Evaluation of Protocol Biopsy Utility 12 Months after Renal Transplantation : A Multicenter Observational Analysis

Abstract EN

The clinical merit of surveillance kidney graft biopsies remains controversial.

A retrospective, multicenter analysis evaluated 12-month surveillance biopsies (SB, 154 patients) versus no SB (NSB, 138 patients (11 with diagnostic biopsy)) in patients >18 months posttransplant with estimated GFR (eGFR) ≥30 mL/min.

The primary objective was to describe renal function at 18 months post-transplant in patients with or without SB at month 12.

Globally, most recipients in both cohorts were at low immunological risk (<10% of patients with PRA ≥30%).

The immunosuppressive regimen remained unchanged following more than half of SB that exhibited chronic lesions (18/33, 54.5%).

Mean (SD) eGFR at month 18 (primary endpoint) was 56 (19) mL/min/1.73 m² with SB and 54 (15) mL/min/1.73 m² with NSB (P=0.48).

In the SB group, slight nonspecific changes were observed in 51 cases, rejection (acute or chronic) in 6 cases, CNI-related toxicity in 15 cases, recurrence of initial disease in two cases, and interstitial fibrosis/tubular atrophy (IF/TA) in 83 cases (71.6%), of which 35 cases (30.2%) were grade II/III lesions.

eGFR <50 mL/min/1.73 m² at month 6 predicted IF/TA grade II or III (OR 3.85, 95% CI 1.64, 9.05, P<0.002).

SB at 12 months posttransplant did not prompt significant modification of immunosuppression, and no renal benefit was observed.