Vancomycin-Polymyxin B in Preventing Graft-Versus-Host Disease in Children Undergoing Donor Stem Cell Transplant

Inclusion Criteria

• Recipient of 9/10 or 10/10 (human leukocyte antigen [HLA]-A, -B, -C, -DRB1, -DQB1) matched bone marrow allogeneic hematopoietic stem cell transplantation (HSCT) OR 4/6, 5/6, and 6/6 (HLA-A, -B, -DR) matched cord blood allogeneic HSCT
• Participants may have underlying malignant or non-malignant hematologic disease, except for primary immunodeficiency, as the indication for their allogeneic HSCT; patients with immune dysregulation syndromes such as familial or secondary hemophagocytic lymphohistiocytosis (HLH) are eligible
• Participants may receive either a myeloablative or a non-myeloablative (reduced-intensity) conditioning regimen
• Graft-versus-host disease (GVHD) prophylaxis with any of the following agents: calcineurin inhibitor, short-course methotrexate steroids, mycophenolate mofetil, and sirolimus
• Age >= 4 years old and toilet-trained; participants must be able to deposit stool samples directly into stool collection containers
• Lansky/Karnofsky performance status >= 60%
• Ability to understand and/or the willingness of their parent or legally authorized representative to sign a written informed consent document
• HEALTHY BONE MARROW DONORS: Healthy individuals, ages >= 4 years and toilet-trained, who have been identified by Boston Children's Hospital (BCH) or Dana Farber Cancer Institute (DFCI) providers as 9/10 or 10/10 (HLA-A, -B, -C, -DRB1, -DQB1) matched, bone marrow donors for transplantation will also be eligible to participate in this study; healthy donors may be related or unrelated to the bone marrow recipient

Exclusion Criteria

• Patients undergoing allogeneic HSCT for correction of a primary immunodeficiency disorder (e.g. severe combined immunodeficiency [SCID])
• Patients with age =< 10 years undergoing HSCT with a matched sibling donor; these patients are at very low risk of acute GVHD and do not receive gut decontamination per our institutional standard practice
• Participants receiving GVHD prophylaxis with drugs other than calcineurin inhibitor, short-course methotrexate, steroids, mycophenolate mofetil, or sirolimus
• History of allergic reactions attributed to oral vancomycin or oral polymyxin B
• Participants undergoing active therapy for immune-mediated or infectious colitis upon admission for allogeneic HSCT
• Participants receiving antibiotic therapy for treatment of a bacterial infection or bacterial prophylaxis upon admission for allogeneic HSCT; use of any agent (e.g. sulfamethoxazole/trimethoprim) for prophylaxis of pneumocystis jirovecii pneumonia is permitted; concurrent use of anti-fungal and anti-viral therapies is also permitted
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection or psychiatric illness/social situations that would limit compliance with study requirements