Increased blood group 2 innate lymphoid cells are involved in blood
eosinophilia and itching in Kimura disease
Abstract
Background: Kimura disease (KD) is a rare, chronic inflammatory
disorder characterized by blood eosinophilia, general itching, and
subcutaneous head and neck mass lesions; however, the etiology of this
disease is unknown. We hypothesized that group 2 innate lymphoid cells
(ILC2s) in peripheral blood may play an essential role in the
pathogenesis of KD. Methods: The prevalence of blood ILC2s and
their ability to produce interleukin (IL) -4, IL-5, IL-13, and IL-31 in
patients with KD were compared with those in control subjects and in
patients with house dust mite (HDM) -induced allergic rhinitis (AR).
Changes in blood ILC2 prevalence, blood eosinophilia, and clinical
symptoms after surgery and steroid therapy were evaluated.
Results: Blood ILC2 prevalence in patients with KD were eight
times and six times higher than those in control subjects and in
patients with AR, respectively. There was a strong positive correlation
between ILC2 prevalence and blood eosinophilia. Patients with KD showed
increased serum IL-13 and decreased IL-31 levels. KD patient-derived
blood ILC2s produced large amounts of IL-5 and IL-13 in response to
prostaglandin (PG) D 2 and leukotriene (LT) D
4, compared to ILC2s derived from control subjects and
patients with AR. Surgery and systemic steroid therapy ameliorated
general itching with a concomitant decrease in blood ILC2s and blood
eosinophilia. Upon disease recurrence, blood ILC2 prevalence and blood
eosinophilia increased concurrently with general itching.
Conclusion: Increased blood ILC2s may be involved in blood
eosinophilia and general itching through the production of IL-5 and
IL-13 in patients with KD.