Stem cell transplantation and lung dysfunction.

PURPOSE OF REVIEW: To identify factors that impact the incidence and severity of lung dysfunction after haematopoietic stem cell transplantation (HSCT) for preventive and therapeutic purposes.

RECENT FINDINGS: Respiratory failure from lung dysfunction after HSCT is a serious and often fatal transplant-related complication, but recent data reveal decreasing incidence and improving outcome over time. Idiopathic pneumonia syndrome (IPS) and bronchiolitis obliterans are now recognized as part of a spectrum of post-HSCT lung diseases involving both aspects of innate and adaptive immune responses, but may differ in the main lung structure affected: alveolar versus airway epithelium. There exists a strong association between acute graft-versus-host disease (GVHD) and IPS, and bronchiolitis obliterans is pathognomonic of chronic GVHD. Experimental models of IPS and bronchiolitis obliterans have proven useful to test strategies designed to limit lung injury including the effects of allogeneity, chemoradiotherapy and stem cell therapy. Recent advances in critical care practices, early diagnosis and utilizing ARDS Network ventilatory and conservative fluid management recommendations have also contributed to better outcome from lung dysfunction after HSCT.

SUMMARY: Understanding the factors that contribute to post-HSCT lung injury should lead to safer transplant practices that will allow the broader use of HSCT for sicker children with comorbidities.