術前DSAの有無によるプロトコール生検の有用性の検討

抄録

【Introduction】 Despite advancements in immunosuppressive therapies, long-term graft loss remains a significant concern following kidney transplantation. Protocol biopsies (PBs) are widely employed in clinically stable recipients to detect subclinical rejection, infections, calcineurin inhibitor (CNI) toxicity, and recurrent glomerulonephritis. However, PBs carry procedural risks, necessitating a careful evaluation of their clinical utility.

【Design and Methods】 This retrospective study analyzed 96 PBs from 32 kidney transplant recipients at a single center between January 2019 and February 2024. PBs were performed at 6 months, 1 year, and 2 years post-transplant in clinically stable patients. Episode biopsies were excluded. Histopathological findings and subsequent clinical interventions were assessed. Outcomes were compared between pre-transplant donor-specific antibody (DSA)-positive (n＝5) and DSA-negative (n＝27) patients.

【Results】 Histopathological abnormalities were identified in 36.5% of PBs, including 4.2% with rejection (2 chronic active antibody-mediated rejection and 2 chronic active T-cell-mediated rejection), all occurring in the DSA-positive group (p<0.01). CNI toxicity was observed in 21.9% of biopsies, with no significant difference by DSA status. Clinical interventions were initiated in 16.7% of cases, most commonly at 6 months (31.2%), and declined significantly by 2 years (0%; p<0.01). No rejections or interventions were noted in DSA-negative patients at 2 years.

【Conclusion】 PBs are valuable for identifying subclinical rejection, particularly in DSA-positive recipients. However, their utility in DSA-negative patients diminishes over time. Risk-stratified PB strategies, especially based on DSA status, may enhance clinical decision-making while minimizing unnecessary procedural risk.