IgG Antibodies in Leprosy and Their Relation to Thl/Th2 Responses

Abstract

The study of the IgG subclasses of antibodies across the clinical spectrum of leprosy id not reveal differences that could be related to the Th1/Th2 dichotomy; the predominance of antibodies of the IgG1, 2 and 3 subclasses suggest a possible Th1 response across the spectrum in Venezuelan patients. In contrast, the anergic form of American cutaneous leishmaniasis was characterized by a strong IgG4 specific antibody response, suggesting a Th2 response, while localized forms of the disease appeared to be associated with responses of the Th1 type. Persisting antibodies to phenolic glyco- lipid-I in a small percentage of clinically inactive multibacillary patients may reflect differences in the catabolism of this unusual antigen, since persistence was not associated with a unique initial IgG subclass response to a complex extract of Mycobacterium leprae antigens.