Study of the cross-reactivity of fish allergens based on a questionnaire and blood testing

Au@Ag Core-Shell Nanoparticles for Colorimetric and Surface-Enhanced Raman-Scattering-Based Multiplex Competitive Lateral Flow Immunoassay for the Simultaneous Detection of Histamine and Parvalbumin in Fish

Foodborne allergies and illnesses represent a major global health concern. In particular, fish can trigger life-threatening food allergic reactions and poisoning effects, mainly caused by the ingestion of parvalbumin toxin. Additionally, preformed histamine in less-than-fresh fish serves as a toxicological alert. Consequently, the analytical assessment of parvalbumin and histamine levels in fish becomes a critical public health safety measure. The multiplex detection of both analytes has emerged as an important issue. The analytical detection of parvalbumin and histamine requires different assays; while the determination of parvalbumin is commonly carried out by enzyme-linked immunosorbent assay, histamine is analyzed by high-performance liquid chromatography. In this study, we present an approach for multiplexing detection and quantification of trace amounts of parvalbumin and histamine in canned fish. This is achieved through a colorimetric and surface-enhanced Raman-scattering-based competitive lateral flow assay (SERS-LFIA) employing plasmonic nanoparticles. Two distinct SERS nanotags tailored for histamine or β-parvalbumin detection were synthesized. Initially, spherical 50 nm Au@Ag core-shell nanoparticles (Au@Ag NPs) were encoded with either rhodamine B isothiocyanate (RBITC) or malachite green isothiocyanate (MGITC). Subsequently, these nanoparticles were bioconjugated with anti-β-parvalbumin and antihistamine, forming the basis for our detection and quantification methodology. Additionally, our approach demonstrates the use of SERS-LFIA for the sensitive and multiplexed detection of parvalbumin and histamine on a single test line, paving the way for on-site detection employing portable Raman instruments.

Cutting Edge Aquatic-Based Collagens in Tissue Engineering

Aquatic-based collagens have attracted much interest due to their great potential application for biomedical sectors, including the tissue engineering sector, as a major component of the extracellular matrix in humans. Their physical and biochemical characteristics offer advantages over mammalian-based collagen; for example, they have excellent biocompatibility and biodegradability, are easy to extract, and pose a relatively low immunological risk to mammalian products. The utilization of aquatic-based collagen also has fewer religious restrictions and lower production costs. Aquatic-based collagen also creates high-added value and good environmental sustainability by aquatic waste utilization. Thus, this study aims to overview aquatic collagen's characteristics, extraction, and fabrication. It also highlights its potential application for tissue engineering and the regeneration of bone, cartilage, dental, skin, and vascular tissue. Moreover, this review highlights the recent research in aquatic collagen, future prospects, and challenges for it as an alternative biomaterial for tissue engineering and regenerative medicines.

Identification of Potentially Tolerated Fish Species by Multiplex IgE Testing of a Multinational Fish-Allergic Patient Cohort

BACKGROUND

Although recent studies indicated that many fish-allergic patients may safely consume certain fish species, no clinical guidelines are available for identification of the exact species tolerated by specific patients.

OBJECTIVE

To investigate whether multiplex immunoglobulin E (IgE) testing reveals potentially tolerated fish through absence of IgE to parvalbumin (PV) and extracts from specific species.

METHODS

Sera from 263 clinically well-defined fish-allergic patients from Austria, China, Denmark, Luxembourg, Norway, and Spain were used in a research version of the ALEX² multiplex IgE quantification assay. Specific IgE to PVs from 10 fish species (9 bony and 1 cartilaginous), and to extracts from 7 species was quantified. The IgE signatures of individual patients and patient groups were analyzed using SPSS and R.

RESULTS

Up to 38% of the patients were negative to cod PV, the most commonly used molecule in fish allergy diagnosis. Forty-five patients (17%) tested negative to PVs but positive to the respective fish extracts, underlining the requirement for extracts for accurate diagnosis. Between 60% (Spain) and 90% (Luxembourg) of the patients were negative to PV and extracts from ray, a cartilaginous fish, indicating its potential tolerance. Up to 21% of the patients were negative to at least 1 bony fish species. Of the species analyzed, negativity to mackerel emerged as the best predictive marker of negativity to additional bony fish, such as herring and swordfish.

