Decreased CRTH2 Expression and Response to Allergen Re-stimulation on Innate Lymphoid Cells in Patients With Allergen-Specific Immunotherapy

PURPOSE: Group 2 innate lymphoid cells (ILC2s) have been implicated in the pathogenesis of allergic disease. However, the effect of allergen-specific immunotherapy (AIT) on ILCs remains to be clarified. The aim of this study was to evaluate the levels of ILC subsets in allergic rhinitis (AR) patients in response to house dust mite (HDM)-specific immunotherapy. METHODS: We enrolled 37 AR patients undergoing AIT (16 responders and 11 non-responders) for 2 years, 35 HDM AR patients and 28 healthy subjects. Peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry to identify ILC subsets. Stimulation of ILC2s with recombinant allergen-specific protein was used to determine ILC2's activation (CD69 expression). RESULTS: Responder AIT patients and healthy subjects had a decreased frequency of circulating ILC2s compared to non-responder AIT and AR patients. Conversely, ILC1s from responder AIT patients and healthy subjects showed increased frequency compared to non-responder AIT and AR patients. The frequency of ILC3s natural cytotoxicity receptor (NCR)+ and NCR− in responder AIT patients was significantly lower compared to AR patients and healthy subjects. The ILC1: ILC2 proportion in responder AIT patients was similar to that of healthy subjects. PBMCs from patients who were responders to AIT had a significantly lower expression of the activation marker CD69 on ILC2s in response to allergen re-stimulation compared to AR patients, but no difference compared to non-responder AIT patients and healthy subjects. CONCLUSIONS: We propose that AIT might affect ILC responses. The activation of ILC2s was reduced in AR patients treated with AIT. Our results indicate that a relative ILC1/ILC2 skewed response is a possible key to successful AIT.

Autologous serum and plasma skin test to predict 2-year outcome in chronic spontaneous urticaria

BACKGROUND: Autologous serum skin test (ASST) and autologous plasma skin test (APST) are simple methods to diagnose autoimmune chronic urticaria. However, the association data of ASST or APST with disease severity and long-term outcome are still unclear. OBJECTIVE: The results of ASST and APST might be used to predict urticaria symptom severity and long-term outcomes among chronic spontaneous urticaria (CSU) patients. METHODS: We evaluated the prevalence of reactive ASST and APST in 128 CSU patients. The patients were characterized by 4 groups: negative, ASST positive, APST positive, and both ASST and APST positive. We observed remission rate among the CSU patients during 2 years. RESULTS: Forty-four of 128 CSU patients (34%) had negative autologous skin test. The CSU patients with positive ASST, positive APST, and both positive ASST and APST were 47 (37%), 6 (5%), and 31 (24%), respectively. No significant difference was found between the groups according to urticaria severity score (USS) and dermatology life quality index (DLQI). Mean wheal diameter of ASST showed positive correlation with DLQI. Also, mean wheal diameter of APST showed positive correlation with USS and DLQI. Both the positive ASST and APST groups had a high proportion of 4-fold dose of H1-antihistamine than the positive ASST (p = 0.03) and negative groups (p = 0.0009). The rate of remission over 2 years in the negative, positive ASST, positive APST, and both positive ASST and APST groups were 81.1%, 62.3%, 60%, and 46.1%, respectively. The urticaria remission rate in patients in the negative group was significantly higher compared with both positive ASST and APST groups (odds ratio, 5.0; 95% confidence interval, 1.61–15.44; p = 0.006). CONCLUSION: ASST and APST results could predict remission rates among patients with CSU. Our results suggested investigating ASST and APST among CSU patients before starting treatment.