Bead-by-bead normalization of single antigen assays: A necessary step for accurate detection of weak anti-HLA antibodies.

Autor: Usureau C; Laboratoire d'Immunologie et Histocompatibilité, Hôpital Saint Louis, Paris, France.; INSERM UMR976, Institut de Recherche Saint-Louis, Université de Paris-Cité, Paris, France., Lhotte R; Laboratoire d'Immunologie et Histocompatibilité, Hôpital Saint Louis, Paris, France.; INSERM UMR976, Institut de Recherche Saint-Louis, Université de Paris-Cité, Paris, France.; MICS-Research Laboratory in Mathematics and Computer Science, Centrale Supélec, Paris-Saclay University, Gif-Sur-Yvette, France., Devriese M; Laboratoire d'Immunologie et Histocompatibilité, Hôpital Saint Louis, Paris, France.; INSERM UMR976, Institut de Recherche Saint-Louis, Université de Paris-Cité, Paris, France., Siemowski J; Laboratoire d'Immunologie et Histocompatibilité, Hôpital Saint Louis, Paris, France., Gabet L; MICS-Research Laboratory in Mathematics and Computer Science, Centrale Supélec, Paris-Saclay University, Gif-Sur-Yvette, France., Letort V; MICS-Research Laboratory in Mathematics and Computer Science, Centrale Supélec, Paris-Saclay University, Gif-Sur-Yvette, France., Taupin JL; Laboratoire d'Immunologie et Histocompatibilité, Hôpital Saint Louis, Paris, France.; INSERM UMR976, Institut de Recherche Saint-Louis, Université de Paris-Cité, Paris, France.
Jazyk: angličtina
Zdroj: European journal of immunology [Eur J Immunol] 2024 Nov; Vol. 54 (11), pp. e2451181. Date of Electronic Publication: 2024 Sep 05.
DOI: 10.1002/eji.202451181
Abstrakt: Ascertaining the presence of weakly positive anti-HLA donor-specific antibodies (DSA) in organ transplantation with multiplex single antigen beads assays may be challenging despite their high sensitivity due to technical variability issues. Through extensive datasets of Next-Generation Sequencing HLA typings and single antigen analyses, we reassessed the mean fluorescence intensity (MFI) positivity threshold of the assay to enhance accuracy. By showing that some beads were more prone to false positivity than others, we propose a nuanced approach that accounts for nonspecific intrinsic reactivities at the HLA antigen level, that is, on a bead-by-bead basis, as it enhances assay precision and reliability. This is substantiated by a comprehensive statistical analysis of MFI values and the implementation of the determination of a "Quantile Adjusted Threshold 500" (QAT500) value for each bead. Applied to DSA detection during patients' follow-up, this approach discriminated better and earlier low-strength DSA that would later raise their MFI above the clinically relevant threshold of 3000. Moving from a subjective interpretation to a more objective and precise methodology allows for standardizing HLA antibody and DSA detection. The study emphasizes the need for further research with real clinical data to validate and refine this approach.
(© 2024 The Author(s). European Journal of Immunology published by Wiley‐VCH GmbH.)
Databáze: MEDLINE
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