CONCLUSIONS

Parvalbumins and extracts from multiple fish species relevant for consumption should be used in fish-allergy diagnosis, which may help identify potentially tolerated species for individual patients.

Comparative Analysis of Glycosylation Affecting Sensitization by Regulating the Cross-Reactivity of Parvalbumins in Turbot (Scophthalmus maximus), Conger Eel (Conger myriaster) and Sea Bass (Micropterus salmoides)

Parvalbumin (PV) is the most common allergen in fish. Some patients with fish allergy are allergic to only one species of fish but are tolerant to others; however, the underlying mechanism has not been identified. This study showed that three types of glycated fishes' PV showed a similar decrease in immunoglobulin E (IgE) binding. Glycosylation could improve the simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) digestion resistance of fishes' PV. We also discovered that the cross-reactivity between eel and turbot was weaker than that of bass; glycosylation can reduce cross-reactivity between eel/bass and turbot by downregulating Th2 cytokines and upregulating Th1 cytokines as well as downregulating the expression of G-T PV, G-E PV, G-B PV of IL-4 (94.31 ± 3.16, 73.26 ± 0.91, 94.95 ± 3.03 ng/mL), and IL-13 (38.84 ± 0.75, 33.77 ± 0.71, 36.51 ± 0.50 ng/mL) and upregulating the expression of IFN-γ (318.01 ± 3.46, 387.15 ± 3.30, 318.01 ± 4.21 ng/mL) compared with T PV, respectively. This study showed that glycosylation affected sensitization by regulating the cross-reactivity of parvalbumins.

Evaluation of Allergic Cross-Reactivity Among Fishes by Microfluidic Chips and MALDI-TOF MS

Fish is one of the most common foods that cause allergic reactions. The study of cross-reactivity among fishes using mass spectrometry (MS) is still limited. We developed a strategy using microfluidic chips coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to evaluate cross-reactivity among fishes. The protocol employed commercial magnetic beads functionalized with anti-human IgE antibodies to carry out the IgEs immunomagnetic separation in blood samples, followed by the capture of allergens from seafood protein extracts in a single-straight microfluidic channel. After elution, the captured allergens were digested and identified by MALDI-TOF MS and high-performance liquid chromatography-tandem mass spectrometry and validated by enzyme-linked immunosorbent assay (ELISA). An investigation of the reproducibility revealed that the protocol can sense well the allergens in a food matrix. Seven fish species were analyzed to evaluate the allergic cross-reactivity among fishes. The commercial ELISA test gave consistent results with the presently developed strategy when the same allergenicity test was performed. Parvalbumins were detected from five of the seven analyzed fishes. The sequence alignment of parvalbumins revealed that the similarity of parvalbumins identified from the analyzed fishes is larger than 64%. Boiling may reduce the allergenicity of fish, as demonstrated by a marginal diminish in the parvalbumin content of crucian carp (Carassius carassius) muscle when boiling with water. The method can potentially be used to predict allergic cross-reactivity among fish species, provide advice and guidance to individuals with a history of seafood allergy, and ensure food safety in the food allergy community.

A comprehensive overview of emerging processing techniques and detection methods for seafood allergens

Seafood is rich in nutrients and plays a significant role in human health. However, seafood allergy is a worldwide health issue by inducing adverse reactions ranging from mild to life-threatening in seafood-allergic individuals. Seafood consists of fish and shellfish, with the major allergens such as parvalbumin and tropomyosin, respectively. In the food industry, effective processing techniques are applied to seafood allergens to lower the allergenicity of seafood products. Also, sensitive and rapid allergen-detection methods are developed to identify and assess allergenic ingredients at varying times. This review paper provides an overview of recent advances in processing techniques (thermal, nonthermal, combined [hybrid] treatments) and main allergen-detection methods for seafood products. The article starts with the seafood consumption and classification, proceeding with the prevalence and symptoms of seafood allergy, followed by a description of biochemical characteristics of the major seafood allergens. As the topic is multidisciplinary in scope, it is intended to provide information for further research essential for food security and safety.

