, p  = 0.028). Logistic regression identified age and 25(OH)D levels as independent predictors of mortality, although deficiency was not associated with higher mortality. Conclusions Serum 25(OH)D deficiency is prevalent in HIV-negative CM patients and linked to neuroinflammation and increased PIIRS risk. Serum 25(OH)D levels may serve as a useful prognostic marker, although further research is needed.