Different Fish-Eating Habits and Cytokine Production in Chronic Urticaria with and without Sensitization against the Fish-Parasite Anisakis simplex

Background:Anisakis simplexsensitization has been associated with acute, but also with chronic urticaria.The objective of this study is to characterize chronic urticaria with (CU+) and without sensitization (CU-) againstthe ubiquitous fish parasiteA. simplexin a transversal and longitudinal evaluation.Methods:16 CU+ and 22 CU- patients were included and assessed for Urticaria activity score (UAS), fish-eating habits by standardized questionnaire and cytokine production (assessed by flow cytometric bead-basedarray) of peripheral blood mononuclear cells after stimulation withA. simplexextract or Concanavalin A (ConA). Patients were randomly put on a fish-free diet for three months and UAS, as well as cytokine productionwere again assessed. A difference of"1 in UAS was defined as improvement.Results:There was no difference in UAS in both groups.Anisakisinduced IL-2, IL-4 and IFN-γproduction washigher in CU+. Con A induced IL-6 and IL-10 production was higher in CU+. CU+ was associated with highertotal fish intake, whereas CU- was associated with oily fish intake. The correlation of UAS was positive with oilyfish, but negative with total fish intake.There was a better UAS-based prognosis in CU+ without diet. Improvement was associated with higher ConA induced IL-10!IFN-γas well as IL-10!IL-6 ratios. Further, previous higher oily fish intake was associated withimprovement.Conclusions:Our data confirm the different clinical and immunological phenotype of CU+. Our results show acomplex relationship between fish-eating habits, cytokine production and prognosis, which could have impor-tant consequences in dietary advice in patients with CU. When encounteringA. simplexsensitization, patientsshould not be automatically put on a diet without fish in order to reduce contact withA. simplexproductsThe study was funded by grants from Fundación Sociedad Española de Alergología e Inmunología Clínica (SEAIC) 2009 and Fundación Mutua Madrileña 2009, SpainS

Are fish tropomyosins allergens?

Universidad Complutense de MadridDepto. de Microbiología y ParasitologíaFac. de FarmaciaTRUEpu

Possible Allergenic Role of Tropomyosin in Patients with Adverse Reactions after Fish Intake

<p>In a recent case report, patient’s anti-fish tropomyosin IgE was associated with gastrointestinal symptoms. We aimed to demonstrate on a wider scale that the panallergen tropomyosin should not be limited to invertebrate species and that clinically relevant reactions could be elicited by vertebrate tropomyosin. On the whole, 19 patients with adverse reactions after fish intake and showing negative skin tests with commercial fish extracts were included. Fish tropomyosin was recognized by 10/19 patients’ IgE by immunoblotting. All patients with gastrointestinal complaints after fish intake (6/6) showed an IgE band matching with tropomyosin. Cod, albacore, and swordfish tropomyosins were recognized by most patients although 3/10 patients did not claim adverse reactions to these fish species. Immunoblotting with a battery of antigens from different fish species have a high yield of positivity at a band matching with tropomyosin molecular weight, even if they have not been claimed to be causative agents of symptoms. Tropomyosin is therefore a good candidate to be investigated as a clinically relevant fish allergen in patients who report adverse reactions after fish intake.</p

Possible Allergenic Role of Tropomyosin in Patients with Adverse Reactions after Fish Intake

In a recent case report, patient's anti-fish tropomyosin IgE was associated with gastrointestinal symptoms. We aimed to demonstrate on a wider scale that the panallergen tropomyosin should not be limited to invertebrate species and that clinically relevant reactions could be elicited by vertebrate tropomyosin. On the whole, 19 patients with adverse reactions after fish intake and showing negative skin tests with commercial fish extracts were included. Fish tropomyosin was recognized by 10/19 patients' IgE by immunoblotting. All patients with gastrointestinal complaints after fish intake (6/6) showed an IgE band matching with tropomyosin. Cod, albacore, and swordfish tropomyosins were recognized by most patients although 3/10 patients did not claim adverse reactions to these fish species. Immunoblotting with a battery of antigens from different fish species have a high yield of positivity at a band matching with tropomyosin molecular weight, even if they have not been claimed to be causative agents of symptoms. Tropomyosin is therefore a good candidate to be investigated as a clinically relevant fish allergen in patients who report adverse reactions after fish intake.Depto. de Microbiología y ParasitologíaFac. de FarmaciaTRUEpu