In line with previous literature suggesting that proteins associated with neutrophil activation (e.g. Myeloperoxidase, Lactotransferrin, S100 A8/9 (Calprotectin), S100B and Lipocalin 2) have high predictive accuracy in diagnosing bacterial meningitis, a systematic review and meta-analysis suggest that heparin binding protein (azurocidin) has high diagnostic accuracy for bacterial meningitis (pooled sensitivity and specificity ≥95%), (43)*. Here, MPO is linked to bacterial meningitis.