HLA Matching - Unrelated Umbilical Cord Blood Transplantation

The aim of this protocol is to clarify the role of HLA matching in unrelated umbilical cord
blood (UCB) transplantation and to identify the level of HLA matching required assuring
successful outcome of unrelated UCB transplantation.

The study will answer the following questions:

1. Is HLA matching beneficial to unrelated UCB transplantation?

2. Which HLA loci, HLA-A, B, C, DRB1, or BQB1 is/are important to math, or alternatively to
mismatch, to improve graft survival?

3. Which HLA loci, HLA-A, B, C, DRB1, or BQB1 mismatches is/are "permissive mismatches" or
well tolerated mismatches?

4. What level of typing resolution (low, intermediate, or hgh) is required to perform
patient/donor H:A matching?

By studying the cells and blood of donors and recipients, we may learn more about improving
the tissue matching between unrelated donors and their recipients. Also, we hope to learn if
an additional level of matching testing improves the results of the transplant treatment.
Increasing knowledge about tissue matching could result in the improved long-term survival of
cord blood transplant recipients.

Inclusion Criteria:

- Pediatric Patients undergoing an unrelated umbilical cord blood transplantation.

Exclusion Criteria:

- Refusal to participate in study.