Lymphocyte function in relapsed pulmonary blastomycosis.

Lymphocyte function was studied in two patients with multiple relapses of pulmonary blastomycosis following antifungal therapy. Neither patient was anergic to routine delayed hypersensitivity skin testing with common antigens. Both had normal in vitro lymphocyte transformation responses to standard mitogens and common microbial antigens. The ability of lymphocytes from the two patients to respond to antigens of the infecting organism was evaluated using a yeast phase Blastomyces dermatitidis extract in tests of in vitro lymphocyte function. Both patients demonstrated positive responses to this extract in standard assays of two in vitro parameters of lymphocyte function, lymphocyte transformation, and lymphokine production. Therefore if an immunologic defect is responsible for the repeated relapses of treated pulmonary blastomycosis in these two patients, it apparently is not one of deficient lymphocyte responsiveness against the infecting organism, as has been found using similar techniques in patients with disseminated deep infections caused by other fungal organisms.