Evaluation of Flow Cytometric Crossmatch Results in Comparison with Donor-specific Antibodies Detected by Luminex-PRA Tests in Organ Transplantation Patients / 대한이식학회지

ABSTRACT

BACKGROUND: Two of the most sensitive methods for detecting donor-specific HLA antibodies (DSAs) are solid phase panel reactive antibody (PRA) assay using Luminex platform (Luminex-PRA), and a cell-based flow cytometric crossmatch (FCXM) test. We evaluated FCXM results in relation to DSAs detected by the Luminex-PRA method in solid organ transplantation candidates or post-transplant follow-up patients. METHODS: A total of 171 donor-recipient pairs were evaluated by Luminex-PRA (LIFECODES Class I and Class II ID kits; Gen-Probe, USA) and FCXM (T- and B-cells) tests. DSA levels were analyzed using a sum of median fluorescence intensity (MFI) values, and FCXM results were analyzed using MFI ratios. RESULTS: Class I and II DSAs were detected in 11.7% (20/171) and 11.1% (19/171) of tested sera, respectively. T-FCXM was negative in 97.4% (147/151) of Class I DSA negative sera, and B-FCXM was negative in 99.3% (137/138) of Class I and II DSA negative sera. T-FCXM was positive in 91.7% (11/12) of sera with moderate to strong Class I DSAs and B-FCXM was positive in 88.9% (16/18) of sera with moderate to strong Class II and/or Class I DSAs in the evaluation of sensitivities of FCXM in relation to DSA. There were significant correlations between FCXM ratios and DSA levels for both T-FCXM (P=0.008) and B-FCXM (P97%) and the sensitivities of T- and B-FCXM were satisfactory (>88%) in detecting moderate to strong DSAs.