Lung allograft standardized histological analysis (LASHA) template: A research consensus proposal

Background: Routine monitoring of lung-transplanted patients is crucial for the identification of immunological and non-immunological complications. Determining the etiology of acute allograft dysfunction, particularly in alloimmune-mediated disorders, relies heavily on the lung biopsy with histopathologic analysis. Standardization of the pathologic diagnosis of rejection (e.g., cellular and antibody-mediated) is based on consensus statements and guidelines, indicating the importance of a multidisciplinary approach to achieve a definitive etiological diagnosis. In addition to these statements and guidelines, refinements and standardizations are feasible through systematic analysis morphological, immunophenotypic and molecular alterations observed in transbronchial biopsies. This study is to identify key morphologic features to be assessed, select consistent and reproducible terminology for each histological feature, and provide standardized definitions for pathological assessment and grading. Methods: A template was created by experts in lung transplantation including pathologists, pulmonologists, immunologists. An initial draft was circulated, followed by discussions and multiple revisions by email and conference calls. Results: The “lung allograft standardized histological analysis – LASHA” template was created and structured as multiple-choice questions with number of fields to be filled in to allow for standardization of results and easy transfer into a future electronic spreadsheet. Conclusion: This template will help facilitate multicenter studies through a uniform protocol and correlations with new diagnostic modalities. After validation in large-scale studies, an optimized template could be included in routine clinical practice to enhance graft assessment and medical decision-making.