The impact of cross reactivity of anti-HLA-B27 monoclonal antibodies on flow cytometric HLA-B27 screening

Abstract HLA-B27 is a strong diagnostic biomarker as it is found in 90– 95% of ankylosing spondylitis. Routinely, the false-positive results generated by cross-reactivity of HLA-B27 monoclonal antibodies (mAbs) with some other type of HLA-B antigens are problematic. The present study aims at improving the sensitivity and specificity of typing for HLA-B27 by using a more accurate DNA assay. A real time sequence specific primer polymerase chain reaction (PCR-SSP) is performed by using MGB TaqMan oligoprobe and an ABI PRISM™ 7500 sequence detection system. The TaqMan PCR-SSP assay is compared with Immunophenotyping by flow cytometric antigen assay (BD HLA-B27-Kit, clone GS145.2). The results are finally confirmed by sequencing (ABI PRISM ® 3100). As summarised in the table, three methods are identical for clearly positive and negative results. There is 90% concordance for borderline negative results obtained by immunophenotyping with TaqMan PCR-SSC and/or sequencing. However, only 15.4% of borderline positives obtained by immunophenotyping are confirmed as true HLA-B27 positives by sequencing as well as TaqMan PCR-SSC. TaqMan PCR-SSP DNA assay completely correlates with sequencing (gold standard) with 100% PPV and NPV, compared to a PPV of 15% and a NPV of 98% for borderline results by immunophenotyping. Conclusion: when compared with flow cytometric antigen assay, typing HLA-B27 by TaqMan PCR-SSP clearly demonstrates an advantage to better establish the genotype of the patient. Specifically, there is a marked difference for ambitious positive results from immunophenotyping. Moreover, compared to immunophenotyping, there is no need of fresh samples, can test a larger number of samples concomitantly, and reduces technical time as well as cost. N = 52 Immunophenotyping TaqMan PCR-SSP Sequencing Immuno vs Sequencing TaqMan PCR-SSP vs Sequencing Positive 11 11 11 100% 100% Negative 17 17 17 100% 100% Positive (borderline by Immunophenotyping) 13 2 2 15% 100% Negative (borderline ) by Immunophenotyping) 10 9 9 98% 100%

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Flow cytometric analysis on cross-reactivity of human-specific CD monoclonal antibodies with splenocytes of Aotus nancymaae, a non-human primate model for biomedical research

Veterinary Immunology and Immunopathology ◽

10.1016/j.vetimm.2007.06.010 ◽

2007 ◽

Vol 119 (1-2) ◽

pp. 14-20 ◽

Cited By ~ 4

Author(s):

Claudia A. Daubenberger ◽

Rolf Spirig ◽

Manuel E. Patarroyo ◽

Gerd Pluschke

Keyword(s):

Monoclonal Antibodies ◽

Biomedical Research ◽

Flow Cytometric Analysis ◽

Cross Reactivity ◽

Primate Model ◽

Flow Cytometric ◽

Human Primate ◽

Human Specific

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Development of a Colloidal Gold Immunochromatographic Assay for Duck Enteritis Virus Detection Using Monoclonal Antibodies

Pathogens ◽

10.3390/pathogens10030365 ◽

2021 ◽

Vol 10 (3) ◽

pp. 365

Author(s):

Fengli Liu ◽

Yanxin Cao ◽

Maokai Yan ◽

Mengxu Sun ◽

Qingshui Zhang ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Colloidal Gold ◽

Preventive Intervention ◽

Virus Detection ◽

Cross Reactivity ◽

Duck Enteritis Virus ◽

Detection Sensitivity ◽

Immunochromatographic Assay ◽

Efficient Detection ◽

Enteritis Virus

Duck viral enteritis is a highly contagious and fatal disease of commercial waterfowl flocks. The disease occurs sporadically or epizootically in mainland China due to insufficient vaccinations. Early and rapid diagnosis is important for preventive intervention and the control of epizootic events in clinical settings. In this study, we generated two monoclonal antibodies (MAbs) that specifically recognized the duck enteritis virus (DEV) envelope glycoprotein B and tegument protein UL47, respectively. Using these MAbs, a colloidal gold-based immunochromatographic assay (ICA) was developed for the efficient detection of DEV antigens within 15 min. Our results showed that the detection limit of the developed ICA strip was 2.52 × 103 TCID50/mL for the virus infected cell culture suspension with no cross-reactivity with other pathogenic viruses commonly encountered in commercially raised waterfowl. Using samples from experimentally infected ducks, we demonstrated that the ICA detected the virus in cloacal swab samples on day three post-infection, demonstrating an 80% concordance with the PCR. For tissue homogenates from ducks succumbing to infection, the detection sensitivity was 100%. The efficient and specific detection by this ICA test provides a valuable, convenient, easy to use and rapid diagnostic tool for DVE under both laboratory and field conditions.

