Tuberculostearic acid, a potential parameter for scoring system construction for tuberculous meningitis diagnosis.

Abstract

This study aimed to validate the value of tuberculostearic acid (TBSA) whether it could implicate the existence of Mycobacterium tuberculosis (Mtb) and assist for the clinical diagnosis of tuberculous meningitis (TBM). The patient's cerebrospinal fluid (CSF) specimen was collected through the lumbar puncture and detected for TBSA with gas chromatography/mass spectrometry. At the same time, gold standard tests, i.e., CSF direct culture, CSF smear microscopy, or nucleic acid amplification tests, for Mtb were routinely performed. Furthermore, we evaluated all patients by the Lancet consensus scoring system, which classifies suspected patients to "Definite (depend on gold standard results only)," "Probable (>10 pts without imaging or >12 pts with imaging information)," "Possible (6-9 pts without imaging or 6-11 pts with imaging)," and "Not (<6 pts or with alternative diagnoses)" TBM. In total, 140 patients were admitted for our study included 27 confirmed TBM patients and 50 TBSA-positive patients. Sensitivity (0.7407, confidence interval [CI] 95%: 0.5372-0.8889) and specificity (0.7345, CI 95%: 0.6432-0.8132) were calculated. The Lancet consensus scoring system was also applied to evaluate the possibility of TBM in suspected patients, finding that TBSA-positive patients showed a similar grouping distribution as the definite TBM patients. Our study implicates that the prospective utilization of TBSA is worth combining into a scoring system for characterizing the features of Mtb, showing a great potential of TBM diagnosis by TBSA in future.