Ann Lab Med.  2012 Jan;32(1):66-72. 10.3343/alm.2012.32.1.66.

Application of Calculated Panel Reactive Antibody Using HLA Frequencies in Koreans

• Jang JY
• Kim YJ
• Kim Y
• Park YJ
• Han K
• Oh EJ

• KMID: 1781440
• DOI: http://doi.org/10.3343/alm.2012.32.1.66

Abstract

BACKGROUND
Introduction of the Luminex panel reactive antibody (PRA)-single antigen (SA) assay has increased the detection rates of unacceptable antigens in sensitized patients; the calculated PRA (CPRA) level represents the percentage of actual organ donors that express 1 or more of these unacceptable antigens. We developed a CPRA calculator based on the HLA frequencies in Koreans to measure sensitization levels in Korean patients.
METHODS
To develop the calculator, we obtained the HLA-A, HLA-B, and HLA-DR phenotypes of 1,622 Koreans, and compared these with previously reported frequencies in Koreans. Sera from patients awaiting kidney transplantation were tested for HLA antibodies by Luminex PRA-screen, PRA-identification (ID), and PRA-SA assays. The measured %PRA from the PRA-screen (N=55) and PRA-ID (N=71) were compared to the %CPRA for the unacceptable antigens obtained from PRA-SA.
RESULTS
Phenotype frequencies used for the CPRA calculator agreed with previously reported data. The concordance rates among the 3 PRA methods for the detection of class I and class II antibodies were 76.1-81.8% (kappa, 0.519-0.636) and 72.7-83.6% (0.463-0.650), respectively. For the detection of broadly sensitized sera (>50% or >80%), the concordance rates were over 80%. In sera with 80-100% CPRA, 91.7% and 94.4% of the samples had concordant results (80-100% PRA) in the PRA-screen and PRA-ID assay, respectively.
CONCLUSIONS
Although further clinical studies are required to confirm the benefits of CPRA values, adoption of CPRA analysis based on HLA frequencies in Koreans may be useful for sensitization measurements and organ-allocation algorithms.

Keyword

Panel reactive antibody (PRA); Calculated panel reactive antibody (CPRA); Transplantation; HLA antibody; Sensitization; Unacceptable antigen

MeSH Terms

*Algorithms
HLA Antigens/immunology
HLA-B Antigens/immunology
HLA-DR Antigens/immunology
*Histocompatibility Testing
Humans
Isoantibodies/*blood/immunology
Phenotype
Republic of Korea

Figure

• 

  Fig. 1 CPRA calculator based on the HLA-A, HLA-B, and HLA-DR phenotypes of 1,622 Korean donors.

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  Fig. 2 Distribution of PRA values (A, by PRA-screen; B, by PRA-ID) for each CPRA group.*The concordance rate between the PRA and CPRA values for each CPRA group is noted on the bar.

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