This study is for children age 0-2 who have been diagnosed with severe combined immunodeficiency (SCID). In this study, participants will be randomized (select by chance) into groups that will decide the dose of chemotherapy they will receive, receive chemotherapy prior to a blood stem cell transplant, and have blood drawn for research tests. The purpose of this research study is to find out if lower doses of a chemotherapy drug called busulfan before stem cell transplant can help patients with SCID, and to see if the device the CliniMACS® is effective in preparing donor stem cells before the transplant. Participants can expect to be in this study for up to 3 years.

This study is for subjects that are about to receive high dose cyclophosphamide before a blood or bone marrow transplant (BMT). The investigational drug in this study is Olanzapine. This research is being done to find out whether adding olanzapine to standard medications will be helpful in controlling chemotherapy induced nausea in children. The total length of participation in this study will depend on how many days you are scheduled to receive chemotherapy, but can be up to a maximum of 2 weeks. We will review your chart for 100 days after transplant. There will be no extra visits to MUSC due to participating in the research study.

This study is for patients that have been diagnosed with Epstein-Barr Virus associated Post-Transplant Lymphoproliferative Disorder (EBV-PTLD). The investigational drug in this study is tabelecleucel. Tabelecleucel is a product containing special immune allogeneic cells, called EBV-Cytotoxic T Lymphocytes (EBV-CTLs), that are made in the laboratory starting with cells from a healthy person who is immune to EBV. The purpose of this study is to test how well tabelecleucel works to treat EBV-PTLD following SOT in patients who have not responded to rituximab or rituximab plus chemotherapy treatment and to see what side effects happen. Your participation will help us to understand more about tabelecleucel. In the first 12-month period, participants will be asked to come to the clinic for an estimated 11 to 19 study visits and a minimum of 2 scans, depending on the number of cycles of treatment they are given. After treatment is done, participants will enter into the follow-up phase, and will continue to come into the clinic for scheduled check-ups for up to 24 months after the first dose of tabelecleucel was given. Participant information on the status of their disease and any new treatment will be collected for up to an additional 3 years. Participants can expect to be in this study for up to five years total.

This study is for patients that have had a Hematopoietic Stem Cell Transplant (HSCT) and still have persistent Cytomegalovirus (CMV), adenovirus and/or Epstein-Barr Virus (EBV) infection; or have a Primary Immunodeficiency Disorder (PID) with one or more viral infections that persist. The primary purpose of the study is to evaluate whether most closely HLA-matched multivirus-specific T cell lines obtained from a bank of allogeneic virus-specific T cell lines (VSTs) have antiviral activity against three viruses: EBV, CMV and adenovirus. Participants can expect to be on this study for about 12 months.

This study is for patient that have been diagnosed with suspected lower respiratory tract infection. The purpose of this study is to evaluate a new test that may be able to find more lung infections than current tests can. This new test is called next-generation sequencing and looks in respiratory secretions for bacteria, viruses, fungi, and other organisms that may cause infection. We hope to learn more about the usefulness of this new test in identifying infections.