[Management of chronic pulmonary GVH in 2025, indication for lung transplantation (SFGM-TC)]

The pulmonary form of graft-versus-host disease (GvHD) manifests as fibrotic damage to the bronchi (bronchiolitis obliterans syndrome [BOS]) or parenchyma (interstitial lung disease). It affects between 5 and 10% of allogeneic transplant patients and its prognosis remains uncertain. During this sixteenth session of the workshops on harmonizing practices in allogeneic transplantation, we reviewed the definitions and diagnostic criteria for pulmonary GvHD, discussed the various treatments available and the role of lung transplantation. We emphasized the inadequacy of the currently recognized diagnostic criteria and the need to revise them for earlier detection of BOS. We reviewed the recommendations for functional follow-up after allogeneic transplantation. New treatments have been developed for GvHD: Janus kinase inhibitors (ruxolitinib), rhokinase inhibitors (belumosudil) and anti-CSF1R antibody (axatilimab). Their efficacy in pulmonary GvHD is difficult to determine due to a lack of studies focusing on respiratory function. We discussed their place in relation to inhaled treatments, systemic corticosteroids, and extracorporeal photopheresis. Lung transplantation is an option to consider in severe cases that are refractory to treatment. Allogeneic transplant recipients represent a small proportion of lung transplant patients, even though the results are the same as for other indications. We reviewed the conditions under which a patient with pulmonary GVHD should be referred to a center with expertise in lung transplantation.