B cell-mediated immune reconstitution after lung transplantation: mechanisms, interventions, and prognostic evaluation.

Lung transplantation remains a life-saving option for patients with end-stage lung disease, yet long-term outcomes remain limited by chronic rejection and infection. Although T cells have historically been the focus of transplant immunology, B cells are now recognized as critical regulators of immune responses through the production of antibodies, antigen presentation, and cytokine secretion. These functions contribute to both protective immunity and antibody-mediated rejection (AMR), particularly in the form of donor-specific antibodies (DSAs), which drive chronic lung allograft dysfunction (CLAD). B cell dysregulation can result from ischemia-reperfusion injury (IRI), infection, and immunosuppressive agents such as tacrolimus (TAC), with distinct effects emerging across perioperative and late post-transplant phases. Advances in single-cell RNA sequencing and B cell receptor (BCR) repertoire profiling have enabled precise characterization of B cell dynamics, offering new opportunities for stratified immune monitoring and risk prediction. This review summarizes B cell biology in lung transplantation, outlines stage-specific perturbations, and explores how multi-omics technologies may support personalized immunomodulation and prognostic assessment.