The relationship between histopathological findings and clinical follow-up of kidney transplant recipients underwent allograft biopsy in 2009-2013 in Mediterranean University Hospital Organ Transplant Center

Nowadays, kidney transplantation is considered to be the most outstanding treatment method for end-stage renal failure (ESRF). By comparison with hemodialysis or peritoneal dialysis kidney transplantion is a method replacing kidney?s other functions (in endocrine, hematologic, and calcium and bone metabolism) in body. Renal biopsy is accurate diagnostic tool for histopathological diagnosis. In this retrospective study, we aimed to clarify the reason of the high creatinine levels and proteinuria in kidney transplant recipients undergoing allograft biopsy and to evaluate the results of the biopsies when considered rejection and to investigate the distribution of diagnoses (humoral or cellular rejections, post-transplant recurrent glomerulonephritis, drug toxicity, BK virus infection, acute tubular necrosis) in our patients. 92 patients were biopsied. 24 of them were female and 68 were male. Mean age at transplant was 30.4 year. According to the source of donor 81 were living, 11 were cadaveric kidney transplantation. Biopsies were performed at least 4 days at most 155 months after transplantation. Histopathological examination of biopsies showed 20 borderline changes (suspected acute T-cell mediated rejection), 2 acute antibody-mediated rejection, 10 chronic active antibody-mediated rejection, 7 acute T-cell-mediated rejection, 8 recurrence of the primary disease or de novo glomerulonephritis, 1 coagulation necrosis, 9 tubular atrophy and interstitial fibrosis with varying degrees, 6 calcineurin inhibitor drug toxicity and 7 BK nephropathy. Average creatinine was 2.58±1.1 mg/dl. Proteinuria values during biopsy were 83-12600 mg/day and average proteinuria value were between 2142±2619 mg/day. Among the renal biopsy indications 39 patients had rapid deterioration of graft function, 27 patients had slow deterioration of graft function, 25 patients had proteinuria and just one had primary non-function. Proteinuria less than 1000 mg/day there were 2 biopsies with acute antibody-mediated rejection, 3 chronic active antibody-mediated rejection, 21 acute T cell mediated rejection-borderline, 7 chronic active T cell-mediated rejection and in the other group there were 12 biopsies. Proteinuria between 1000-3500 mg/day there were 5 chronic active antibody-mediated rejection, 2 acute T cell mediated rejection-borderline, 5 chronic active T cell-mediated rejection and in the other group there were 11 biopsies. Proteinuria over 3500 mg/day there were 2 chronic active antibody-mediated rejection, 4 acute T cell mediated rejection-borderline, 8 chronic active T cell mediated rejection and in the other group there were 7 biopsies. Without loss of patients 31 graft loss was seen in 92 patients. Patients when grouped as rejection, non rejection and BK nephropathy for proteinuria, there was statistically significant difference between groups, non-rejection group?s proteinuria were found to be higher than the BK nephropathy group?s. Glomerulitis, interstitial inflammation, arterial hyalinization, chronic glomerular changes, the presence of mesangial matrix, interstitial fibrosis and tubular atrophy was found to be correlated with the age of the biopsy. In chronic rejection group, proteinuria was higher than both acute rejection and BK nephropathy group. Banff scores of all biopsies were performed. Transplant glomerulopathy was found in 56 patients. TG were in 22 chronic active T cell and in 10 chronic active antibody-mediated rejection and were also in some patients in borderline changes, drug toxicity, BK nephropathy, IgA and IF/TA diagnosed as primer diagnosis. This is a retrospective trial to assess the results of renal allograft biopsies in our center. Due to the retrospective trial, we could not reach all of the patients?data. Although there were some of the lost data in some assessment, this study was intended to serve as a basis for future work