Diagnostic Usefulness of Cytokine and Chemokine Levels in the Cerebrospinal Fluid of Patients with Suspected Tuberculous Meningitis

In this study, we investigated the diagnostic utility of the cytokine profile of the cerebrospinal fluid (CSF) and enzyme-linked immunospot (ELISPOT) assays of patients with suspected tuberculous meningitis (TBM). We prospectively enrolled adult patients with suspected TBM, and CSF specimens were analyzed for 18 cytokines/chemokines and soluble programmed death protein 1 (PD-1) and programmed death ligand 1 (PD-L1). Enzyme-linked immunospot assays were performed on mononuclear cells from the CSF (CSF-MCs) and peripheral blood (PBMCs). A total of 87 patients with meningitis, including 42 TBM-suspected patients and 45 non-TBM patients, were enrolled. Excluding the 32 patients with possible TBM, 10 patients with TBM and 45 patients with non-TBM were finally analyzed. Levels of adenosine deaminase (ADA), interleukin 12 subunit β (IL-12p40), IL-13, macrophage inflammatory protein α (MIP-1α), and soluble PD-1 and PD-L1 in the CSF were significantly higher in the TBM group than in the non-TBM group ( < 0.05). The optimal cutoff values for the sensitivities and specificities of the test methods for diagnosing TBM with small samples of 10 cases of definite or probable TBM were as follows: ADA > 6.95 U/L, 70% and 81%; IL-12p40 > 52.04 pg/mL, 80% and 73%; IL-13 > 0.44 pg/mL, 90% and 47%; MIP-1α > 8.83 pg/mL, 80% and 62%; soluble PD-1 > 35.87 pg/mL, 80% and 63%; soluble PD-L1 > 24.19 pg/mL, 80% and 61%; CSF-MC ELISPOT > 13.5 spots/250,000 CSF-MC, 30% and 91%; and PBMC ELISPOT > 14 spots/250,000 PBMCs, 50% and 78%, respectively. Therefore, CSF IL-12p40, IL-13, MIP-1α, and soluble PD-1 and PD-L1 concentrations appear to be useful adjuncts for diagnosing TBM.