Regional HLA differences in Poland and their effect on stem cell donor registry planning

Area of Science:

• Immunogenetics
• Hematology
• Population Genetics

Background:

• Regional variations in Human Leukocyte Antigen (HLA) frequencies can influence hematopoietic stem cell donor selection.
• Optimizing donor recruitment strategies requires understanding population-specific HLA allele distributions.

Purpose of the Study:

• To investigate regional differences in HLA allele frequencies among Polish stem cell donors.
• To assess the potential impact of region-specific donor recruitment on matching probabilities for Polish patients.

Main Methods:

• Analysis of a large dataset (n=123,749) of registered Polish stem cell donors.
• Regional stratification based on 1-digit postal codes.
• Simulations using region-specific HLA haplotype frequencies to predict matching probabilities.

Main Results:

• Significant variation in donor numbers across different postal code regions.
• Simulations indicated that recruitment in southeastern regions (0, 2, 3, 4) could increase matching probabilities for Polish patients.
• Conversely, recruitment in northern regions (1, 7, 8, 9) showed an opposite trend.
• Overall, observed HLA frequency differences between regions were minor.
• Haplotype frequency estimations exhibited sample size effects even within the range of 5,000 to 20,000 donors.

Conclusions:

• The study does not provide strong evidence to support regionally focused stem cell donor recruitment efforts in Poland due to small HLA frequency variations.
• The observed sample size effects on haplotype frequency estimations warrant further investigation, especially considering the typically smaller sample sizes in published studies.