HMGB1 level in cerebrospinal fluid as a complimentary biomarker for the diagnosis of tuberculous meningitis

Purpose: High mobility group box-1 (HMGB1) is a proinflammatory, DAMP protein that participates in many pathological conditions. In this study, we evaluated the usability of CSF HMGB1 as a biomarker for the diagnosis of tuberculous meningitis (TBM). Methods: A total of 59 TBM patients and 169 control patients were included in our study. CSF samples were obtained and analyzed for HMGB1 using a commercial ELISA kit. Results: The mean CSF HMGB1 was 19.36 ng/ml in TBM patients (n = 59) versus 3.12 ng/ml in non-TB meningitis patients (n = 30), 2.13 ng/ml in patients with extra neural tuberculosis (n = 73), and 1.06 ng/m in controls (n = 66). According to the receiver operator characteristic curves, a cut-off value of 3.4 ng/ml was calculated, indicating that the sensitivity and specificity of CSF HMGB1 alone in diagnosis of TBM were 61.02 and 89.94 %, respectively. In patients with extra neural tuberculosis and a high risk of TBM, CSF HMGB1 seemed to be a good candidate for early differential diagnosis of TBM at the cut-off value of 3.8 ng/ml, when the sensitivity and specificity were 79.49 and 94.52 % respectively. Conclusion: Our finding may prove to be clinically useful, because CSF HMGB1 ELISA can be performed in almost all clinical laboratories, especially when sophisticated technologies are either time consuming or unavailable.