Glial S100B is elevated in serum across the spectrum of West Nile virus infection.

INTRODUCTION

We previously reported that protein biomarkers of neuronal death and glial pathology were elevated in the cerebrospinal fluid of patients with West Nile virus (WNV) infection, including WNV fever. Therefore, we hypothesized that the glial biomarker S100B would also be elevated in serum across the spectrum of WNV disease.

METHODS

Serum levels of S100B were measured by enzyme-linked immunoassay (ELISA) in 90 WNV patients (35 with neuroinvasive disease and 55 with WNV fever) and compared with 34 healthy controls.

RESULTS

Serum S100B was significantly higher in patients (median 0.17 ng/ml) than in controls (0.09 ng/ml, P < 0.0001). Serum S100B was elevated in 16 cases (46%) with neuroinvasive disease and in 19 cases (35%) with WNV fever.

CONCLUSIONS

The increase in serum S100B reaffirms pathological changes across the spectrum of WNV disease. The elevated S100B in over one third of WNV fever cases implies that neuroinvasion occurs in a much greater proportion of patients than anticipated by clinical and epidemiological data.