Two-Week Protocol Biopsy in Renal Allograft: Feasibility, Safety, and Outcomes

Abstract

Background: Protocol biopsy in renal allograft helps to early detect subclinical rejection (SCR) in patients who have no abnormal clinical and laboratory findings. Still, there are rare reports about the techniques and outcomes of two-week protocol biopsy. The aim of this study was to assess two-week protocol biopsy regarding the technical feasibility, procedure safety, and clinical outcomes. Methods: A total of 894 protocol biopsies were performed in adult recipients between 2012 and 2019. Two-week and one-year protocol biopsies were guided with ultrasound in 842 and 399 patients by one of four radiologists with wide range of biopsy experience, respectively. These protocol biopsies were compared in terms of feasibility and safety. Standard references were clinico-laboratory findings and biopsy examinations. Results: The median period of two-week and one-year protocol biopsies were 12 days (10–20 days) and 383 days (302–420 days), respectively. All protocol biopsies were technically successful and there was no difference between radiologists regarding technical success and complications (p = 0.453). Major complication (Clavien–Dindo grading II-IV) rates of two-week and one-year protocol biopsies were 0.3% (3/842) and 0.2% (1/399), respectively (p = 1.000). However, univariate analysis demonstrated that platelet count <100 K/mL and blood urea nitrogen ≥40 mg/dL were associated with major complications in two-week protocol biopsy. The SCRs of these protocol biopsies were 15.4% (130/842) and 33.6% (134/399), respectively (p < 0.001). Conclusion: Two-week protocol biopsy is technically feasible and safe. It contributes to early detecting a substantial number of SCRs. Prior to the biopsy, platelet count and blood urea nitrogen should be carefully checked to predict major complications.

Effects of Treating Subclinical Rejection 2 Weeks after Kidney Transplantation, as Determined by Analyzing 1-Year Histologic Outcomes

“…From 2012 to 2019, the major complication rate from PB among 1,438 KT recipients at Samsung Medical Center was 0.45% (4/882) at the 2-week PB and 0.17% (1/556) at the 1-year PB. [30] In the population of this study, no complications requiring intervention occurred after biopsy. This is not different from previous studies, so complications should probably not cause hesitation in applying a PB strategy.…”

Prediction of very early subclinical rejection with machine learning in kidney transplantation

“…All biopsy cores were obtained by two week protocol biopsy and assessed using Banff 2007 classification. The procedure details of protocol biopsy were described on a previous reported paper 11 . If borderline rejection was observed in the protocol biopsy, repeated biopsy was not performed, and steroid pulse therapy was administered.…”

“…For maintenance, all patients were treated with a triple immunosuppressive regimen (tacrolimus, myophenolate mofetil, and methylprednisolone). The details of maintenance protocol were described in a previously reported paper 11 .…”

“…Previously, our research team reported the safety and feasibility of performing protocol biopsies at the 2-week 11 . However, protocol biopsy still presents several limitations, including the risk of complications such as bleeding, cost concerns, and challenges in implementation across different centers 12 , 13 .…”

“…The purpose of this study is to analyze the incidence and risk factors of early SCR based on 2-week protocol biopsy data accumulated in our center 11 , and to suggest indications for protocol biopsy. In addition, using both machine learning and logistic regression, we develop risk assessment models of SCR and compare performances.…”