Microglial/macrophage markers CHI3L1, sCD14, and sCD163 in CSF and serum of pediatric inflammatory and non-inflammatory neurological disorders: A case-control study and reference ranges.

OBJECTIVE

To assess the role of microglia and macrophages in neuroinflammatory disorders in children via biomarkers, and establish control reference ranges.

METHODS

In an IRB-approved case-control study of 98 children, the concentrations of CSF/serum CHI3L1, sCD14, and sCD163 were measured by ELISA. Groups were controls (non-inflammatory neurological disorders, NIND, n=37), opsoclonus-myoclonus syndrome (OMS, n=37), and other inflammatory neurological disorders (OIND, n=24).

RESULTS

In control CSF, median concentrations (ng/ml) were 25 (IQR 16,41) for CHI3L1 and 42 (26,160) for sCD14; in serum, 16 (12,22) for CHI3L1, and 431 (270,957) for sCD163. The median CSF concentration of CHI3L1 in OIND was significantly higher than controls (2.9-fold, P<0.0001) and OMS (1.6-fold higher than controls, NS). The CSF sCD14 concentration was 1.9-fold higher in OIND (P=0.008) and 1.4-fold higher in OMS than controls. sCD163, below detection limits in CSF, was not significantly increased in OIND or OMS sera.

CONCLUSIONS

CSF CHI3L1 and sCD14 elevations hold promise as immunomarkers in pediatric OIND, especially in high-expression individuals. These results provide evidence of innate immune system involvement in several pediatric neuroinflammatory disorders. Pediatric control data on CSF microglia/macrophage activation markers are hereby available for other investigators.