Proteinuria following transplantation. Correlation with histopathology and outcome.

A review of 693 renal transplant recipients revealed 77 (11%) in whom persistent, heavy proteinuria (greater than 2 g/24 hr) developed. Renal histology was available in all 77 patients. Twenty-one patients had received kidneys from living-related donors, the remaining 56 from cadaveric donors. The cause of proteinuria in these 77 patients was as follows: transplant glomerulopathy (30), allograft glomerulonephritis (22), chronic rejection (21), renal vein thrombosis (2), diabetic glomerulosclerosis (1), and hypertensive nephrosclerosis (1). Of the 22 patients who developed glomerulonephritis in the transplanted kidney, 6 had recurrent disease (3--membranous glomerulopathy, 2--focal sclerosis and hyalinosis, 1--membranoproliferative glomerulonephritis); 6 developed de novo glomerulonephritis; and in 10 the type of glomerulonephritis could not be classified as recurrent or as de novo because of lack of characterization of the original kidney disease. Renal vein thrombosis occurred in association with other lesions in an additional 5 cases (3--chronic rejection; 2--membranous glomerulopathy). In follow-up only 23.4% (18 of 77) of the patients maintained prolonged graft function; the majority of grafts being lost within one year of the development of persistent, heavy proteinuria. Of the 18 patients who retained their grafts, 8 had glomerulonephritis, 5 transplant glomerulopathy, and 5 chronic rejection. This study confirms the poor prognosis that has been reported with the development of nephrotic-range proteinuria in renal allograft recipients.