Clinical Relevance of Cross-Reactivity in Food Allergy

The diagnosis and management of food allergy is complicated by an abundance of homologous, cross-reactive proteins in edible foods and aeroallergens. This results in patients having allergic sensitization (positive tests) to many biologically related foods. However, many are sensitized to foods without exhibiting clinical reactivity. Although molecular diagnostics have improved our ability to identify clinically relevant cross-reactivity, the optimal approach to patients requires an understanding of the epidemiology of clinically relevant cross-reactivity, as well as the food-specific (degree of homology, protein stability, abundance) and patient-specific factors (immune response, augmentation factors) that determine clinical relevance. Examples of food families with high rates of cross-reactivity include mammalian milks, eggs, fish, and shellfish. Low rates are noted for grains (wheat, barley, rye), and rates of cross-reactivity are variable for most other foods. This review discusses clinically relevant cross-reactivity related to the aforementioned food groups as well as seeds, legumes (including peanut, soy, chickpea, lentil, and others), tree nuts, meats, fruits and vegetables (including the lipid transfer protein syndrome), and latex. The complicating factor of addressing co-allergy, for example, the risks of allergy to both peanut and tree nuts among atopic patients, is also discussed. Considerations for an approach to individual patient care are highlighted.

Review of New Trends in the Analysis of Allergenic Residues in Foods and Cosmetic Products

BACKGROUND

Allergies represent an important health problem in industrialized countries. Allergen sensitization is an important risk factor for the development of allergic diseases; thus, the identification of an individual's allergen sensitization is essential for the diagnosis and treatment of diseases.

OBJECTIVE

This review compares different modern methods applied for the analysis of allergens in various matrices (from 2015 to the end of September 2019).

CONCLUSIONS

Immunological methods are still most frequently used for detection of allergens. These methods are sensitive, but the lack of specificity and cross-reaction of some antibodies can still be a relevant source of errors. DNA-based methods are fast and reliable for determination of protein allergens, but the epitopes of protein allergens with posttranslational modifications and their changes, originated during various processing, cannot be identified through the use of this method. Methods based on application of biosensors are very rapid and easy to use, and can be readily implemented as screening methods to monitor allergens. Recent developments of new high-resolution MS instruments are encouraging and enable development in the analysis of allergens. Fast, very sensitive, reliable, and accurate detection and quantification of allergens in complex samples can be used in the near future. Mass spectrometry coupled with LC, GC, or electrophoretic methods bring additional advances in allergen analysis. The use of LC-MS or LC-MS/MS for the quantitative detection of allergens in various matrices is at present gaining acceptance as a protein-based confirmatory technique over the routinely performed enzyme-linked immunosorbent assays.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

Basophil Activation Test Based on CD203c Expression in the Diagnosis of Fish Allergy

Purpose

The basophil activation test (BAT) has been reported to be useful for the diagnosis of various food allergies, such as allergy to peanut, but not to fish. This study aimed to evaluate the diagnostic performance of the BAT for fish allergy.

Methods

We performed a retrospective review of patients with fish allergy who underwent the BAT using a panel of fish extracts (15 kinds) to examine the differential reactivity to several species of fish. The BAT score for each extract was expressed as the ratio of CD203c^high% with the extract to that with anti-IgE antibody. Clinical reactivity to each fish was confirmed by positive oral food challenge or a typical history of fish-induced immediate allergy symptoms. Receiver-operating-characteristic (ROC) analysis was performed to evaluate the diagnostic performance.

Results

Fifty-one patients with fish allergy were analyzed. Using extracts of 15 species of fish, the BAT was performed a total of 184 times on the patients. Clinical allergy to each species of fish was confirmed in 90 (48.9%) of those tests. ROC analysis yielded high areas under the curve for the BAT scores for the 5 most common fish species (0.72–0.88). The diagnostic accuracy ranged from 0.74 to 0.86. Using a tentative cutoff value of 0.3 deduced from the ROC analyses of the 5 fish species, the accuracy for other fish allergic reactions was generally high (0.6–1.0), except the fish tested in a small number of patients.

Conclusions

The BAT score based on CD203c expression may be useful for fish allergy diagnosis, especially since a large variety of fish can be tested by the BAT using fish extracts prepared by a simple method.

