Concomitant Fibronectin Glomerulopathy and Chronic Active Antibody-mediated Rejection in a Renal Allograft: A Case...

Fibronectin glomerulopathy (FNG) is a rare autosomal dominant glomerulonephritis characterized by proteinuria, hematuria, and progressive kidney dysfunction. FNG treatment includes kidney transplantation; however, chronic active antibody-mediated rejection (cABMR) poses a threat to the long-term survival of kidney allografts. Here, we report a case of FNG in a kidney allograft with cABMR.

A 51-year-old male underwent living-related kidney transplantation in March 2020 for end-stage kidney disease caused by diabetic nephropathy. Three years after kidney transplantation, he presented with 2+ proteinuria, hematuria, and progressive worsening of kidney allograft function, for which an allograft biopsy was performed. Histopathological examination revealed glomerular lobulation, glomerular duplication, peritubular capillaritis, and glomerulitis, which was consistent with cABMR. Immunohistochemistry revealed strong staining for fibronectin in the glomeruli, thus suggesting FNG. The patient was administered rituximab, plasma exchange, and intravenous glucocorticoids. However, these treatments have not yet achieved ideal effects.

We report a rare case of FGN with cABMR in a kidney allograft that was unresponsive to treatments. This case highlights the need for physicians that perform kidney transplants to familiarize themselves with these rare diseases. Moreover, timely kidney biopsy can help with the diagnosis.