[Glomerular IgA deposits in an autopsy study]

One hundred kidneys from 100 non-selected autopsy cases without any overt renal disease were examined by immunofluorescence to reveal the incidences and features of cases with clinically latent glomerular IgA deposits. Glomerular IgA deposits were found in 10 cases (10.0%), consisting of 4 with liver cirrhosis and 6 with other diseases. IgA deposition was observed in 4 of 13 cirrhotic patients (30.8%), 3 of 15 patients with gastrointestinal carcinoma (20.0%), one of 11 patients with cardiovascular disease (9.1%), one of 3 patients with fulminant hepatitis (33.3%), and one of 21 patients with broncho-pulmonary disease (4.8%). Light microscopy showed minor glomerular abnormalities in all non-cirrhotic cases with IgA deposits except in one case. By contrast, variable significant glomerular lesions were found in the cirrhotic cases with IgA deposits, for example mesangial proliferation and circumferential mesangial inter-position. Excluding 13 cases with liver cirrhosis, the results of urinalysis at the time of admission were available for the study in 55 of 87 cases. Forty-four of 55 cases showed normal urinalysis. Glomerular IgA deposition was found in 4 cases (9.1%) of 44 with normal urinalysis. It may be said that IgA deposition without clinical evidence of nephropathy occurred even in a normal population with an incidence of about 10%.