Management of noninfectious lung injury following hematopoietic cell transplantation

Over the past 20 years, tremendous strides have been made to decrease treatment-related morbidity and mortality following allogeneic transplant, including management of acute and chronic lung injury. Within this context, three distinct entities are recognized, idiopathic pneumonia syndrome (IPS), bronchiolitis obliterans syndrome (BOS), and bronchiolitis obliterans organizing pneumonia (BOOP). Management options for each of these disorders are now reviewed.

A recent pilot study and subsequent phase II trial suggest that tumor necrosis factor (TNF) inhibitors hold promise in treating IPS. A randomized phase III trial ended prematurely, without a definitive conclusion regarding TNF inhibitors established. Few prospective trials for BOS have been performed, with current therapy based on observational studies and small case reports. Therapy for BOOP is based upon minimal clinical evidence.

Although corticosteroids remain the backbone of therapy for IPS, BOS, and BOOP, TNF inhibition may augment management of IPS and potentially BOS as well. Diagnostic criteria for IPS and BOS have been established, although optimal treatment strategies will ultimately require consensus monitoring and response criteria, coupled with an improved understanding of the pathophysiology underlying each disorder. For BOS and BOOP in particular, therapy has been based upon a paucity of data and anecdotal experiences.