Luminex donor‐specific crossmatches

Abstract

In Luminex bead-based screening assays, color-coded microspheres coated with human leukocyte antigens (HLA) are used to identify both complement-binding and non-complement-binding HLA class I and II antibodies in recipient sera. Many laboratories rely on their specificity detection and use the information obtained for allocation of donor organs. A donor-specific crossmatch in the Luminex technique (LumXm) is for that reason desirable. A LumXm, in which the actual donor HLA are coated onto specific capture beads, was tested for 88 pre- and posttransplant sera of 18 recipients. The results were compared with previously published flow cytometric crossmatch (FCXm) results for the same donor-recipient combinations. All sera were also examined by Luminex single antigen (SA) tests. Class I LumXm detected 24 of 27 T-cell positive FCXm (89%) and class II 15 of 22 B-cell positive FCXm (68%). Sensitivity of LumXm for class I and II was 89% and 68% and specificity was 98% and 97%, respectively. Discrepant LumXm results were obtained in 13 sera of nine patients (15%). In general, based on SA testing, FCXm showed false-positive results for class I and LumXm gave false-negative and positive results for class II. The LumXm test was proven not to react with recipient sera containing DQ antibodies only, also DP detection was insufficient. The validity of the LumXm has been shown for class I, but its value for class II is uncertain. HLA-DR is most probably correctly identified, the validity for DQ and DP is doubtful.

Low levels of human leukocyte antigen donor-specific antibodies detected by solid phase assay before transplantation are frequently clinically irrelevant

“…This high sensitivity of SPA may be related in part to the cut-off level fixed at 500 MFI according to the manufacturer's criteria. Indeed recent studies have reported a higher cut-off value [12][13][14].…”

Clinical significance of anti-HLA antibodies detected by Luminex®: Enhancing the interpretation of CDC-BXM and important post-transplantation monitoring tools

“…Several studies have shown a good correlation between lysate crossmatch and Luminex antibody screening PRA and SAB tests in detecting HLA-A, B and DR DSA [43,44]. However the use of lysate crossmatch is currently restricted by its low sensitivity to detect DQ and DP DSA [43,44].…”

“…However the use of lysate crossmatch is currently restricted by its low sensitivity to detect DQ and DP DSA [43,44]. Lysate crossmatch has several advantages compared with CDC crossmatch, in that (1) lysate can be stored long term and thus it is especially useful for post-transplantion monitoring; (2) it detects only anti-HLA IgG DSA, so it prevents false-positive results caused by irrelevant antibodies; and (3) it may detect rare HLA antigens because the sensitivity does not rely on bead panel but is specific to the organ donor antigens.…”

Luminex and antibody detection in kidney transplantation

“…After addition of a IgG-phycoerythrin conjugated secondary antibody, fluorescence is read using the Luminex instrument. Billen et al [46] reported, for the first time, a study on donor-specific Luminex crossmatch. Results obtained were compared with those of flow cytometry crossmatch, performed on the same donor-recipient pairs.…”