Surveillance Protocol Kidney Transplant Biopsies: Their Evolving Role in Clinical Practice

Abstract

Protocol renal allograft biopsies at fixed time points from transplantation have aided research and provided insights into the pathogenesis of early and late allograft injury. Their role is evolving from research to a clinical management tool needed to detect subclinical pathology requiring treatment adjustment. They frequently reveal unexpected findings and influence therapy in the majority of patients. Detection of subclinical rejection (SCR) remains important despite declining prevalence with triple therapy, the evidence favors treatment, if found. Surveillance biopsies in steroid avoidance and calcineurin inhibitor (CNI) withdrawal programs provide an important safety net against the increased rates of late acute and SCR. Individualization of therapy in high-risk patients and safe reduction of immunosuppression in standard risk individuals becomes possible. Other potentially reversible chronic pathologies that may be detected, include chronic Tcell or antibody-mediated rejection, recurrent disease, BK virus-associated nephropathy, interstitial fibrosis and tubular atrophy and CNI nephrotoxicity, allowing modifications of therapy to limit ongoing graft injury. Biopsy is safe and inexpensive compared with costs of earlier graft failure and return to dialysis. This review summarizes current evidence on use of surveillance histology for the clinical practice of renal transplantation.

Proteinuria as a Noninvasive Marker for Renal Allograft Histology and Failure

“…In specific populations, for example, high-risk patients with cross-match-positive transplantation, with de novo DSA, or at high risk of glomerular disease recurrence, surveillance biopsies could thus be warranted in the absence of proteinuria or graft dysfunction, for the timely detection of subclinical injury. 22 In this light, it seems surprising that the presence or occurrence of DSA did not independently associate with proteinuria in our study, which is in agreement with two recent studies. 23,24 Although the number of patients positive for DSA was low in our cohort and the data should thus be interpreted cautiously, it could be hypothesized that the presence of DSA does not lead to proteinuria per se, but that proteinuria appears only if DSA cause glomerular injury.…”

Detection of Clinical and Subclinical Tubulo-Interstitial Inflammation by the Urinary CXCL10 Chemokine in a Real-Life Setting

“…clinical allograft rejection) decreased to 10-15% using tacrolimusbased immunosuppression (2), subclinical rejection including borderline changes occurs in 10-30% of patients within the first year posttransplant (3)(4)(5)(6). As persisting subclinical rejection is associated with progression to chronic irreversible damage and slow deterioration of allograft function (5,(7)(8)(9), its detection is important allowing for timely therapeutic interventions (10).…”

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“…10 Other authors have suggested the use of biopsies to detect subclinical rejection. 11,12 A total of 61 biopsies were analyzed and the following oxidative stress enzymes were detected by Western blot: catalase (60 kilodaltons), MnSoD (25 kilodaltons), CuZnSoD (23 kilodaltons), thioredoxin reductase (55 kilodaltons), thioredoxin (2b1) (12 kilodaltons), and thioredoxin (62 kilodaltons).…”