[Encephalitis and humoral immunity]

Fourteen children with viral infection of the central nervous system have been examined with respect to their function of humoral immunity. Serum concentrations of immune globulins have been measured and antibody titers determined. Iso- and hetero agglutinins as well as antibodies against diphtheria, pertussis, and tetanus if the children were vaccinated have been measured. Anti viral antibodies were tested if children reported the respective infection in their history. Selective antibody deficiency have been found in three children all of whom had normal serum IgG and two elevated IgM levels. These three children showed complications in the course of infection. Nine children had elevated serum IgM and titers of IgM-antibodies were also in or above the high normal range.