Virus-specific antibody-producing cells in blood and cerebrospinal fluid in acute Japanese encephalitis.

During an epidemic of Japanese encephalitis (JE) in northern Thailand, cerebrospinal fluid (CSF) leukocytes and blood leukocytes from 28 patients with suspected JE were tested for spontaneous in vitro synthesis of antibodies to JE virus (JEV). Sixteen patients were subsequently proven to be infected with JEV. Supernatant fluids of three-day cultures of unstimulated peripheral blood mononuclear leukocytes or unstimulated unfractionated CSF leukocytes were tested for JEV IgM and IgG antibodies with isotype-specific "antibody capture" radioimmunoassays.