THYMOMA WITH IMMUNODEFICIENCY (GOODS-SYNDROME) ASSOCIATED WITH SELECTIVE COBALAMIN MALABSORPTION AND BENIGN IGM-KAPPA GAMMOPATHY

We have described the first case, to our knowledge, in which recurrent respiratory tract infections were the primary manifestation of thymom a with immunodeficiency (Good's syndrome) associated with cobalamin ma labsorption and immunoglobulin M-kappa (IgM-kappa)M component. The int rinsic factor receptor activity was dramatically decreased in a mucosa l homogenate prepared from ileal biopsies. This decreased activity cou ld be the principal cause of the malabsorption of labelled cobalamin w hich was observed in the presence of intrinsic factor. However, it cou ld be the consequence of the cobalamin deficiency, as it is known that a cobalamin deficiency can affect the assimilation of cobalamin, even in presence of exogenous intrinsic factor.