Etanercept in Treating Young Patients With Idiopathic Pneumonia Syndrome After Undergoing a Donor Stem Cell Transplant

Inclusion Criteria: * Diagnosis of acute, noninfectious idiopathic pulmonary dysfunction (IPS) as defined by the following: * Evidence of diffuse lung injury occurring within the first several months after hematopoietic stem cell transplantation for which an infectious etiology is not identified. To meet the criteria for IPS there must be: * Evidence of widespread alveolar injury * Diffuse multi-lobar infiltrates on chest x-ray or CT scan * Evidence for abnormal respiratory physiology based upon 1 of the following: * Room air oxygen saturation \< 93% * Supplemental oxygen required to maintain an oxygen saturation ≥ 93% * Absence of active lower respiratory tract infection, defined as Bronchoalveolar lavage (BAL)-negative for infection based on one of the following: * Gram stain, fungal stain, acid-fast bacilli stain * Bacterial culture (a quantitative culture ≥ 10\^4 colony-forming units/mL is considered positive) * Fungal culture * Mycobacterial culture * Viral culture (respiratory syncytial virus \[RSV\], parainfluenza, adenovirus, influenza A and B, and cytomegalovirus \[CMV\]) * If direct fluorescent antibody (DFA) screening is performed on BAL, it must be negative for all viruses listed above * Pneumocystis carinii pneumonia by polymerase chain reaction (PCR), DFA stain, or cytology * Evidence of bilateral pulmonary infiltrates (on chest radiograph) * Patients may have diffuse al…