Glomerulonephritis with microtubular deposits associated with cryoglobulinemia and chronic active hepatitis

A 65-year-old-woman presented with edema, ascites, proteinuria and abnormal liver function tests. A small amount of mixed cryoglobulin was detected in her serum. Liver biopsy revealed mild chronic active hepatitis, but tests for hepatotropic viral infection were negative. Electron microscopy of the renal biopsy revealed glomerular electron-dense deposits that contained numerous tubular structures. Renal amyloidosis and light chain deposition disease were ruled out by appropriate histological techniques. The ultrastructural findings of renal biopsy suggested either cryoglobulinemic glomerulonephritis or immunotactoid glomerulopathy. Although the exact interrelationship among the peculiar glomerulopathy, cryoglobulinemia and chronic active hepatitis in the present case remains undetermined, this report enlarges the spectrum of glomerulopathy characterized by extracellular deposition of microtubules.