P1657GRAFT- AND PATIENT-SURVIVAL IN TRANSPLANT KIDNEY PATIENTS UNDERGOING TRANSPLANT BIOPSIES

Abstract

Abstract Background and Aims Kidney transplantation is a frequent treatment in uremic patients. However, long term patency is limited. The aim of this study was to investigate the histological findings in transplant biopsies in relation to clinical outcome in patients. Method 1542 patients (36.4 % women) were included if they had a first kidney transplant registered in a quality assessment registry (period October 24, 1968 and August 28, 2017) and also had registered a first transplant kidney biopsy during the period January 1, 2007 until Mars 2, 2018. Graft- and patient-survival analysis was performed by Kaplan-Meier- and Cox-regression-analysis (adjusted for age and gender). Data are presented as Hazard Ratio (HR) and 95% Confidence Intervals (CI). A two-sided p-value of <0.05 was considered as statistically significant. Results Patients with primary and recurrent glomerulonephritis (GN) found in the biopsy had a worse graft- (70% at 5-year) and patient-survival (85% at 5-year) compared to all other diagnoses (p<0.05). Comparing with GN as reference group with respect to graft-loss the risk was lower if biopsies revealed infections (HR 0.3, CI 0.1-0.9), chronic damages (HR 0.38, CI 0.2-0.6), CNI-toxicity (HR 0.3, CI 0.2-0.6) or rejection (HR 0.5, CI 0.3-0.9). Looking at patient-survival, compared to those with GN a lower risk for early death was found for those with tubulointerstitial diseases (HR 0.35, CI 0.1-0.9), chronic damages (HR 0.35, CI 0.2-0.7), CNI-toxicity (HR 0.4, CI 0.2-0.9) and rejection (HR 0.4, CI 0.2-0.9) while those with hematological diseases (HR 14, CI 3.7-53.6) had higher risk for early death. Comparing subgroups within rejections, there was a significant (p<0.01) better graft-survival in patients with cellular rejection or borderline changes (90% at 5-year) versus those with humoral (65% at 5-year), chronic humoral and cellular rejection (60% at 5-year), and transplant-glomerulopathy (TGP) (70% at 5-year). The patient-survival was worse for patients with a TGP (70% at 5-year) compared to cellular rejections (p=0.04). Patients with humoral (HR 4.4, CI 2.3-8.4), chronic humoral and cellular rejection (HR 5.8, CI 2.9-9.9) and TGP (HR 3.7, CI 1.6-8.8) had higher risk for graft-loss and patients with TGP (HR 3.5, CI 1.2-10.5) had higher risk for early death compared to cellular rejection as reference. In addition, it was found that the median time between the graft-loss and death (25 patients) was 76 days (mean 304 days) and 44% of these patients died within 30 days after graft-loss. The median age of these patients was 62 years. Between the patients who died within 30 days and the others, no differences were found in cause of death, findings in the transplant kidney biopsies or type of transplant kidney (living versus deceased). Conclusion Patients with GN and patients with TGP had a worse outcome in both graft- and patient-survival. Awareness should focus on the patients who die soon after graft-loss.