Background: Transplantation of hematopoietic stem cells (HSC) is an effective treatment for a number of patients with life-threatening hematologic diseases. HSC donors can be found in the family of the patient or in registries of unrelated donors. In the present study, the search procedure within the last two years for an allogeneic HSC donor at the University of Düsseldorf is analyzed.
Patients and methods: During 1997 and 1998, an early search for a related HSC donor in the family was performed for 70 high risk pediatric patients. During the same period, the search for an unrelated HSC donor for 116 adult and pediatric patients was performed. Low resolution HLA-A and -B typing was performed by serology in combination with DNA-typing. High resolution typing of HLA-A, -B and -C was carried out by DNA-sequencing. Low resolution HLA-DRB- und HLA-DQB1-typing was done solely by DNA-typing and high resolution typing of these genes was performed by DNA-sequencing.
Main results: For 51 of 70 high risk pediatric patients (73%), no family donor could be defined, 16 of 70 patients (23%) had a genotypically identical sibling and for three of 70 patients (4%) an HLA-acceptable donor in the extended family could be identified. The search for an unrelated HSC donor was successful in 74% of the adult and pediatric patients lacking such a family donor. Most noteworthy, nearly all of the HLA-acceptable donors were identified from that group of donors in the registries, which were not only HLA-A and HLA-B, but also HLA-DR pretyped.
Conclusion: These data show, that a growing number of pediatric patients with high risk leukemia need an unrelated HSC donor and that HLA-ABDR-pretyped registries present the optimal prerequisite to identify an HSC donor for most of the patients. In addition, 25% of the patients with no family or unrelated HSC donor require HSC transplants from alternative donors like unrelated Cord Blood (CB) from high quality cord blood banks.