Photobiomodulation Therapy Alleviates Tissue Fibroses Associated with Chronic Graft-Versus-Host Disease: Two Case Reports and Putative Anti-Fibrotic Roles of TGF-β

Objective: Patients who receive allogeneic hematopoietic stem cell transplantation may experience oral complications due to chronic graft-versus-host disease (cGVHD). The manifestations may include progressive sclerosis-like changes that may involve various body sites, including the oropharynx. Methods and results: We present two cGVHD cases of oropharyngeal fibrotic changes that affected functions that were treated with photobiomodulation (PBM) therapy. These case reports suggest that PBM therapy represents an additional, innovative approach affecting discrete phases in cGVHD-associated fibrotic changes. Conclusions: We discuss these observations in the context of currently understood molecular mechanisms, especially induction of transforming growth factor beta and NFκB that appear to be counter-intuitive to their known roles in matrix synthesis and inflammation that contribute to tissue fibroses. The clinical benefit noted in the two cases presented clearly indicates that there are distinct mechanistic and biological insights in the regulation of these molecular pathways in determining therapeutic efficacy with PBM therapy.