Alpha-interferon responses in cerebrospinal fluid of patients with suspected meningitis.

Cerebrospinal fluid from 100 patients with clinically diagnosed meningitis was examined for alpha-interferon. In the laboratory four patient groups were identified: bacterial meningitis (n = 12), viral meningitis (n = 15), normal cerebrospinal fluid (n = 57) and abnormal cerebrospinal fluid (n = 16). A further 14 patients with cerebrospinal fluid shunts but no abnormality in the cerebrospinal fluid provided a control group for alpha-interferon determinations. The group with viral meningitis and the group with abnormal cerebrospinal fluid had significantly higher alpha-interferon concentrations (p less than 0.001) when compared with those of the three other groups. This assay had great predictive value in determining those patients with abnormal cerebrospinal fluid who did not have a bacterial cause of meningitis. As the groups with abnormal cerebrospinal fluid and viral meningitis had a similar spread in alpha-interferon values it is likely that both reflect viral infection of the central nervous system.