A clinical rule for the prediction of meningitis in HIV patients in the era of combination antiretroviral therapy.

BACKGROUND: The diagnosis of meningitis in HIV patients is challenging due to altered immune responses. Diagnostic scoring systems were recently proposed for use in research settings to help prompt and easy differential diagnosis. The objective of this study was to create a clinical prediction rule (CPR) for meningitis in HIV-infected patients and to address the enigma of differentiating bacterial (BM), TB (TBM) and cryptococcal (CCM) meningitis based on clinical features alone, which may be enhanced by easy-to-obtain laboratory testing.

METHODS: We retrospectively enrolled 352 HIV patients presenting with neurological manifestations suggesting meningitis over the last 18 y (2000-2018). Relevant clinical and laboratory information were retrieved from inpatient records. The features independently predicting meningitis or its different types in microbiologically proven meningitis cases were modelled by multivariate logistic regression to create a CPR in an exploratory data set. The performance of the meningitis diagnostic score was assessed and validated in a subset of retrospective data.

RESULTS: AIDS clinical stage, injecting drug use, jaundice and cryptococcal antigen seropositivity were equally important as classic meningitic symptoms in predicting meningitis. Arthralgia and elevated cerebrospinal fluid Lactate dehydrogenase (LDH) were strong predictors of BM. Patients with cryptococcal antigenemia had 25 times the probability of having CCM, whereas neurological deficits were highly suggestive of TBM.

CONCLUSION: The proposed CPRs have good diagnostic potential and would support decision-making in resource-poor settings.