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Monoclonal antibodies to bovine UDP-galactosyltransferase. Characterization, cross-reactivity, and utilization as structural probes.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)57498-1 ◽

1986 ◽

Vol 261 (17) ◽

pp. 7975-7981

Author(s):

J T Ulrich ◽

J R Schenck ◽

H G Rittenhouse ◽

N L Shaper ◽

J H Shaper

Keyword(s):

Monoclonal Antibodies ◽

Cross Reactivity ◽

Structural Probes

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THU0389 OBESITY IS A STRONG PREDICTOR OF WORSE CLINICAL OUTCOMES AND TREATMENT RESPONSES TO BIOLOGICS IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.4445 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 429.2-429

Author(s):

L. Hu ◽

X. Ji ◽

F. Huang

Keyword(s):

Ankylosing Spondylitis ◽

Disease Activity ◽

Clinical Outcomes ◽

Normal Weight ◽

Low Grade ◽

Hla B27 ◽

Treatment Responses ◽

The Impact ◽

Overweight Or Obesity

Background:Obesity population are rising rapidly and have become a major health issue. Studies have shown that obesity is a low-grade inflammatory status characterized by increase in proinflammatory cytokines.Objectives:To examine the impact of overweight or obesity on disease activity and treatment responses to biologics in patients with ankylosing spondylitis (AS) in a real-world setting.Methods:Body mass index (BMI) is available in 1013 patients from the Chinese Ankylosing Spondylitis Imaging Cohort (CASPIC). Differences in clinical outcomes (such as BASDAI, ASDAS, BASFI, and ASAS HI) and treatment responses to biologics (ΔBASDAI and ΔASDAS) over 3, 6, 9, and 12 months are assessed between BMI categories (normal weight BMI <24 kg/m2; overweight BMI=24-28 kg/m2; obesity BMI ≥28 kg/m2) using Kruskal-Wallis test. The association between BMI and clinical characteristics and treatment responses to biologics was determined, and multivariate median regression analyses were conducted to adjust for confounders (such as age, gender, smoke, and HLA-B27).Results:Among 1013 patients with AS, overweight accounts for 33%, while obesity for 12.4%. There were significant differences between patients who were obese or overweight and those with a normal weight regarding clinical outcomes (BASDAI: 2.90/2.56 vs 2.21; ASDAS-CRP: 2.20/1.99 vs 1.81; BASFI: 2.13/1.69 vs 1.38; ASAS HI: 6.87/5.29 vs 5.12 and BASMI: 2.35/1.76 vs 1.62; all P<0.05). After adjusting for age, gender, smoke, and HLA-B27, obesity remained associated with higher disease activity (BASDAI: β=0.55, P=0.005; ASDAS-CRP: β=0.40, P<0.001), poorer functional capacity (BASFI: β=0.58, P=0.001), worse health index (ASAS HI: β=1.92, P<0.001) and metrology index (BASMI: β=0.71, P=0.013). For TNFi users, BMI was found to be negatively correlated with changes in disease activity (ΔBASDAI and ΔASDAS) in the multivariate regression model (all P<0.05), and overweight and obese patients showed an unsatisfactory reduction in disease activity during 3-month, 6-month, 9-month, and 12-month follow-up period, compared to normal weight patients (all P<0.05).Conclusion:Overweight or obesity impacts greatly on clinical outcomes and treatment responses to biologics in patients with ankylosing spondylitis, which argues strongly for obesity management to become central to prevention and treatment strategies in patients with AS.References:[1]Maachi M, Pieroni L, Bruckert E, et al. Systemic low-grade inflammation is related to both circulating and adipose tissue TNFalpha, leptin and IL-6 levels in obese women. Int J Obes Relat Metab Disord 2004;28:993–7.Figure 1.Changes of disease activity for TNFi users during 3-, 6-, 9- and 12-month follow-up according to BMI categories. a: vs. normal weight, P<0.05 in 3 months; b: vs. normal weight, P<0.05 in 6 months; c: vs. normal weight, P<0.05 in 9 months; d: vs. normal weight, P<0.05 in 12 months.Acknowledgments:We appreciate the contribution of the present or former members of the CASPIC study group.Disclosure of Interests:None declared

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The Impact on Infectivity and Neutralization Efficiency of SARS-CoV-2 Lineage B.1.351 Pseudovirus

Viruses ◽

10.3390/v13040633 ◽

2021 ◽

Vol 13 (4) ◽

pp. 633

Author(s):

Yeong Jun Kim ◽

Ui Soon Jang ◽

Sandrine M. Soh ◽

Joo-Youn Lee ◽

Hye-Ra Lee

Keyword(s):

South Africa ◽

Monoclonal Antibodies ◽

Cell Fusion ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Receptor Binding Domain ◽

Viral Spread ◽

New Variant ◽

Global Concern ◽

The Impact

A new variant of SARS-CoV-2 B.1.351 lineage (first found in South Africa) has been raising global concern due to its harboring of multiple mutations in the spike that potentially increase transmissibility and yield resistance to neutralizing antibodies. We here tested infectivity and neutralization efficiency of SARS-CoV-2 spike pseudoviruses bearing particular mutations of the receptor-binding domain (RBD) derived either from the Wuhan strains (referred to as D614G or with other sites) or the B.1.351 lineage (referred to as N501Y, K417N, and E484K). The three different pseudoviruses B.1.351 lineage related significantly increased infectivity compared with other mutants that indicated Wuhan strains. Interestingly, K417N and E484K mutations dramatically enhanced cell–cell fusion than N501Y even though their infectivity were similar, suggesting that K417N and E484K mutations harboring SARS-CoV-2 variant might be more transmissible than N501Y mutation containing SARS-CoV-2 variant. We also investigated the efficacy of two different monoclonal antibodies, Casirivimab and Imdevimab that neutralized SARS-CoV-2, against several kinds of pseudoviruses which indicated Wuhan or B.1.351 lineage. Remarkably, Imdevimab effectively neutralized B.1.351 lineage pseudoviruses containing N501Y, K417N, and E484K mutations, while Casirivimab partially affected them. Overall, our results underscore the importance of B.1.351 lineage SARS-CoV-2 in the viral spread and its implication for antibody efficacy.

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