Fish Allergy Management: From Component-Resolved Diagnosis to Unmet Diagnostic Needs

Purpose of review

Fish is a common elicitor of IgE-mediated food allergy. Fish includes a large variety of foods, in terms of species and food processing, with marked distinction in local diets around the globe. Fish-allergic patients present with phenotypic diversity and major differences in levels of clinical cross-reactivity, features that pose an important challenge for the clinical diagnosis and management.

Recent findings

Parvalbumin is the major fish allergen. However, a single molecule is not sufficient but several homologs, allergens different from parvalbumin and allergen extracts, are needed for IgE-based diagnosis.

Summary

Parvalbumin-specific IgE are markers for clinical cross-reactions. Added value is provided by IgE typing to parvalbumin homologs from distantly related fish. IgE co-sensitization profiles (parvalbumin, enolase, aldolase) are referred as severity markers. The allergen panel seems to be not yet complete why fish extracts still play a crucial role in serum IgE analysis. Further clinical validation of a multiplex approach in molecular fish allergy diagnosis is needed for striving to avoid unnecessary food restrictions and in a further sense, improved patient care.

Patients Allergic to Fish Tolerate Ray Based on the Low Allergenicity of Its Parvalbumin

Background

Clinical reactions to bony fish species are common in patients with allergy to fish and are caused by parvalbumins of the β-lineage. Cartilaginous fish such as rays and sharks contain mainly α-parvalbumins and their allergenicity is not well understood.

Objective

To investigate the allergenicity of cartilaginous fish and their α-parvalbumins in individuals allergic to bony fish.

Methods

Sensitization to cod, salmon, and ray among patients allergic to cod, salmon, or both (n = 18) was explored by prick-to-prick testing. Clinical reactivity to ray was assessed in 11 patients by food challenges or clinical workup. IgE-binding to β-parvalbumins (cod, carp, salmon, barramundi, tilapia) and α-parvalbumins (ray, shark) was determined by IgE-ELISA. Basophil activation tests and skin prick tests were performed with β-parvalbumins from cod, carp, and salmon and α-parvalbumins from ray and shark.

Results

Tolerance of ray was observed in 10 of 11 patients. Prick-to-prick test reactions to ray were markedly lower than to bony fish (median wheal diameter 2 mm with ray vs 11 mm with cod and salmon). IgE to α-parvalbumins was lower (median, 0.1 kU/L for ray and shark) than to β-parvalbumins (median, ≥1.65 kU/L). Furthermore, α-parvalbumins demonstrated a significantly reduced basophil activation capacity compared with β-parvalbumins (eg, ray vs cod, P < .001; n = 18). Skin prick test further demonstrated lower reactivity to α-parvalbumins compared with β-parvalbumins.

Conclusions

Most patients allergic to bony fish tolerated ray, a cartilaginous fish, because of low allergenicity of its α-parvalbumin. A careful clinical workup and in vitro IgE-testing for cartilaginous fish will improve patient management and may introduce an alternative to bony fish into patients’ diet.

Seafood allergy: A comprehensive review of fish and shellfish allergens

Seafood refers to several distinct groups of edible aquatic animals including fish, crustacean, and mollusc. The two invertebrate groups of crustacean and mollusc are, for culinary reasons, often combined as shellfish but belong to two very different phyla. The evolutionary and taxonomic diversity of the various consumed seafood species poses a challenge in the identification and characterisation of the major and minor allergens critical for reliable diagnostics and therapeutic treatments. Many allergenic proteins are very different between these groups; however, some pan-allergens, including parvalbumin, tropomyosin and arginine kinase, seem to induce immunological and clinical cross-reactivity. This extensive review details the advances in the bio-molecular characterisation of 20 allergenic proteins within the three distinct seafood groups; fish, crustacean and molluscs. Furthermore, the structural and biochemical properties of the major allergens are described to highlight the immunological and subsequent clinical cross-reactivities. A comprehensive list of purified and recombinant allergens is provided, and the applications of component-resolved diagnostics and current therapeutic developments are discussed.

