The DQ barrier: improving organ allocation equity using HLA-DQ information

Area of Science:

• Immunogenetics
• Transplantation immunology
• Molecular biology

Background:

• Current kidney allocation algorithms primarily use HLA-A, -B, and -DR loci.
• HLA-DQ unacceptable antigen assignment overlooks the polymorphic DQα chain, impacting antibody recognition.

Observation:

• Patients with HLA-DQ antibodies were analyzed for crossmatch (XM) outcomes.
• High-resolution HLA typing identified specific DQα/β allele combinations.

Findings:

• 24% of patients with HLA-DQ antibodies had negative flow XM due to allelic DQα/β mismatches.
• Virtual XM incorporating DQα/β combinations accurately predicted over 98% of XM results.

Implications:

• Excluding patients based on serologic HLA-DQ antigens may hinder transplant opportunities.
• Integrating DQα/β allele information can enhance virtual XM accuracy and promote equitable organ allocation.