Suppressor cell activity in a proliferative disorder of T lymphocytes

We report details of the immunological profile of a patient with the candidiasis endocrinopathy syndrome who has developed T-type chronic lymphocytic leukaemia. The patient is anergic to a panel of delayed hypersensitivity skin tests, and has poor in vitro mitogenic responses, but B cell function in vivo is not impaired. Subsequent functional studies have revealed that cells from the patient have a significant suppressive effect in coculture (P less than 0.05) on the responses of healthy donor lymphocytes (NR) to the mitogen phytohaemagglutinin (PHA). A degree of selectivity for the suppressive effect is suggested by the lack of similar effects on coculture responses to the mitogens concanavalin A (Con A) and pokeweed mitogen (PWM). Mitomycin C treatment of the patient's cells reduced their suppressive activity but significant suppression was still observed in the majority of PHA cocultures. The suppressor activity required the presence of the patient's cells in cocultures, as no suppression was observed when the patient's serum or cell culture supernatant were included instead of the patient's cells in NR cultures.