The Complement-Fixation Test in Extracutaneous Sporotrichosis

SUMMARY

Sera from 18 patients with various forms of sporotrichosis were studied serologically. Of nine patients with active cutaneous disease during the study, six had negative complement-fixation (CF) tests, and three had titers of 1:8. Nine additional patients, eight of whom were culturally active during the study, had extracutaneous sporotrichosis. Seven of the patients with active extracutaneous sporotrichosis had titers of 1:16 or greater, whereas one had repeated titers of 1:8. The remaining patient had a negative CF test but was studied 3 months after the last positive culture and was considered to be inactive at that time.

Among 125 control patients, 78 of whom had active mycotic disease other than sporotrichosis, none had a positive CF test, whereas 20 had positive agar gel precipitin reactions.

Two patients had serial determinations during therapy, and both showed a significant decrease in CF titers, paralleling clinical improvement.

The CF test is effective in detecting extracutaneous sporotrichosis, whereas the agar gel precipitin test, as performed in our laboratory, is relatively nonspecific.

The CF test might also be used to follow the clinical response of patients during therapy.