Membranous nephropathy transplanted in the donor kidney: observations of resolving glomerulopathy in serial allograft biopsies

We report a case of idiopathic, PLA2R-negative membranous nephropathy (MN) transplanted via a deceased donor kidney. Changes in glomerular immune deposits were followed in serial biopsies. The allograft recipient had end-stage disease without significant proteinuria from ischemic nephropathy due to chronic heart failure, hypertension, atherosclerosis and presumed diabetic nephropathy. Combined cardiac and renal transplants were performed. Maintenance immunosuppression consisted of prednisone, a calcineurin inhibitor and mycophenolate mofetil. MN was identified in the pre-implantation biopsy of the donor kidney. The recipient never developed significant proteinuria and there was no identifiable impact on graft function. Serial biopsies performed at Days 0, 18, 150, 234 and 812 revealed mild effacement of podocyte foot processes, progressive change from Ehrenreich-Churg Stage III-IV lesions of MN to segmental resolution by electron microscopy, and progressive decrease of IgG staining by immunofluorescence. The findings provide a novel observation of the protracted process of glomerular immune deposit resolution in healing MN transplanted in a neutral host environment.