Monitoring lung function in patients with chronic graft versus host disease: a pilot study

Bronchiolitis obliterans syndrome (BOS) following allogenic haematopoietic stem cell transplant is considered the manifestation of chronic graft versus host disease (cGvHD) in the lung, and affects about 14% of patients with cGvHD, mainly in the first 2 years after transplant. Despite advances in assessment, diagnosis and treatment, the clinical prognosis remains poor for patients with pulmonary manifestations of cGvHD. A pilot study of 50 patients was devised to establish whether a relationship exists between forced expiratory volume in 1 second (FEV1) via pulmonary function test (PFT) and the equivalent peak expiratory flow (PEF) via peak flow handheld spirometry in cGvHD patients receiving extracorporeal photopheresis (ECP). Only PEF observed within 2 days of PFT could be compared with data at month 3, 6, 9 and 12. This pilot study illustrated that monitoring via handheld peak flow readings has the potential to become an acceptable method of monitoring lung function longitudinally in cGvHD patients.