Immunologic Features of Respiratory Failure in Pediatric Hematopoietic Cell Transplantation (HCT) Recipients and Pediatric Oncology Patients

Study Summary

This study is being done because researchers want to learn more about genes that control the immune response in the participant's lungs and blood when the participant have lung disease leading to respiratory failure. Primary Objective To evaluate the feasibility of performing single cell gene expression analyses on tracheal aspirates from immunocompromised pediatric patients with immune compromising conditions, including HCT recipients. Secondary Objectives * To assess whether cell composition and activation states in longitudinally obtained tracheal aspirate and blood samples are able to distinguish unique immunopathology for each of the early post-HCT lung diseases. * To assess whether cell composition and activation states in longitudinally obtained tracheal aspirate and blood samples are different between two immunodeficient patient populations (alloHCT vs non alloHCT) with lung disease and respiratory failure. * To test the hypothesis that allogeneic T cell responses are implicated in the pathogenesis of early post-HCT lung diseases. Exploratory Objectives To correlate immune cell signaling in the lower respiratory tract and blood of patients with early post-HCT lung diseases with the presence or absence of pathogenic microbes at each site. To explore HLA testing in Tracheal Aspirates in samples where enough cells are present.