Histological diagnosis from kidney transplant biopsy can contribute to prediction of graft survival.

Aim: The primary aim of this study was to in depth examine if the histological findings in a transplanted kidney biopsy can predict the prognosis for the graft and the patient. The secondary aim was to extend knowledge of the impact of time elapsed on biopsy findings.

Methods: Data from 1462 patients were merged from a kidney transplantation registry and a biopsy registry during 1 January 2007 and 30 September 2017. Kaplan-Meier analysis and multivariate Cox-regression analysis were performed and hazard ratios (HR) with 95% confidence intervals (CI) were presented.

Results: Compared to normal biopsy findings, graft survival after biopsy (gsaBiopsy) was shorter for patients with glomerular diseases (HR 8.2, CI:3.2-21.1), rejections (HR 4.2, CI:1.7-10.3), chronic changes including IFTA (HR 3.2, CI:1.3-8.0), acute tubular injuries (HR 3.0, CI:1.2-7.8), and borderline changes (HR 2.9, CI:1.1-7.6). Sub-analysis of rejections showed shorter gsaBiopsy for chronic TCMR (HR 4.7, CI:1.9-11.3), active ABMR (HR 3.6, CI:1.7-7.7) and chronic ABMR (HR 3.5, CI:2.0-6.0). Patients with TCMR Banff grade II (HR 0.35, CI:0.20-0.63) and grade I (HR 0.52, CI:0.29-0.93) had a better gsaBiopsy compared to all other types of rejections.

Conclusion: Shorter gsaBiopsy was noted in kidneys with glomerular diseases, rejections, acute tubular injuries and borderline changes. TCMR Banff rejections grade I and II were associated with a better prognosis.