ADA and meningeal tuberculosis: We included only those observational or cross-sectional and case-control studies from January 1980 to June 2022 that fulfill the following inclusion criteria: (1) reporting sufficient data to determine pooled sensitivity and pooled specificity for the diagnostic accuracy of CSF-ADA in TBM, (2) studies reporting CSF-ADA as a biomarker to differentiate between TBM and non-TBM cases, (3) reporting data in the English language, (4) conducted in age groups more than 18 years of age, (5) published as full-text article, and (6) published as original article.