Clinicopathological analysis of glomerulopathy with fibronectin deposits (GFND): a case of sporadic, elderly-onset GFND with codeposition of IgA, C1q, and fibrinogen.

A 67-year-old Japanese man with recurrent nephrotic syndrome and impaired kidney function had a sporadic, elderly-onset case of glomerulopathy with fibronectin deposits. The daily urinary protein, serum albumin, blood urea nitrogen, and creatinine levels were 3.6 g/day, 2.7 g/dL, 19.5 mg/dL, and 1.70 mg/dL, respectively. Kidney biopsy samples were evaluated using electron microscopy and demonstrated membranoproliferative glomerulonephritis-like lesions with massive subendothelial depositions and no fibrillary structures. Immunofluorescent studies showed 1+ staining for IgA, C1q, and fibrinogen. Anti-fibronectin immunostaining demonstrated that the subendothelial deposits were positive for fibronectin. The administration of prednisolone and mizoribine improved the nephrotic syndrome.