Probability of success in the search for a related bone marrow donor in Cologne, Germany using HLA-A, -B and -DRB1 haplotype frequencies.

Daniel M Hellmann,Birgit S Gathof,Rolf Fimmers,Stela Radojska

doi:10.1111/tan.13356

Abstract

Between 2004 and 2013, 603 patients and their relatives (n = 1297) were typed as part of the search for a suitable HLA‐matched donor in their nuclear and extended families at the central service provider for transfusion medicine at the University Hospital of Cologne. The high success rate in finding donors over the years at our center (38.1%) led us to examine our database retrospectively in order to evaluate the donor search and haplotype frequencies (HFs) in the sample. Our goal was to identify the factors contributing to this high success rate and also to compare the HFs we observed with other reported haplotype frequency estimations (HFE) for the Cologne area. Probability estimations for a successful donor search were constructed based on the HFEs for the sample.

Highlights

Within the scope of allogeneic hematopoietic stem cell transplantation (HSCT), the search for suitable donors within the families of patients has many advantages over an unrelated donor search
To derive the corresponding haplotype frequencies (HFs), an expectation-maximization (EM) algorithm (FAMHAP) was used, which iteratively calculates the maximum likelihood (ML) of the phenotypic HLA data and reconstructs where possible the four haplotypes of a nuclear family based on the data with an assumed Hardy-Weinberg equilibrium (HWE).[19,20]
In order to check the compatibility in our institute, we provided an initially low resolution typing at the HLA-A, -B and -DRB1 loci in accordance with European Federation for Immunogenetics (EFI) standards.[21]

Summary

Introduction

Within the scope of allogeneic hematopoietic stem cell transplantation (HSCT), the search for suitable donors within the families of patients has many advantages over an unrelated donor search. We observed that in most instances, family donors are highly motivated to help their relatives, and the timespan between the occurrence of the disease and the HLA typing is in general much lower than in the search for an unrelated donor. Our goal was to precisely estimate actual success rates in the search for donors within nuclear and extended families as well as to estimate the haplotype frequencies (HFs) for the sample in Cologne. This effort seemed worthwhile in light of the fact that reliable data about the distribution of HFs in the population are important for donor databases in order to ensure that the recruiting of unrelated stem cell donors can be sensibly planned.[9]. Our overarching aim was to identify the causes of these high success rates in wileyonlinelibrary.com/journal/tan

Objectives

Methods

Results

Conclusion