Background: Various late-onset noninfectious pulmonary complications may occur after allogeneic hematopoietic stem cell transplantation (HSCT). Interstitial lung diseases (ILD) are often overlooked, and few data are available.

Methods: We retrospectively analyzed the clinical features, pulmonary function tests, radiological features and outcomes of allogeneic HSCT recipients who were diagnosed with a noninfectious ILD and were managed in our center between 2001 and 2010.

Results: Forty patients were analyzed. The median time from transplant to ILD was 11.3 months. The donor hematopoietic stem cell source was peripheral blood stem cells in 75% of the cases. Seventy percent of the patients had extra-thoracic chronic graft versus host disease at ILD diagnosis. We identified two lung computed tomography (CT) scan patterns according to the predominance of ground glass opacities or alveolar consolidations. Restrictive ventilatory defect was the main pulmonary function pattern. Lung histology was available for seven patients and showed diffuse alveolar damage, non-specific interstitial pneumonia, organizing pneumonia or lymphoid interstitial pneumonia. Thirty-five patients (87.5%) were treated with systemic steroids. Thirteen patients died (32.5%), 10 of respiratory failure. The median survival rate at 24 months was 61%.

Conclusion: This study highlights the existence of noninfectious post-allogeneic HSCT ILD and provides new insights into the characteristics of these illnesses.