Significance of the intraindividual variability of HLA IgG antibodies in renal disease patients observed with different beadsets monitored with two different secondary antibodies on a Luminex platform

AbstractThe accurate measurement of anti-HLA alloantibodies in transplant candidates is required for determining the degree of sensitization and for the listing of unacceptable antigens for organ allocation. Both the configuration of the HLA molecules coated on the beads and the nature of detection antibodies may impede assessment of the presence and strength of anti-HLA IgG- with the Luminex single-antigen-bead assay. Sera antibodies of the end-stage renal disease patients were compared using LIFECODES (LC) and LABScreen (LS) beadsets monitored with polyclonal-Fab (IgHPolyFab) and monoclonal-IgG (FcMonoIgG) second antibodies. Positive results at mean fluorescence intensity (MFI)  >  500 (at serum dilution 1/10) were used to calculate panel reactive antibody (cPRA) levels. LS-beadsets are coated with monomeric variants in addition to intact HLA antigens with or without peptides, while LC-beadsets are devoid of monomeric variants and with lesser levels of peptide-free heterodi mers. Consequently, IgG antibodies against both classes of HLA were reactive to more antigens with LS than with LC-beadsets. For both classes, MFIs were also frequently higher with LS than with LC. For HLA-I, MFIs were higher withIgHPolyFab than withFcMonoIgG with the exception of sera with MFIs>  5000 where they were comparable. For HLA-II, the reverse occurred, with significantly higher levels withFcMonoIgG regardless of the beadsets. The intraindividual variability observed between beadset...
Source: Immunologic Research - Category: Allergy & Immunology Source Type: research