Activated steady status and distinctive FcεRI-mediated responsiveness in
basophils of atopic dermatitis
Abstract
BACKGROUND: Although basophils are considered to play an important role
for maintenance of type 2 inflammation in atopic dermatitis (AD),
studies on basophils in AD patients are limited. Some studies have
reported the activation status, including CD203c and CD63, of peripheral
blood basophils in AD patients. OBJECTIVE: To examine the features of
circulating basophils in AD patients by assessing and comparing cell
surface marker expressions, total serum IgE, and basophil responsiveness
to stimulation between AD patients and healthy controls (HCs). In
addition, to examine the correlations among AD severity, laboratory
factors, and features of basophils. METHODS: Blood samples from 38 AD
patients and 21 HCs were analyzed. Basophil response markers CD203c and
CD63, and expression of surface-bound IgE and FcεRI on basophils were
measured. CD203c and CD63 expressions induced by stimulation with
anti-IgE and anti-FcεRI antibodies were measured. Clinical/laboratory
factors including total serum IgE were examined for correlations with
these basophil parameters. RESULTS: Basophils in AD patients were
activated spontaneously without stimulation and exhibited low
responsiveness to anti-IgE antibody stimulation. Responsiveness to
anti-FcεRI stimulation was higher than anti-IgE stimulation, contrary to
HCs. FcεRI expression on basophils was higher in AD patients than in
HCs, although surface-bound IgE on basophils was equivalent. Total serum
IgE had negative correlations with surface-bound IgE and CD63
responsiveness to anti-IgE stimulation. CONCLUSIONS: Our findings
illustrate the characteristic basophil status in AD. Despite high serum
IgE and high basophil FcεRI expression, surface-bound IgE on basophils
remained relatively low and basophils were spontaneously activated under
steady-state conditions.