Abstract text (incl. figure legends and references)

Questions: A close association between migraine and allergic diseases has been reported. IgE and mast cells play key roles in the development of allergic diseases. Tryptase has been used a marker of mast cell activation. Although altered levels of IgE in migraine was reported, no study separately evaluated the IgE and tryptase levels in episodic migraine (EM) and chronic migraine (CM).

Methods: The IgE and tryptase levels were measured by fluorescence enzyme immune assay method on a ThermoFisher Phadia 250 system. We collected plasma ≥ 48 h having passed after the cessation of a typical migraine attack, being headache-free (for participants with EM), and having mild or less headache intensity (for participants with CM). We also evaluated the history of allergic disease among participants.

Results: This study enrolled 95 and 96 participants with EM and CM, respectively and 56 controls. 88 of participants (42, 40, and 8 of EM, CM and controls) had allergic diseases. Among participants with allergic diseases, IgE levels were significantly different among participants with EM, CM and controls (81.6 [42.0-248.3] vs. 46.5 [15.9-116.0] vs. 195.0 [78.2-301.0] KU/L, p=0.025). Nevertheless, tryptase levels did not significantly differ among three groups (3.4 [2.3-4.1] vs. 3.3 [2.3-4.2] vs. 3.7 [2.8-3.8] ng/ml, p=0.625). IgE levels among participant with allergic diseases, headache frequency was inversely associated with IgE levels (Pearson"s correlation coefficient = - 0.261, p=0.019). Among 109 participants without allergic diseases, IgE (43.5 [27.8-99.8] vs. 45.1 [23.2-99.0] vs. 50.7 [24.2-114.0] KU/L, p=0.832) and tryptase (3.4 [2.3-4.1] vs. 3.3 [2.7-3.9] vs. 3.3 [2.5-4.3] ng/ml, p=0.862) levels did not significantly differ among three groups.

Conclusions: IgE levels were significantly differ in participants with allergic diseases among those with EM, CM and controls.