Physical function after lung transplantation for late-onset noninfectious pulmonary complications after allogeneic hematopoietic stem cell transplantation

Purpose Late-onset noninfectious pulmonary complications (LONIPCs) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are fatal, and lung transplantation is the only curative treatment. Although lung transplantation for LONIPCs may confer good survival rates, it is unclear whether or how impaired physical functioning is restored. Thus, this study aimed to investigate the long-term course and associated changes in physical functions after lung transplantation in patients with LONIPCs after allo-HSCT. Methods This prospective cohort study enrolled 15 patients who received lung transplantation for LONIPCs after allo-HSCT between 2012 and 2018. Dyspnea scores, performance status, physical function, and exercise tolerance were assessed before lung transplantation and up to 2 years after transplantation. Results Two years after lung transplantation, the dyspnea scores and performance status improved, but did not recover completely. Physical function was assessed using the knee extensor strength (KES) and 6-min walk test (6MWT); the results were poor until 3 months after transplantation but improved over 2 years. The 6MWT distance showed improvement to a nearly healthy level (562.7 m). Recovery of exercise tolerance was associated with recovery in % vital capacity (%VC; r=0.5) and KES (r=0.4) from 3 months to 2 years after lung transplantation. Furthermore, a flat thorax, which is a characteristic of patients with LONIPCs, affected the %VC at 2 years after transplantation (r=0.8). Conclusion Lung transplantation for LONIPCs may restore impaired physical function. A multifaceted rehabilitation program should be considered, especially to improve muscle weakness and pulmonary function.