Objective: To analyze the clinical feature, cause, treatment and outcome of late onset non-infectious pulmonary complications (LONIPC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).
Methods: The clinical data of 17 patients with malignant hematological diseases who survived for at least 3 months and suffered from LONIPC after allo-HSCT were retrospectively analyzed.
Results: The incidence of LONIPC was 17.7% in allo-HSCT recipients. The median of onset of respiratory symptoms was 6.5 months (3-13.5 months). Seven patients came down with LONIPC during fast tapering of cyclosporine A prophylaxis and 15 patients had already chronic graft versus host disease (cGVHD) before the occurrence of respiratory symptoms. The initial symptoms were non-productive cough and dyspnoea in all patients; five of them had low grade or moderate fever. CT scans revealed patchy ground-glass opacities, irregular patchy consolidation, band-like opacities, and micronodular densities. Histological examination of transbronchial biopsy showed infiltration of lymphocyte and monocytes in interstitium, peribronchiolar fibrosis and alveoli pulmonis obliteration. The response rate of corticosteroids in addition to cyclosporine therapy was 70.6%. Treatment beginning at the early stage was more effective than that beginning late. The mortality rate of LONIPC was 35.3%. Chest CT scanning showed lung fibrosis in the patients with protracted LONIPC.
Conclusion: The clinical manifestations and radiological changes of LONIPC are non-specific. The diagnosis is made by combination of functional and histological examinations and exclusion of pathogen infection. Examination of transbronchial biopsy is of significance for the diagnosis. LONIPC may be considered as pathognomonic of cGVHD in the lung of patients after allo-HSCT; and cGVHD should be regarded as a useful diagnostic proof for LONIPC. Earlier treatment with corticosteroids and maintenance treatment may result in improved survival and decrease of the fibrotic residue.