Clinical and Pathologic Feature of Patients With Early Versus Late Active Antibody-Mediated Rejection After Kidney Transplantation: A Single-Center Experience.

Abstract

OBJECTIVE\nActive antibody-mediated rejection (aABMR), particularly late aABMR, remains a major challenge for long-term renal allograft survival. This single-center retrospective study aimed to compare clinical features between early vs late aABMR and to identify risk factors for allograft failure among patients with aABMR.\n\n\nMETHOD\nForty-one patients diagnosed with aABMR at our hospital were included and were divided into 2 groups: early aABMR (≤6 months; n\xa0= 10) vs late aABMR (>6 months; n\xa0= 31) based on the time from transplant to diagnosis. Their clinical and pathologic data were compared. This study was performed in compliance with the Helsinki Congress and the Declaration of Istanbul.\n\n\nRESULTS\nOf 10 patients with early aABMR, none had allograft failure, whereas 8 of 31 patients with late aABMR had developed allograft failure at the time of follow-up (25.8%). At the time of biopsy, patients with early aABMR had higher positive grade in urine occult blood test than patients with late aABMR (P\xa0= .01); however, the late aABMR group displayed more intensive interstitial fibrosis and tubular atrophy (P\xa0= .03) and more frequent HLA-DQ-type donor-specific antibodies. Interestingly, donor-specific antibody conversion from positive to negative was not associated with C4d grade but was correlated with time from transplant to biopsy. Multivariate Cox regression analysis indicated that high levels of serum creatinine or proteinuria and concomitant T-cell-mediated rejection were independent risk factors for allograft failure in patients with aABMR.\n\n\nCONCLUSION\nThese data not only confirm that early aABMR has better clinical outcomes than late aABMR but highlight the importance of early diagnostic biopsy and early therapeutic interventions in ABMR, particularly in patients with high levels of serum creatinine or proteinuria in the early posttransplant phase.