Etanercept therapy for late-onset idiopathic pneumonia syndrome after nonmyeloablative allogeneic hematopoietic stem cell transplantation

Idiopathic pneumonia syndrome (IPS) is a noninfectious pulmonary complication of allogeneic hematopoietic stem cell transplantation (AHSCT), which usually develops within the first 100 days after transplantation. Donor T-cell-derived tumor necrosis factor-α (TNF-α) may play a crucial role in the pathogenesis of IPS, and inhibition of TNF-α has been used as a therapeutic option. We report two patients who had late-onset IPS about day 150 after nonmyeloablative AHSCT (NMA-AHSCT). They responded well to etanercept in combination with standard immunosuppressive drugs. Both patients had relapses and responded to retreatment with etanercept-based therapy. One patient was alive at 30 months after the initial diagnosis on long-term maintenance therapy with etanercept. The second patient was lost to follow-up at our institution but died 13 months after the onset of IPS. Our two cases showed that IPS could develop late after NMA-AHSCT and inhibition of TNF-α activity can be therapeutically effective.