Luminex donor-specific crossmatches

Area of Science:

• * Immunology
• * Transplantation immunology
• * Clinical diagnostics

Background:

• * Luminex bead-based assays are crucial for identifying human leukocyte antigen (HLA) antibodies in recipient sera for donor organ allocation.
• * A donor-specific Luminex crossmatch (LumXm) is desirable to enhance specificity in pre-transplant evaluations.
• * Existing flow cytometric crossmatch (FCXm) methods have limitations in specificity and can yield false positives.

Purpose of the Study:

• * To evaluate the clinical utility and accuracy of a donor-specific Luminex crossmatch (LumXm) for detecting HLA class I and II antibodies.
• * To compare LumXm performance against established flow cytometric crossmatch (FCXm) and Luminex single antigen (SA) testing.
• * To determine the reliability of LumXm for specific HLA loci, including DR, DQ, and DP.

Main Methods:

• * Luminex crossmatch (LumXm) assays were performed using donor HLA-coated beads on 88 pre- and post-transplant sera from 18 recipients.
• * Results were compared with existing flow cytometric crossmatch (FCXm) data and Luminex single antigen (SA) testing.
• * Sensitivity and specificity of LumXm were calculated for both HLA class I and class II antibodies.

Main Results:

• * LumXm demonstrated high sensitivity (89%) and specificity (98%) for detecting HLA class I antibodies, correlating well with T-cell positive FCXm.
• * For HLA class II antibodies, LumXm showed lower sensitivity (68%) and specificity (97%), with discrepancies noted in 15% of cases.
• * LumXm exhibited insufficient reactivity for HLA-DQ and HLA-DP antibodies, suggesting potential false negatives and positives for these specificities.

Conclusions:

• * Luminex crossmatch (LumXm) is a valid and accurate method for detecting donor-specific HLA class I antibodies, aiding organ allocation.
• * The reliability of LumXm for HLA class II antibody detection, particularly for DQ and DP, remains uncertain and requires further investigation.
• * While LumXm shows promise, its application for class II crossmatching may need refinement to ensure accurate donor-recipient compatibility assessment.