Pro-inflammatory (TNF-α) and anti-inflammatory (IL-10) cytokines for differentiating Haemophilus influenzae type b from other meningitis bacterial agents

Favorable treatment outcome is depending on accurate detection of meningitis etiological agent. Lately, increasing significance is attributed to the role of cytokines in bacterial meningitis differentiation. Herein, we aimed to evaluate the diagnostic significance of pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) and anti-inflammatory cytokine interleukin-10 (IL-10) in Haemophilus influenza type b (Hib) meningitis.

Methods: Ninety-six patients clinically suspected of bacterial meningitis (60 with Hib and 36 with non-Hib meningitis) were enrolled in this study. Serum and CSF level of TNF-α and IL-10 were quantified by ELISA. Diagnostic performances of single and combined cytokines were evaluated using area under ROC.

Results: Significant increase was noted in IL-10 and TNF-α levels in both CSF (P=0.004 and 0.009; respectively) and serum (P=0.007 and 0.010; respectively) in Hib meningitis patients compared to non-Hib meningitis patients. IL-10, and TNF-α had a discriminative capability for Hib meningitis diagnosis in CSF (AUC=0.75 and 0.77; respectively) as well in serum (AUC=0.72 and 0.78; respectively). The combined use of these cytokines (TNF-α ×IL-10) in CSF exhibited a valuable power (AUC=0.88, sensitivity=84% and specificity= 71%) for Hib meningitis detection. Interestingly, serum TNF-α×IL-10 combination showed also comparable discriminative power with AUC=0.85, sensitivity=83.3% and specificity= 78.6%.

 Conclusion: TNF-α and IL-10 cytokines are potential biomarkers for differentiating Hib meningitis from meningitis causing by other bacterial agents and the convenient combined of them can improve diagnostic efficiency of Hib meningitis particularly in serum, a less invasive sample, to aid or even replace lumbar puncture.