Related Experiment Video
Updated: May 8, 2026
Analysis of HBV-Specific CD4 T-cell Responses and Identification of HLA-DR-Restricted CD4 T-Cell Epitopes Based on a Peptide Matrix
Published on: October 20, 2021
HLA-DQ barrier: effects on cPRA calculations
Anat R Tambur1, Joseph R Leventhal, R Carlin Walsh
11 Transplant Immunology Laboratory, Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL. 2 Department of Surgery, Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL. 3 Department of Internal Medicine, Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL. 4 Address correspondence to: Anat R. Tambur, D.M.D., Ph.D., D[ABHI], Transplant Immunology Laboratory, Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL.
Background:
Panel-reactive antibody (PRA) testing provides assessment of the breadth of sensitization a patient might have against human leukocyte antigen (HLA) antigens. The evolution of calculated PRA (cPRA) reflects the commitment of the transplant community to increase accessibility and promote equity to all patients awaiting kidney transplantation. Recent data from our center and others, however, suggested that a significant diversity of HLA-DQ antigens is not captured, which may lead to inequity in allocating cPRA points.
Methods:
HLA-DRB1-DQA1-DQB1 typing of 2182 individuals was evaluated for this study using Luminex-based sequence-specific oligonucleotide typing. A total of 3182 haplotypes were confirmed to have the level of resolution required for this study.
Results:
The diversity of HLA-DQαβ alleles is greater than what is apparent using the serologic equivalents. The distribution of these alleles within a serologic group varies, with some alleles being more frequent than others; therefore, their representation within the current cPRA system is inaccurate. Three informative examples are given. Haplotypes of DR antigens with DQαβ alleles did not always follow the common published linkage disequilibrium, especially in populations where there is greater genetic diversity.
Conclusions:
The current cPRA system does not take into account the distribution of molecular equivalents within DQ serologic specificities. This can result is inequitable allocation of sensitization points and disadvantaging the more sensitized patients. To ameliorate this situation, the United Network for Organ Sharing system should allow inputting HLA-DQαβ alleles both for donor typing and as antibody specificities, which will lead to better representation of unacceptable DQ alleles and improve organ allocation equity.
More Related Videos
08:07Personalized Peptide Arrays for Detection of HLA Alloantibodies in Organ Transplantation
Published on: September 6, 2017
07:26High-resolution Melting PCR for Complement Receptor 1 Length Polymorphism Genotyping: An Innovative Tool for Alzheimer's Disease Gene Susceptibility Assessment
Published on: July 18, 2017
