Search results for "cross-reactivity"

Mortality in COVID-19 disease patients: Correlating Association of Major histocompatibility complex (MHC) with severe acute respiratory syndrome 2 (S…

2020

Highlights • In addition to ethnicity, socio-economic factors, prior vaccinations and exposure to other coronaviruses, other factors need to be considered to explain geographical and regional variations in susceptibility, severity of clinical expression of COVID-19 disease and outcomes. • Differences in peptide binding of SARS-CoV-2 variants to MHC class II, but not to MHC class I alleles frequent in individuals with African, Asian or Caucasian descent could be identified. • Single mutations in the wildtype of SARS-CoV-2, the so called B strain or L strain impact on MHC presentation • Most likely there is selective pressure from MHC class II alleles in regard to binding of the ORF8 (L84S) v…

Development of a Peptide-Based Sandwich Elisa for Human Tissue Prokallikrein with No Cross-Reactivity from Mature Kallikrein

2000

Human tissue prokallikrein is the enzymatically inactive zymogen of a serine proteinase involved in the liberation of vasoactive kinin peptides, and it is supposed that an impaired prokallikrein-to-kallikrein conversion is closely related to certain hypertensive and inflammatory disorders. Progress in understanding the biological role of the proenzyme has been limited by the absence of an accurate assay for the kallikrein precursor. We describe a sandwich enzyme-linked immunosorbent assay to measure human tissue prokallikrein using monospecific anti-peptide antibodies raised against propeptide derivatives. This method could detect a minimum concentration of 60 pg/ml prokallikrein and displa…

Use of a comprehensive diagnostic algorithm for Anisakis allergy in a high seroprevalence Mediterranean setting

2020

Summary Background.Diagnosis of anisakis allergy (AA) is based on the skin prick test (SPT) and specific IgE (sIgE) determination. Anyway, false positivity cases are due to cross reactivity with numerous allergens. The aim of the study was to evaluate the reliability of a comprehensive diagnostic algorithm for the AA. Methods.An observational study was conducted on a sample of consecutive subjects accessing the allergology outpatient ambulatories of two hospitals located in Western Sicily. All the recruited outpatients were tested by Skin Prick Test performed using anisakis extracts by ALK-Abello (Madrid, Spain). Specific IgE dosage for anisakis extracts was then performed by using ImmunoCA…

Isolated hevein-like domains, but not 31-kd endochitinases, are responsible for IgE-mediated in vitro and in vivo reactions in latex-fruit syndrome.

2005

Background Individuals with natural rubber latex allergy often have immediate reactions to plant-derived foods and fresh fruits, such as avocado and banana. IgE of these patients has been shown to bind endochitinases containing an N-terminal hevein-like domain (HLD). However, evidence on 31-kd endochitinase-induced reactions in vivo is lacking. Objective We sought to assess the clinical significance of 31-kd endochitinases and isolated HLDs in latex-fruit syndrome. Methods The 31-kd endochitinases and corresponding HLDs were purified or produced from avocado, banana, latex, and wheat germ. Skin prick test reactivities against purified proteins were examined in 15 patients with natural rubbe…

Evidence for the presence of functional protease activated receptor 4 (PAR4) in the rat colon

2004

Background and aims: Protease activated receptors (PARs) have been postulated to play a role during intestinal inflammation. The presence and role played by PAR4 in gastrointestinal functions have not been fully clarified. The aims of this study were: (i) to examine expression of PAR4 in rat proximal colon; (ii) to determine the mechanical effects induced by PAR4 activation in longitudinal muscle; and (iii) to characterise the underlying mechanisms. Methods: PAR4 expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. Mechanical activity was recorded as changes in isometric tension. Results: A PCR product corresponding to the predicted…

Cross-reactivity of a pathogenic autoantibody to a tumor antigen in GABA(A) receptor encephalitis

2021

Encephalitis associated with antibodies against the neuronal gamma-aminobutyric acid A receptor (GABA A -R) is a rare form of autoimmune encephalitis. The pathogenesis is still unknown but autoimmune mechanisms were surmised. Here we identified a strongly expanded B cell clone in the cerebrospinal fluid of a patient with GABA A -R encephalitis. We expressed the antibody produced by it and showed by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry that it recognizes the GABA A -R. Patch-clamp recordings revealed that it tones down inhibitory synaptic transmission and causes increased excitability of hippocampal CA1 pyramidal neurons. Thus, the antibody likely contributed to…

Evidence for auto-reactivity against the collectins, SP-A and MBL, in rheumatoid arthritis synovial fluids: Lack of cross-reactivity with C1q or type…

1997

Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity

1996

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described…

Cross-Reactivity of Epstein-Barr Virus-Specific Immunoglobulin M Antibodies with Cytomegalovirus Antigens Containing Glycine Homopolymers

2001

ABSTRACTTimely and reliable detection of acute primary human cytomegalovirus (HCMV) infection is important in prenatal screening programs and for differential diagnosis of infectious mononucleosis-like disease. Enzyme-linked immunosorbent assays (ELISAs) based on HCMV proteins enable the sensitive detection of immunoglobulin M (IgM) antibodies during primary infection. However, concerns have been raised about possible cross-reactivities of the HCMV antigens used for the design of such ELISAs with IgM antibodies induced by Epstein-Barr Virus (EBV). In this study we investigated whether IgM antibodies generated during acute EBV infection reacted with recombinant HCMV antigens. Serum samples f…

Tropomyosin: A panallergen that causes a worldwide allergic problem

2021

Background: Panallergens are proteins that take part in key processes of organisms and, therefore, are ubiquitously distributed with highly conserved sequences and structures. One class of these panallergens is composed of the tropomyosins. The highly heat-stable tropomyosins comprise the major allergens in crustaceans and mollusks, which make them important food allergens in exposed populations. Tropomyosins are responsible for a widespread immunoglobulin E cross-reactivity among allergens from different sources. Allergic tropomyosins are expressed in many species, including parasites and insects. Methods: This panallergen class is divided, according to it capacity of induced allergic symp…