Home Spirometry Telemonitoring for Early Detection of Bronchiolitis Obliterans Syndrome in Patients with Chronic Graft-versus-Host Disease

Early detection of bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic cell transplantation (HCT) depends on recognition of subclinical spirometric changes, which is possible only with frequent interval spirometry. We evaluated the feasibility of home monitoring of weekly spirometry via a wireless handheld device and a web monitoring portal in a cohort of high-risk patients for the detection of lung function changes preceding BOS diagnosis. In this observational study, 46 patients with chronic graft-versus-host disease or a decline in forced expiratory volume in 1 second (FEV₁) of unclear etiology after allogeneic HCT were enrolled to perform weekly home spirometry with a wireless portable spirometer for a period of 1 year. Measurements were transmitted wirelessly to a Cloud-based monitoring portal. Feasibility evaluation included adherence with study procedures and an assessment of the home spirometry measurements compared with laboratory pulmonary function tests. Thirty-six patients (78%) completed 1 year of weekly monitoring. Overall adherence with weekly home spirometry measurements was 72% (interquartile range, 47% to 90%), which did not meet the predetermined threshold of 75% for high adherence. Correlation of home FEV₁ with laboratory FEV₁ was high, with a bias of 0.123 L (lower limit, -0.294 L; upper limit, 0.541 L), which is within acceptable limits for reliability. Of the 12 patients who were diagnosed with BOS or suspected BOS during the study period, 9 had an antecedent FEV₁ decline detected by home spirometry. Our data indicate that wireless handheld spirometry performed at home in a high-risk HCT cohort is feasible for close monitoring of pulmonary function and appears to facilitate early detection of BOS.