Effectiveness of Etanercept for Idiopathic Pneumonia Syndrome Following Stem Cell Transplantation (BMT CTN 0403)

Inclusion Criteria: Patients fulfilling the following criteria will be eligible for registration in this study: * Recipient of an allogeneic bone marrow, cord blood, or peripheral blood stem cell transplant. There are no restrictions based upon underlying disease, donor source, degree of human leukocyte antigen (HLA) match, intensity of the pre-transplant conditioning regimen, or the use of a prior donor leukocyte infusion * Evidence of acute lung injury, based upon the presence of bilateral pulmonary infiltrates (on chest radiograph) and a supplemental oxygen requirement * No more than 180 days post transplant Patients fulfilling the following criteria will be eligible for random assignment in this study: * BAL fluid negative for pathogenic microorganisms as assessed by gram stain and fungal stain * BAL fluid negative for pathogenic microorganisms, or test result pending, as assessed by the following tests: 1. Acid fast bacilli stain (AFB) 2. Bacterial culture (a quantitative culture of at least 10(4) CFU/mL is considered positive) 3. Viral cultures for respiratory pathogens, including Respiratory syncytial virus (RSV), adenovirus, parainfluenza, influenza A and B, and Cytomegalovirus (CMV) 4. Fungal and mycobacterial cultures 5. Pneumocystis carinii pneumonia (PCP) assay, by polymerase chain reaction (PCR), direct fluorescent antibody (DFA) stain, or cytology (per institutional guidelines) Exclusion Criteria: * Sepsis syndrome or hypotension in which inotropic support (excluding dopamine of no more than 5 mcg/kg/minute) is required * Bacteremia within 48 hours prior to study registration * Documented invasive fungal or systemic viral infection (excluding asymptomatic viruria) within 14 days prior to study registration * Evidence of CMV infection, based upon an abnormal PCR assay, antigenemia assay, or shell vial culture within 14 days of study registration * On mechanical ventilation for more than 48 hours at study registration * Evidence of congestive heart failure by clinical assessment * Participating in other investigational studies (Phase I, II, or III) for the treatment of acute GVHD within 7 days of study registration (patients enrolled in BMT CTN 0302 are ineligible for study entry) * Received etanercept within 14 days prior to study registration * Pregnant or breastfeeding * On more than 2 mg/kg/day of methylprednisolone equivalent for more than 48 hours, within 7 days prior to study registration * Known hypersensitivity to etanercept * History of active tuberculosis (TB) infection * History of chronic active hepatitis B or hepatitis C infection * Patients who have undergone a BAL within 72 hours of study registration are ineligible if the BAL fluid is known to be positive for pathogenic microorganisms * Patients who have relapsed or have developed progressive disease post-transplant