Analysis of Ani s 7 and Ani s 1 allergens as biomarkers of sensitization and allergy severity in human anisakiasis

Serum IgA contributes to the comprehension of Anisakis simplex associated chronic urticaria

The phenotype of allergic diseases associated with Anisakis determines the pattern of cytokines related to antibody production. However, the role of serum IgA and the immunomodulatory mechanisms exerted by active infection of L3 or passive mucosal contact with A. simplex specific antigens has not been studied before. We measured serum cytokine by flow cytometry (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, IL-17A, TGF-β1) and antibody levels (IgE, IgG4, IgA) by ELISA against total and excretory-secretory (ES) antigens, Ani s 3,and the group of major allergens Ani s 1, Ani s 7, and Ani s 13 in sera from 10 patients with gastro-allergic anisakiasis (GAA), 11 Anisakis sensitization associated chronic urticaria (CU+) as well as 17 non-Anisakis-sensitized patients with chronic urticaria (CU-), compared with the urticaria control group (18 subjects). Specific IgE, IgG4 and IgA were high in the GAA, but IgA levels were significantly higher in the CU+ with respect the CONTROL group. We observed higher levels of the ratio IgA/IgG4 in CU+ than GAA group for Ani s 1, Ani s 7, Ani s 13 and ES. Furthermore, chronic urticaria (CU) patients showed significant lower levels of IL-10, IFN-γ and IL-17A than patients without CU. The anti-Ani s 13 IgA/IgG4 ratio correlated positively with pro-inflammatory cytokines and ratios (TNF-α, IL-17A, Th17/Th2, Type1/Type2 and TNF-α/IL-10) in CONTROL group. In general, Anti-Anisakis IgA/G4 ratio was high in CU patients. In conclusion, this study demonstrates the importance of serum IgA because it is associated with chronic urticaria independently of Anisakis sensitization.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

IgE-mediated Anisakis allergy in children

Anisakids are nematodes responsible for different clinical patterns in humans. The well-known human-infecting Anisakis species include members of the Anisakis simplex (AS) complex. Humans usually contract anisakiasis through ingestion of raw or undercooked seafood containing Anisakis larvae. Once Anisakis has been ingested, patients may develop disease driven directly by Anisakis larvae and/or by allergic reaction due to this nematode. The capability of inducing allergic reactions depends on the expression of specific antigens by nematodes and host factors. This study aims to resume actual knowledge about AS and Anisakiasis with regard to epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment. Particular attention is paid to Anisakis allergens and their cross-reactivity on available diagnostic methods, and defining a diagnostic pathway for Anisakis allergy. Because only a few data are available in the literature about pediatric population, we focus on this group of patients specifically.

Anisakidae parasites in frozen fish fillets intended for human consumption

INTRODUCTION

Anisakiasis is a human parasitic disease caused by the consumption of raw fish or shellfish containing larvae of the Anisakidae family. It is currently considered an emerging disease of public health interest.

OBJECTIVE

To identify the presence of larvae of the Anisakidae family in samples of frozen raw fish fillets intended for human consumption in markets in Medellín and its metropolitan area in Antioquia, Colombia.

MATERIALS AND METHODS

A cross-sectional study was carried out, in which larvae of the Anisakidae family were detected and identified in frozen raw fish fillets from three representative markets in Medellín and its metropolitan area. A total of 384 ready for consumption fillets were analyzed (197 sawfish, 137 salmon, 37 tuna, and 13 hake), using the pressing and ultraviolet light method. Taxonomic keys were used to identify the collected parasites and to establish its genus. Conventional PCR and Sanger sequencing was performed to determine the species.

RESULTS

Four larvae were found in 4 of the 384 (1.04%) fillets (CI95% 1.04 ± 1.01%). The species of fish in which the larvae were found was sawfish (Scomberomorus spp.) and the genus and species of the larvae was established as Anisakis pegreffii.

CONCLUSIONS

According to the study, the presence of Anisakis parasites in frozen raw fish fillets in the influence area is evident.

Toxocara canis extract fractions promote mainly the production of Th1 and regulatory cytokines by human leukocytes in vitro

Helminths possibly down-modulate immune responses to airborne allergens through the induction of a regulatory network. The identification of helminths bioactive molecules is highly desirable, given their immunomodulatory potential which could be used in immunotherapies for allergy and autoimmune diseases. To investigate the immunoregulatory potential of the adult Toxocara canis crude extract and ten protein fractions of its extract, human peripheral blood mononuclear cells (PBMC) from 10 allergic and 9 non-allergic individuals were cultivated, in vitro, in the presence or absence of these antigens, and their supernatants were evaluated for cytokine production (TGF-β, IL-10, IL-12, TNF-α, IL-6, IL-5, IL13, and IL-17). To determine the cell viability, the PBMC were cultivated for 24 h in the presence of the antigens and, following, they were subjected to a cytotoxicity assay. The viability of the PBMC was not affected by incubation with the T. canis antigens. As some fractions stimulated the production of immunoregulatory (TGF-β and/or IL-10), IL-12 and Th1 (TNF-α) cytokines, without stimulating Th2 cytokines (IL-5 and IL13) and IL-17, it was proposed that they would be potential candidates for further studies, especially involving the purification and characterization of specific proteins, which could be tested separately to evaluate their specific role as adjuvants in immunotherapy for inflammatory diseases.

Molecular diagnosis contribution for personalized medicine

PURPOSE OF REVIEW

The purpose of the current review is to highlight the most recent findings in molecular allergy and its applicability in precision medicine for allergic patients.

RECENT FINDINGS

Molecular allergy provides useful information in areas of respiratory allergy (house dust mites, pet dander and pollen allergy), food allergy (tree nuts, peanuts, fruits and vegetables), hymenoptera venom allergy and others, in order to improve management of patients. Regional differences in sensitization profiles, assay characteristics and interpretation of molecular sensitization in relation to whole extracts and total immunoglobulin E need to be taken into account. Studies of the impact of such strategies are needed.

SUMMARY

Molecular allergy diagnosis represents a major contribution for personalized medicine. It aids in the assesment of risk prediction, disease severity, genuine/cross-reactive sensitization, and finally to apply precise management strategies.

Targeted proteomics and specific immunoassays reveal the presence of shared allergens between the zoonotic nematodes Anisakis simplex and Pseudoterranova decipiens

The family Anisakidae, mainly represented by Anisakis simplex s.l. and Pseudoterranova decipiens, encompasses zoonotic nematodes infecting many marine fish. Both are responsible for gastrointestinal disease in humans after ingestion of a live larva by consumption of undercooked fish, and, in the case of A. simplex, an allergic reaction may occur after consuming or even handling infected fish. Due to its phylogenetic relatedness with A. simplex, few studies investigated the allergenic potential of P. decipiens, yet none of them focused on its excretory/secretory (E/S) proteins that easily get missed when working solely on extracts from crushed nematodes. Moreover, these E/S allergens remain behind even when the larva has been removed during fish quality processing. Therefore, the aim was to investigate if Anisakis-like allergens could also be detected in both crushed and E/S P. decipiens protein extract using targeted mass spectrometry analysis and immunological methods. The results confirmed that at least five A. simplex allergens have homologous proteins in P. decipiens; a result that emphasizes the importance of also including E/S protein extracts in proteomic studies. Not only A. simplex, but also P. decipiens should therefore be considered a potential source of allergens that could lead to hypersensitivity reactions in humans.