Sarcoidosis complicated with IgA nephropathy.

Though IgA nephropathy (IgAN) and sarcoidosis have been reported simultaneously in patients occasionally, it remains controversial whether there is any association between the two. In this report we describe our experience with one definite and two subclinical cases of IgAN diagnosed during the clinical course of sarcoidosis. Our findings suggest a possible association between these disorders, and a higher incidence of subclinical IgAN among sarcoidosis patients than among the general population. We also discuss the common immunological background shared by these two diseases.