IgE receptor responsiveness of basophils in chronic inducible urticaria

Abstract

IntroductionChronic inducible urticaria (CIndU) is a subgroup of chronic urticaria induced by a specific stimulus. We evaluated basophil characteristics in patients with CIndU and compared with those in patients with chronic spontaneous urticaria (CSU) and healthy controls (HCs).MethodsBlood was collected from patients, and a basophil activation test (BAT) was performed. Basophil responsiveness and surface marker expression in patients with CIndU were compared with those in patients with CSU and HCs. For some patients with CIndU, blood was collected before and after wheals were induced. In these cases, we compared the responsiveness of basophils before and after the appearance of wheals.ResultHCs (n=23) and patients with CIndU (n=24) or CSU (n=38) were enrolled in the study. The degree of basophil activation at steady state in patients with CIndU was higher than in HCs. Basophil responsiveness via high-affinity IgE receptor (FcϵRI) stimulation with anti-IgE or anti-FcϵRI antibody in patients with CIndU was equivalent to that in HCs, and higher than that in patients with CSU. No abnormalities in IgE and FcϵRI expressions on the surface of basophils in patients with CIndU were observed. When we induced wheals in some patients with CIndU and performed a BAT before and after the appearance of wheals, no significant changes were found.ConclusionPeripheral blood basophils in CIndU were slightly activated at steady state, but no abnormalities in basophil responsiveness. In future, a higher number of cases should be enrolled to confirm the role of basophils and refine therapeutic targets for CIndU.

Basophil Characteristics as a Marker of the Pathogenesis of Chronic Spontaneous Urticaria in Relation to the Coagulation and Complement Systems

“…However, Vasagar et al reported that the elevation of CD63, but not CD69 and CD203c, on the surface of basophils [ 38 ]. Mizuno et al also reported that the expression of CD63 and CD203c on the surface of basophils are elevated compared to healthy donors [ 39 ]. Expression levels of degranulation/activation markers of basophils may change during cell preparation and timing of blood collection due to the migration of activated basophils to the dermis.…”

“…Plasma histamine level Increase [31] Spontaneous histamine release Increase [31,32] Plasma IgE level Increase [33,34] Expression level of FcεRI Increase [33,34,39] Reaction to anti-IgE antibody medication (omalizumab) Quick (few days) [34,41,42] Ratio of basophils in leukocytes Decrease [31,[33][34][35] Activation marker (CD203c, CD69 and CD63) No change or increase [33,38,39] Migration to dermis Increase [36,37] Non-or low-responder Tend to increase [31,34] Reaction to C5a and fMLP No change or increase [31,43]…”