Immunofluorescent detection of antibody to lymphocytic choriomeningitis virus in man.

The indirect method of immunofluorescence was applied to the detection of antibody in lymphocytic choriomeningitis (LCM) of man. In contrast to antibody demonstrated by complement fixation or neutralization by the footpad response method in mice, immunofluorescent antibody in the 12 cases tested was at maximal titer in the first specimens as early as 1 or 6 days after the onset of meningeal symptoms and declined slowly after several months. Antibody was detected by immunofluorescence as long as 3 years after illness. One hundred forty-five sera from 98 persons were tested, including 9 known to have had LCM infection. Three previously unrecognized infections were identified by the immunofluorescent method in laboratory personnel who had been exposed to animals infected with LCM virus. Maximal titers of LCM antibody varied in the 12 cases from 16 to 256. The method of immuno-fluorescence was specific and sensitive and was of diagnostic significance in the early stages of the clinical LCM disease.