Profile of chemokine and cytokine secretion and expression in chronic idiopathic urticaria

Author(s)

Juliana Cristina dos Santos

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2010-08-20

Examining board members

Maria Notomi Sato; Fernando Augusto de Almeida; Valeria Aoki

• Advisor: Maria Notomi Sato

Abstract

INTRODUCTION: Chronic urticaria is skin disorder characterized by recurrent and transitory itchy weals occurring regularly for more than 6 weeks. The aetiology is not identified in most patients being considered as idiopathic (CIU). The immunological dysregulation in CIU could be due to a disturbed cytokines and chemokines production. OBJECTIVES: To evaluate the pattern of cytokine and chemokine in CIU patients who undergone autologous serum skin test (ASST), assessing sera, mRNA expression and intracellular expression of peripheral blood mononuclear cells (PBMC) through the secretion upon induced by policlonal stimuli. METHODS: CIU patients (n=37) were selected from the Dermatological Outpatient Clinic of the Hospital das Clínicas de São Paulo (HC-FMUSP) and submitted to the ASST. The control group consisted of healthy subjects (n=33). Cytokine and chemokine levels were assessed by flow cytometer and ELISA and mRNA expression was analyzed by Real-Time PCR. RESULTS: Elevated levels of TNF-, IL-6, IL-1, IL-12p70 and IL-10 were observed in sera from CIU patients compared to healthy control group. CIU patients also showed increased IL-2 production by PBMC stimulated with phytohemagglutinin (PHA). Moreover, it was observed higher IL-17A and IL-10 levels in the ASST+ group compared to control group. The IL-10 mRNA expression was diminished in the ASST- group compared to control group. Furthermore, an increased lymphoproliferative response to Pokeweed mitogen was observed in the ASST+ patients compared to healthy subjects. Seric levels of CXCL8, CCL2, CXCL10 and CXCL9 were higher in CIU patients. Regarding the in vitro chemokines secretion, it was detected higher basal levels of CCL2 in CIU patients, which was increased by Staphylococcus aureus enterotoxin A (SEA). Stimulation with PHA increased the CXCL8 and CCL5 production by CIU mononuclear cells. The main source of CXCL8 was the CD14+ cells. CIU CD14+ cells showed decreased mean fluorescence intensity and percentage of CXCL8 expression with and without SEA stimuli. The percentage of CD14+ producing CCL2 was lower in ASST- patients compared to healthy control subjects. Furthermore, in the absence of stimuli the percentage of CCR5-expressing CD8+ T cells was higher in CIU patients, mainly due to an increased expression by the ASST+ group. CONCLUSIONS: These results indicate an immunological dysregulation in CIU, without association to ASST response, which was evidenced by the increased production of pro-inflammatory cytokines and chemokines. The data suggest a higher activation of monocytes and lymphocytes in CIU, which may contribute to its immunopathogenesis (AU)