Study on Precipitation Test for Sporotrichosis

Abstract

By a precipitation test using the culture filtrate of Sporothrix schenckii as antigen, the followings were investigated: 1) detection of blood antibody in patients with sporotrichosis and variation of antibody according to the activity of the disease, and 2) antigen titers associated with culture duration as well as the effect of heating on the antigenicity. The results were as follows:
1) Positive results were obtained in 22 of 23 patients with sporotrichosis and in 28 of 836 controls. Serologically, the reaction was generally “labile” in the fixed type of the disease and “stable” in the lymphatic type, however the clinical symptoms did not always parallel the antigen titers.
2) In a week culture filtrate of S. schenckii, the antigenicity was not observed and the strength of the reaction was found in the order of weeks 5≤9≤13≤17≤14. No decrease in reaction was noted even after heating the antigen. This shows that this antigen may be thermostable. Sporotrichin skin test was positive in all cases. In the precipitation test for sporotrichosis, the fixed type tended to be more reactive than the lymphatic type, however there was no difference in positive rate between both types. In experiments with rabbits immunized with heat-killed S. schenckii, the reaction continued to be positive for a period up to one year and a half after completion of the immunization.