Investigating complement mediated interference in class I HLA-specific antibodies following renal transplantation
| Autor: | Matthew Howse, D. Ridgway, Abdul Hammad, Chang Wong, Robert A. Bray, Petra Goldsmith, Steve Christmas, Howard M. Gebel, Andrew R. Jones, David Lowe, Sanjay Mehra |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Graft Rejection
Immunology Population Biotin Human leukocyte antigen 030230 surgery Cohort Studies Epitopes 03 medical and health sciences 0302 clinical medicine Bacterial Proteins HLA Antigens Isoantibodies Predictive Value of Tests Humans Immunology and Allergy Medicine education Edetic Acid Retrospective Studies Transplantation education.field_of_study biology business.industry Histocompatibility Testing Histocompatibility Antigens Class I Curve analysis Retrospective cohort study Complement System Proteins Prognosis Kidney Transplantation Specific antibody Renal transplant biology.protein Antibody business 030215 immunology |
| Zdroj: | Transplant Immunology |
| Popis: | Introduction Single antigen bead testing (SAB) for HLA-specific antibody enables efficient organ allocation and aids in the diagnosis of antibody mediated rejection. In this retrospective cohort study, a population of kidney transplant recipients possessing HLA Class I antibodies was used to evaluate the best method for resolving complement interference, the so called “prozone” effect. The aim was to compare the use of EDTA versus a Biotin-Streptavidin Complex as methodological approaches for abating the prozone effect using a fixed 1 in 10 dilution as validation. Methods One hundred and seventeen patients transplanted in our centre between 2009 and 2014 were identified as having class I HLA-specific antibody(−ies) using a Labscreen® Mixed assay. Positive sera underwent class I HLA-specific SAB testing; for comparison a standard SAB with and without EDTA, BSC and dilution (1 in 10) modifications were utilised. Samples were processed on the Luminex platform generating 11,349 bead reactions for analysis. Results We identified sera from 23 patients giving rise to 170 bead reactions showing complement interference. Using linear modelling, we observed slightly higher MFIs on average in both EDTA and BSC modifications when compared to the standard assay, allowing the nominal threshold MFI of 2000 in the standard assay to be adjusted to 2097 and 2033 in the EDTA and BSC assays respectively. We calculated 99% prediction intervals to establish outlier bead reactions for each assay. The 1 in 10 dilution was used as a crosscheck for determining which prozone reactions were overcome by EDTA and BSC. Using ROC curve analysis, EDTA was found to be ~90% sensitive and 100% specific compared to BSC which was ~60% sensitive and 100% specific in ameliorating prozone positive reactions at the thresholds defined by linear models. Discussion Our data indicates that both EDTA and BSC are suitable assays in overcoming CMI. We recommend that all clinical laboratories adopt a validated assay designed specifically to abrogate CMI for all potential renal transplant recipients, as the standard assay is inhibited in nearly 20% of a post-transplant cohort. |
| Databáze: | OpenAIRE |
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