Pathogenesis of Chronic Urticaria: An Overview

Table 3

Basophil phenotypes: profile in chronic urticaria [31–33].

Feature	Chronic urticarial (autoimmune/nonautoimmune)
	CIU-R	CIU-NR
(1) Anti-IgE stimulation/cross-linking: HR in active disease	>10 percent of cellular content	<10 percent of cellular content
(2) Regulatory proteins	Paradigm shift	Paradigm shift
(a) Kinase	HR not determined by kinase level	HR not determined by kinase level
	Normal Syk levels	Normal Syk levels
(b) Phosphatase	Regulates HR, reduced SHIP-1 levels	Regulates HR, increased SHIP-2 levels
(3) Sensitivity to anti-IgE stimulation in remission	Heightened sensitivity	Sensitivity restored to levels as in normal healthy subjects

HR: histamine release.
CIU-R: chronic idiopathic urticaria—responders.
CIU-NR: chronic idiopathic urticaria—nonresponders.
Syk: serum tyrosine kinase.
SHIP-1: Src homology 2 (SH2) containing inositol phosphatase 1.
SHIP-2: Src homology 2 (SH2) containing inositol phosphatase 2.