Calprotectin and lactoferrin in the cerebrospinal fluid; biomarkers utilisable for differential diagnostics of bacterial and aseptic meningitis?

Abstract

The aim of our work was to assess the diagnostic contribution of calprotectin and lactoferrin determinations in the cerebrospinal fluid when distinguishing between bacterial and aseptic meningitides. In 23 patients with bacterial meningitis (BM) and in 50 patients with aseptic meningitis (AM), we determined the concentrations of calprotectin, lactoferrin and the conventional biomarkers like glucose, total protein, lactate and polynuclear count in the cerebrospinal fluid (CSF). The discriminative power of the various parameters studied was determined by means of receiver operating characteristic (ROC) curves: the area under the curve (AUC), sensitivity, specificity, the positive likelihood ratio (+LR), and the negative likelihood ratio (-LR). The diagnostic efficiency of calprotectin, lactoferrin, lactate, and polynuclear count when distinguishing between bacterial and aseptic meningitides, expressed by ROC curve parameters, was as follows: AUC (0.736, 0.946, 0.932, 0.932), sensitivity (86.2, 96.6, 90.0, 89.7), specificity (58.5, 92.4, 87.0, 90.6), +LR (2.08, 12.8, 6.9, 9.50), -LR (0.24, 0.04, 0.11, 0.11), respectively. The optimal cut point for calprotectin and lactoferrin was 191 ng/mL and 17.8 ng/mL, respectively. Our findings show, that the determination of lactoferrin in the CSF was diagnostically the most efficient marker in distinguishing between bacterial and viral meningitides. Calprotectin was far less efficient diagnostic marker. The polynuclear count and lactate concentration showed a very good diagnostic efficiency as well. The determination of protein and glucose was diagnostically less beneficial.