Different Cytokine Levels in Enterovirus Meningitis and Encephalitis

Abstract

To investigate the role of cytokine in the pathogenesis of enterovirus central nervous system (CNS) infections, 14 children with encephalitis (6 infected by enterovirus 71) and 21 children with meningitis (14 infected by echovirus 30 and 7 infected by echovirus 6) were recruited. Serum and cerebrospinal fluid (CSF) specimens were tested for interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a). The results showed that only 1 of 14 (7%) meningitis children has a measurable TNF-a level in CSF. By contrast, 4 of 6 (67%) CSF specimens and 10 of 12 (83%) serum specimens in encephalitis children had detectable TNF-a. Children with meningitis tended to have a higher CSF IL-6 level with borderline significance (378 ′ 207 pg/mL vs. 153 ′ 157 pg/mL; P = 0.075), and had a significantly lower CSF TNF-a level (1.4 ′ 5.1 pg/mL vs. 109 ′ 87 pg/mL; P = 0.003) than children with encephalitis. CSF concentrations of IL-6 and TNF-a tended to be higher in those with confirmed EV71 infections than in other encephalitis children with a borderline statistical significance (P = 0.075 and 0.061. respectively). In conclusion, IL-6 response is more prominent in enterovirus meningitis, whereas TNF-a response is more prominent in enterovirus encephalitis. The difference in cytokine response may be one of the underlying mechanism accounting for different severities of various enterovirus CNS infection.