Analysis of Panel Reactive Antibody in Patients Awaiting Renal Transplantation

Joo, Shin Young; Ha, Jongwon; Kim, Sang Joon; Park, Myoung Hee

Abstract

BACKGROUND: We performed panel reactive antibody (PRA) tests in renal transplantation candidates registered to the Korean Network for Organ Sharing (KONOS) and analyzed the results of PRA tests in relation to the results of HLA crossmatch (XM) tests and transplantation history.
METHODS
From 833 patients awaiting cadaveric renal transplantation in the KONOS registry, 122 (98 patients) XM (NIH or AHG)-positive and 147 (147 patients) XM-negative serum samples were selected for PRA test. Enzyme linked immunosorbent assay (ELISA)-PRA screening test was performed and HLA antibody specificities were identified by NIH and AHG PRA methods.
RESULTS
PRA positive rate was significantly higher in XM-positive group compared with XM-negative group (ELISA-PRA, 70.5% vs. 21.8%; AHG-PRA [PRA > or =10%], 73.9% vs. 9.6%). Donor specific antibodies were defined in 52.5% (64/122), whereas false positive XM results were suspected in 20.5% (25/122) of the XM-positive samples. Patients with transplantation histories showed significantly higher positive rates for ELISA-PRA (78.7% vs. 30.8%) and AHG-XM tests (78.2% vs. 29.3%). Highly sensitized patients (AHG-PRA > or =80%) showed significantly higher cumulative waiting rate (88.9% vs. 60.2% at 4 years) and longer waiting time (3.8 vs. 3.6 years) (Kaplan Meier method, P=0.037). PRA positive rate in the total renal transplantation candidates in the KONOS registry was estimated to be 33.9% for ELISA-PRA and 21.7% for AHG-PRA (PRA > or =10%), and the proportion of highly sensitized (PRA > or =80%) patients was estimated to be 5.4%.
CONCLUSIONS
Pre-transplantation PRA as a routine test is needed in cadaveric renal transplantation for effective and fair allocation of organs in Korea.