Atopy and IgE in patients with leprosy.
The atopic status of patients with leprosy was assessed by medical history, physical examination, serum total IgE, and specific IgE antibodies to common allergens (by skin testing and RAST). Tests for specific IgE antibody to Mycobacterium leprae were performed by RAST and immunoblotting technique. We studied 28 patients with leprosy and 49 control subjects. The two groups did not differ significantly in the prevalence of atopic disease. The IgE level was significantly higher in the patients, however, than in the control subjects, whether there was atopy (296.1 versus 96.3 IU/ml) or not atopy (72.9 versus 18.9 IU/ml). Neither RAST nor immunoblotting technique detected significant levels of IgE antibodies to M. leprae. Our data indicate that leprosy was associated with increased total IgE level, but clinical atopy in patients with leprosy was similar to that in control subjects. The observed IgE increase in patients with leprosy appears to be generally nonspecific.