An intermediate-sized donor registry experience: HLA barriers in matching procedures

Area of Science:

• Immunogenetics
• Transplantation Science
• Hematology

Background:

• Hematopoietic stem cell transplantation (HSCT) success relies on timely identification of matched unrelated donors (MUDs).
• Understanding HLA allele and haplotype frequencies is critical for predicting MUD availability in specific patient populations.

Purpose of the Study:

• To analyze the probability of finding a 9-10/10 MUD for Croatian patients undergoing unrelated HSCT.
• To investigate the distribution of HLA alleles and haplotypes in relation to MUD matching status.

Main Methods:

• Retrospective analysis of 738 unrelated Croatian HSCT patients.
• Evaluation of gender matching, donor origin, HLA allele and haplotype frequencies.
• Statistical comparison of HLA profiles between patients with 10/10 MUD and 9/10 MUD.

Main Results:

• Nearly 70% of patients had a 10/10 MUD; 55% of 9/10 MUD cases involved a 1st field resolution mismatch.
• Significant differences in HLA allele frequencies were observed, with specific alleles (B*08:01, C*07:01, DRB1*03:01) more common in 10/10 MUD patients.
• Distinct HLA haplotype distributions were found, including a five-locus haplotype significantly associated with 10/10 MUD matches.

Conclusions:

• The study provides valuable data for estimating MUD probability for Croatian HSCT patients.
• Identified HLA allele and haplotype patterns can refine donor search strategies.
• This research contributes to improving HSCT outcomes by facilitating MUD selection.