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

Abstract

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. simplexproducts