What Do We Know About Fish Allergy at the End of the Decade?

Fish allergy is one of the most common food allergies. It is usually considered to be IgE-mediated and correlates well with diagnostic tests such as prick tests and/or determination of specific IgE. Avoidance is the recommended treatment and is generally extended to all fish species. However, new clinical presentations have been described. These include non-IgE-mediated disease, monosensitization, and new syndromes that are sometimes associated, surprisingly, with cross-reactivity. Advances in molecular allergy have provided insights into new allergens and have increased our understanding of cross-reactivity. This paper focuses on recent publications providing information for clinicians involved in the management of fish allergy.

Pigeon tick bite: A neglected cause of idiopathic nocturnal anaphylaxis.

Anaphylaxis is a serious systemic allergic reaction with rapid onset and potentially life-threatening. We report in detail a case of severe nocturnal anaphylaxis due to pigeon tick bite showing the diagnostic value of the extract and the recombinant allergen in the diagnostic procedures (basophil activation test, IgE immunoblot, and experimental ImmunoCAP). Apart from the presented case, we describe that during the last 10 years, we have collected 28 cases of allergy to Argas reflexus from several European countries. We suspect that this allergy is underdiagnosed because of the lack of diagnostic reagents. Because of the growing number of pigeons in Middle and Southern Europe cities, some cases of idiopathic anaphylaxis could potentially be caused by A. reflexus in those countries. The identification of pigeon ticks as a trigger of anaphylaxis would greatly improve medical care and advice for these patients as the parasite can be exterminated by eradication measures to avoid further incidents.

Cross-reactivity to fish and chicken meat - a new clinical syndrome.

BACKGROUND: Fish is one of the most allergenic foods. While clinical cross-reactivity among different fishes is a widely accepted feature of fish allergy, associations with other food allergies are not well understood. This study aims at analyzing the relevance of clinical cross-reactivity between fish and chicken meat in patients with allergy to chicken meat without sensitization to hen's eggs. METHODS: Patients with food allergy to fish and chicken meat (n = 29) or chicken meat only (n = 7) were recruited. IgE-reactive chicken proteins were identified (Edman, MS analysis) and quantified (ELISA). Allergens were used in IgE ELISA and skin testing. RESULTS: Chicken parvalbumin and two new allergens, aldolase and enolase, were identified at 12, 40, and 50 kDa, respectively. They were recognized by sIgE of 61%, 75%, and 83% of all patient sera which were in the majority of the cases positive for the fish homologues as well. Fish and chicken meat allergens were highly cross-reactive while high inhibition rates with fish or chicken allergens correlated with the patients' primary sensitization to fish or chicken. In cooked or roasted foods, enolase and aldolase were detectable in chicken breast while parvalbumin was detectable in chicken legs and wings. CONCLUSIONS: Fish and chicken meat are cross-reactive foods; both fish-allergic and chicken meat-allergic patients might be at risk of developing a food allergy to chicken meat or to fish, respectively. This clinical phenomenon is proposed to be termed 'fish-chicken syndrome' with cross-reactive allergens involved being parvalbumins, enolases, and aldolases.

[The diagnosis of food allergies]. / La mise au point des allergies alimentaires.

The prevalence of food allergies is more than 5 %, rising currently. The clinical presentations are polymorphic and involve the skin, respiratory, vascular and gut systems. The diagnosis is based on the consistancy between the allergic history and the results of the specific IgE investigations. When the relationship between the history and the IgE sensitization is not significant, an oral challenge test with food is indicated under supervision of a reference center. New approach, based on dosage of specific IgE to different constituent (recombinant protein) of each allergen, can predict the severity of the reaction and the cross reactivity between allergens, in some patients.

[Diagnosis of allergy in asthma]. / Le diagnostic de l'allergie dans l'asthme.

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.

Limited cross reactivity among arginine kinase allergens from mealworm and cricket edible insects.

Insects are seen as a solution to the increasing demand for protein sources for food. However, entomophagy has unfortunately been linked to allergic reactions in Europe with people with professional contacts. As mealworms (Tenebrio molitor) and crickets (Acheta domesticus) have recently become commercially available (both whole or in food formulation) in several European countries, this research assessed the cross allergenicity of arginine kinase (AK). Based on the collection of sera from a entomology laboratory staff, oven cooked insects but also purified AK fractions were tested. Immunoblotting against the protein extracts revealed different Immunoglobulin E reactivity of sera according to the insect target species: two bands (40 and 14 kDa) for crickets and a pattern including light responses at 17, 25 and 37 kDa for mealworms. Focusing on AK, low specific allergenicity was here illustrated and discussed in relation to the development of a safe edible insect consumption by humans.

[The usefulness of nasal provocation tests for respiratory physicians]. / Intérêt des tests de provocation nasale pour le pneumologue.

Rhinitis and asthma are common diseases that are strongly linked from both the epidemiological and patho-physiological point of view. A precise aetiological diagnosis is required in order to optimize treatment. Nasal provocation tests (NPT) determine precisely the role of the allergen in the initiation of the symptoms of rhinitis particularly when the history does not produce convincing evidence of the clinical relevance of an allergen. It may also have important consequences for the choice of an allergenic immunotherapy. NPT are not standardized but simple methods based on international recommendations provide us with good diagnostic accuracy. In this paper, we will discuss the practical aspects of NPT as well as the clinical or research situations where they may be useful for the respiratory physician.

[Rheumatoid arthritis and cystic fibrosis]. / Polyarthrite rhumatoïde et mucoviscidose.

INTRODUCTION: Inflammatory arthropathies are rare complications of cystic fibrosis (CF). We describe three cases of rheumatoid arthritis (RA) occurring in patients with this disease. OBSERVATIONS: Among the 100 patients under the care of the adult CF centre in Lille 3 presented with RA. This developed at the ages of 17, 44 and 19 years with a FEV1 of 53%, 42% and 94% respectively. They were 2 women and 1 man, with CFTR gene mutation delta F508 (1 homozygote and 2 heterozygotes) and positive sweat tests. They were colonised with Staphylococcus aureus, and rheumatoid factor and/or anti CCP antibodies were positive. The appearance and progression of RA were associated with exacerbations of bronchial infection and deterioration of respiratory function. In 2 patients the RA was continuously progressive despite intensive treatment involving high dose cortico-steroids, methotrexate (ineffective) followed by leflunomide (complicated by intractable respiratory infection). CONCLUSION: There is an increased incidence of RA in our patient population with CF. The new serum markers of RA including anti CCP are of diagnostic interest. The evolution of the two diseases is related and seems to be dependent on the level of infection leading to therapeutic problems.