Confirmation of tonsillar anomalies in IgA nephropathy: a multicenter study.

Tonsillar abnormalities have previously been evidenced in IgA nephropathy (IgAN). We report the results of a systematic quantitative analysis of 303 tonsils obtained in 70 IgAN patients and 142 controls. IgG- and IgA-producing plasma cells, stained by immunofluorescence, were enumerated on serial sections of all samples. Both the percentage and number of IgA+ cells were significantly increased in IgAN patients. This anomaly was also observed in age- or sex-matched subgroups of patients. Performed on a large series of individuals this study confirms the dysregulation of IgA production the upper respiratory tract of IgAN patients.