Diagnosis of Allergy to Mammals and Fish: Cross-Reactive vs. Specific Markers

PURPOSE OF REVIEW

Allergen extracts are still widely used in allergy diagnosis as they are regarded as sensitive screening tools despite the fact that they may lack some minor allergens. Another drawback of extracts is their low specificity, which is due to the presence of cross-reactive allergens. Progress in allergen identification has disclosed a number of allergenic molecules of homologous sequence and structure which are present in different animal species. This review summarizes recent advances in mammalian and fish allergen identification and focuses on their clinical relevance.

RECENT FINDINGS

Serum albumins and parvalbumins are well-known animal panallergens. More recently several members of the lipocalin family were found to be cross-reactive between furry animals whereas in fish, additional allergens, enolase, aldolase and collagen, were found to be important and cross-reactive allergens. New epidemiological studies have analysed the prevalence and clinical relevance of mammalian and fish components. Primary sensitization can be distinguished from cross-sensitization by using marker allergens. Although substantial progress has been made in allergen identification, only few markers are commercially available for routine clinical practice.

Allergenicity of bony and cartilaginous fish - molecular and immunological properties

Allergy to bony fish is common and probably increasing world-wide. The major heat-stable pan-fish allergen, parvalbumin (PV), has been identified and characterized for numerous fish species. In contrast, there are very few reports of allergic reactions to cartilaginous fish despite widespread consumption. The molecular basis for this seemingly low clinical cross-reactivity between these two fish groups has not been elucidated. PV consists of two distinct protein lineages, α and β. The α-lineage of this protein is predominant in muscle tissue of cartilaginous fish (Chondrichthyes), while β-PV is abundant in muscle tissue of bony fish (Osteichthyes). The low incidence of allergic reactions to ingested rays and sharks is likely due to the lack of molecular similarity, resulting in reduced immunological cross-reactivity between the two PV lineages. Structurally and physiologically, both protein lineages are very similar; however, the amino acid homology is very low with 47-54%. Furthermore, PV from ancient fish species such as the coelacanth demonstrates 62% sequence homology to leopard shark α-PV and 70% to carp β-PV. This indicates the extent of conservation of the PV isoforms lineages across millennia. This review highlights prevalence data on fish allergy and sensitization to fish, and details the molecular diversity of the two protein lineages of the major fish allergen PV among different fish groups, emphasizing the immunological and clinical differences in allergenicity.

Allergy to fish collagen: Thermostability of collagen and IgE reactivity of patients' sera with extracts of 11 species of bony and cartilaginous fish

BACKGROUND

Parvalbumin was identified as a major fish allergen, and has been well investigated. Collagen was identified as a second allergen; however, its allergenic properties remain uncharacterized. Although fish is an important staple in coastal countries, its thermostability is unknown. Therefore, we aimed to determine the thermostability of fish collagen as an allergen.

METHODS

Meat of seven bony and four cartilaginous fishes was heated at various temperatures and times, and extracts were analyzed using SDS-PAGE, IgE-ELISA, and SPTs.

RESULTS

Collagen was dissolved from heated meat of Pacific mackerel into a crude extract. Collagen in the extracts was degraded at a high heating load-140 °C (10 min) or 100 °C (320 min). However, ELISA revealed the IgE reactivities of patients' sera with the extracts were unchanged even after heating the samples. Patients strongly reacted to extract proteins of other bony fish, which were detected by patients' IgE even after heating at 100 °C (320 min). In contrast, reactivities of the extracts of cartilaginous fish were lower than those of bony fish. SPTs in one patient revealed that all bony and cartilaginous fish extracts prepared from heated meat elicited allergic reactions.

CONCLUSIONS

The IgE reactivity of patients' sera to fish collagen in extracts was retained even when fish meat was treated by a high heating load. As for the fish collagen, the IgE reactivities to cartilaginous fish were lower than that to bony fish. Reducing IgE reactivity to fish meat using heat is difficult, and other modalities will be required to produce hypoallergenic fish meat.

Fish allergy in patients with parvalbumin-specific immunoglobulin E depends on parvalbumin content rather than molecular differences in the protein among fish species

Allergenic characteristics of purified parvalbumins from different fish species have not been thoroughly investigated. We revealed that purified parvalbumins from nine different fish species have identical IgE-reactivities and high cross-reactivities. We also showed that fish allergenicity is associated with the parvalbumin content of the fish species, rather than species-specific differences in the molecular characteristics of the individual parvalbumin proteins.