Cytokines and chemokines in viral encephalitis: a clinicoradiological correlation

Abstract

Japanese encephalitis (JE) is the commonest encephalitis in South East Asia associated with high morbidity and mortality. Neuronal injury is attributed to a number of proinflammatory cytokines. This study evaluates cerebrospinal fluid (CSF) cytokines and chemokines in encephalitis and correlates these with clinical and magnetic resonance imaging (MRI) findings. We examined 14 patients with encephalitis (8 JE, 1 dengue, 5 nonspecific encephalitis) and 10 healthy controls. CSF cytokines (IL-1β, IL-6, IL-10, IL-12p70, TNF-α, IL-8) and chemokines (IP-10, MCP-1, MIG, IL-8 and RANTES) were estimated using Cytometric Bead Array, compared with controls and were correlated with severity of encephalitis, radiological findings and presence of movement disorders. Median age of the patients was 25.5 (range 6-55 years); 6 had seizures, 10 movement disorders and 6 out of 11 had MRI abnormalities. The MRI abnormalities included thalamic involvement in 5, basal ganglia and mid brain in 3 each and cortical involvement in 2 patients. Both the patients with cortical involvement had seizures and 5 of the 10 patients with movement disorders had thalamic, basal ganglia and/or mid brain involvement. There was significant increase in IL-6 (p = 0.01), RANTES (p = 0.02) and IL-8 (p = 0.02) in encephalitis compared to controls but there was no difference in IL12p70, TNF-α, IL-10, IL-1β and MCP-1. Cytokines and chemokines did not correlate with severity of encephalitis, radiological changes and presence of movement disorders. CSF IL-6, IL-8 and RANTES were significantly higher in encephalitis patients compared to controls.