HISTOPLASMIN-CYL, A YEAST PHASE REAGENT IN SKIN-TEST STUDIES WITH HUMANS

Abstract
A yeast phase histoplasmin, designated CYL [controlled yeast lysate], was studied in 156 humans living in areas of the USA endemic for histoplasmosis, coccidioidomycosis, or both fungal entities. Comparisons were made with Food and Drug Administration reference mycelial histoplasmin. Among persons without concurrent spherulin sensitivity, reactor rates and sizes were the same with both reagents. Some persons with spherulin sensitivity reacted only to the mycelial reagent. Histoplasmin-CYL skin tests did not induce significant changes in complement-fixing antibody in histoplasmin-reactive subjects.