Cerebrospinal fluid lactate levels as a prognostic indicator in HIV-negative patients with cryptococcal meningitis: a retrospective cohort study

Abstract

Abstract Background Cryptococcal meningitis (CM) is a severe central nervous system infection. In patients with human immunodeficiency virus (HIV) infections and coexisting CM, elevated baseline cerebrospinal fluid (CSF) lactate levels can predict increased mortality. However, the CSF lactate level’s significance in HIV-negative patients with CM remains unclear, necessitating further investigation to elucidate the potential distinctions and enhance patient management. This study investigated the CSF lactate level significance in HIV-negative patients with CM. Methods This retrospective study utilized data from the clinical databases of patients who underwent lumbar punctures at a medical center in Kaohsiung City, Southern Taiwan. Demographic data, CSF lactate levels, routine CSF analyses, and hematological and neurological findings were evaluated. The optimal CSF lactate threshold value was determined using the Youden index. Results This retrospective study included 70 patients with CM, among whom 44 (63%) and 26 (37%) tested negative and positive for HIV, respectively. The group without HIV exhibited higher CSF lactate levels, with an optimal CSF lactate cut-off point for predicting 90-day mortality of 7.935 mmol/L, resulting in significant predictive accuracies (area under the curve, 0.755; sensitivity, 57.1%; specificity, 100%); this value was an independent mortality predictor in HIV-negative patients. In HIV-negative patients with CM, CSF lactate levels ≥7.935 mmol/L correlated with higher mortality rates but without statistical significance. All HIV-negative patients with CM and CSF lactate levels ≥7.935 mmol/L died within 3 months of admission. Conclusions HIV-negative patients with CM had elevated CSF lactate levels that correlated with adverse outcomes, enabling early identification of high-risk individuals.