Article

Original Article

Ann Lab Med 2012; 32(1): 66-72

Published online January 1, 2012 https://doi.org/10.3343/alm.2012.32.1.66

Copyright © Korean Society for Laboratory Medicine.

Application of Calculated Panel Reactive Antibody Using HLA Frequencies in Koreans

Ji-Young Jang, M.D., Yoon-Joo Kim, M.D., Yonggoo Kim, M.D., Yeon-Joon Park, M.D., Kyungja Han, M.D.,
and Eun-Jee Oh, M.D.

Department of Laboratory Medicine, School of Medicine, The Catholic University of Korea, Seoul, Korea

Correspondence to: Eun-Jee Oh
Department of Laboratory Medicine, Seoul St. Mary’s Hospital, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701, Korea
Tel: +82-2-2258-1641
Fax: +82-2-2258-1719
E-mail: ejoh@catholic.ac.kr

Received: September 5, 2011; Revised: September 23, 2011; Accepted: October 24, 2011

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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.

Keywords: Panel reactive antibody (PRA), Calculated panel reactive antibody (CPRA), Transplantation, HLA antibody, Sensitization, Unacceptable antigen