Extracorporeal photopheresis for bronchiolitis obliterans syndrome after allogeneic stem cell transplant: An emerging therapeutic approach?

Bronchiolitis obliterans syndrome (BOS) is the main manifestation of pulmonary GVHD. It has often a dramatic and fast evolution and current treatment (change or increase in immunosuppression, macrolides and inhaled therapy) is poor with high mortality rates. In this scenario, extracorporeal photopheresis (ECP) bursts as a new immunomodulatory approach with a different philosophical purpose. In fact, available data show that ECP treatment is intended to delay the inflammatory process and consequently respiratory lung function decline, rather than reverse the damage itself. Preliminary results reported in literature show that ECP may effectively improve/slow lung function decline in cGVHD patients with BOS after standard treatment failure. Further studies are needed to confirm the efficacy of ECP, assess the optimal schedule and consider it for early treatment.