The investigators are collecting blood samples to learn more about how the body's immune
system recovers after stem cell transplant (SCT). Participants are either previous recipients
of a stem cell transplant, or a donor of stem cells for transplant.
The investigators propose to systematically collect specimens of blood and plasma from donors
and recipients of SCT. For recipients, samples may be collected at the following time points
or transplant milestones. If the recipient is not able to be present at SCCC/UMHC during the
window of one of these milestone visits, the specified collection may be missed due to
unavailability. The recipient may then resume sample collection at the subsequent collection
period. Collections may be received within 30 days prior to transplantation, at approximately
30 days (+/- 7 business days), 60 days (+/- 14 business days), 100 days (+/- 21 business
days), six months (+/- 21 business days), one year(+/- 21 business days), and annually(+/- 21
business days) thereafter following SCT. Up to three additional samples, collected no more
frequently than weekly, may be collected if recipients experience complications (e.g., viral
reactivation) associated with abnormal T cell immune recovery after SCT. A sample may also be
removed that is equal to or less than 1% of the total product volume of the donor collection,
prior to recipient infusion. For donors, one sample will be collected prior to stem cell
mobilization with G-CSF.
Assays to be performed may include the following: 1) Functional studies of antigen-specific T
cell responses to pathogens (e.g., cytomegalovirus) and to other antigens (e.g., to defined
epitopes that have been identified as potential malignancy-specific targets)(8,15); 2) T cell
immunophenotyping (to define the recovery of T cell subsets associated with a "naive" or
"memory" T cell phenotype)(16,17); 3) Studies examining the molecular diversity of the T cell
repertoire(18,19); 4) Studies to identify recent thymic emigrants in the peripheral blood to
determine the extent of thymic function occurring at steady state or following BMT(11,20);
and 5) Assays of plasma levels of cytokines (e.g., interleukin-7) that may be important in T
cell reconstitution(21,22). Some or all of these studies may be performed at the time of
collection. In most cases, cryopreserved PBMC or plasma samples will be used for these
assays. Cryopreserved cells in excess of requirements for studies of immune reconstitution
will be banked to allow access by other investigators to these specimens.
By increasing our understanding of immune recovery post-stem cell transplantation, the
investigators will be able to develop strategies to improve immune recovery and reduce
graft-versus-host disease to be tested in future clinical trials. It is the investigators'
goal to develop graft engineering strategies to improve both of those important clinical
problems in SCT patients.
The purpose of this protocol is to study immune reconstitution and graft-versus- host disease
in stem cell transplant recipients, and to study the role of donor cells and the clinical
regimen on those processes.
- Stem Cell Transplant Donor
- Stem Cell Transplant Recipient