Does the antibody mediated rejection grading scale have prognostic prediction? Yes, but the picture is still blurry

Abstract

Purpose of reviewAntibody-mediated rejection (ABMR) is a condition difficult to diagnose and treat, which may significantly impair the outcome of heart transplant recipients. In clinical practice, diagnosis is based on immunopathology grading of endomyocardial biopsies (EMB). Despite its value, the current diagnostic system has several pitfalls that have been addressed in recent literature. Recent findingsPathology grading of ABMR (pAMR) has a relevant prognostic factor. However, it does not capture several nuances, such as chronic vs. acute ABMR, mixed rejection or microvascular inflammation. Molecular biology-based assays are shedding new light on the mechanisms of ABMR, which could improve the precision of ABMR diagnosis.

Complement blockade with eculizumab to treat acute symptomatic humoral rejection after heart transplantation

“…In our case, EMB was pAMR2, which we have previously shown to be more likely associated with DSA and overt graft dysfunction than pAMR1 3 . Nevertheless, the pAMR grading system is only modestly correlated to the outcome, with similar cardiovascular mortality among pAMR1 H+, pAMR1 I+, and pAMR2 patients, 20 and it does not provide definite guidance for patient management per se 21 . In fact, the natural history of AMR is more predicted by its clinical phenotype, and treatment recommendations are mainly based on the occurrence of concomitant graft dysfunction whatever underlying pAMR grade 2 …”

“…3 Nevertheless, the pAMR grading system is only modestly correlated to the outcome, with similar cardiovascular mortality among pAMR1 H+, pAMR1 I+, and pAMR2 patients, 20 and it does not provide definite guidance for patient management per se. 21 In fact, the natural history of AMR is more predicted by its clinical phenotype, and treatment recommendations are mainly based on the occurrence of concomitant graft dysfunction whatever underlying pAMR grade. 2 Actually, the clinical presentation of cardiac AMR ranges from asymptomatic detection on routine EMB to severe allograft dysfunction and cardiogenic shock despite a seemingly similar appearance on EMB.…”