Abstract
The cell-mediated immunity of 34 Ni contact dermatitis patients was evaluated by performing lymphocyte stimulations with NiSO4 (1.25 and 6.25 .mu.g/ml) and tuberculin (PPD = purified protein derivative), phytohemagglutinin-P, pokeweed mitogen and concanavalin A. Of the patients, 26 were nonatopic and 8 atopic. Healthy subjects (49) served as controls. NiSO4 stimulation was significantly increased (P < 0.005) in the allergic subjects, whereas PPD stimulation was decreased (P = 0.01). The responses to the other mitogens did not differ significantly between the control subjects and the patients. The lymphocyte transformation reaction to NiSO4 occurred in T [thymus-derived] cells and was enhanced by the helper function of macrophages.