Pleased to share a newly published research paper “Molecular diagnosis of T cell-mediated rejection in bronchial mucosal and transbronchial biopsies” in the American Journal of Transplantation Key findings:

15 October 2026

Key findings:

A safer approach to rejection diagnosis: Bronchial mucosal biopsies (3BMB) offer a potentially safer alternative to transbronchial biopsies (TBB), particularly in lung transplant recipients with compromised pulmonary function. Molecular analysis may overcome the absence of standardized histological rejection criteria for 3BMB.
Three distinct molecular phenotypes emerge: Transcriptomic analysis of 526 bronchial mucosal biopsies from 433 lung transplants identified three groups: no rejection (NR; n=387), T cell-mediated rejection (TCMR; n=109), and NK cell-rich rejection-like (NKRL; n=30).
Excellent cross-biopsy type concordance: Molecular TCMR identified in bronchial mucosal biopsies strongly predicted molecular TCMR in transbronchial biopsies, achieving an AUC of 0.99, indicating highly consistent rejection-associated molecular signals across biopsy types.
Molecular TCMR predicts adverse clinical outcomes: TCMR in bronchial mucosal biopsies was associated with chronic lung allograft dysfunction (CLAD) and increased graft loss, supporting the clinical relevance of the molecular classification.
Limited evidence for antibody-mediated rejection: Although NKRL biopsies exhibited mild molecular rejection features, they were not associated with donor-specific antibodies or established ISHLT criteria for antibody-mediated rejection. Overall, the findings support the potential use of bronchial mucosal biopsies for molecular diagnosis of TCMR.