The Role And Mechanism Of Allergy Sensitization And Serum Autoreactivity In The Pathogenesis Of Chronic Spontaneous Urticaria

Background:The clinical manifestation of chronic spontaneous urtiacria(CSU)is the spontaneous appearance of wheals,angioedema or both for > 6 weeks due to known or unknown causes.CSU is a common skin diease in clinic,its etiology is unknown and the pathogenesis is complex.The pruritus of CSU is often marked and repeated for a long time,the course of the disease is often long and unpredictable.In addition,some patients were resistant to conventional antihistamine therapy.These all seriously affect the quality of life of patients.There are different clinical subtypes of chronic urticaria,usually divided into spontaneous and induced ones.CSU is the most common clinical type of chronic urticaria and It is often present in conjunction with inducible urticaria.It is often difficult to find the cause of CSU,so it is difficult to treat for the cause,currently Only symptomatic treatment is available,and the existing treatment methods and techniques can not effectively intervene in the natural course of the disease.So far,the specific pathogenesis of chronic spontaneous urticaria is not completely clear.Skin mast cells are considered to be the main effector cells in the occurrence of urticaria,and their activation and degranulation are the core of the pathogenesis of urticaria.The mechanism of mast cell activation in CSU is very complex.Both immune and non-immune mechanisms are involved.The pathogenesis varies greatly among different individual patients.Basophils are white blood cells that account for no more than 0.5% in human peripheral blood.They have biological characteristics very similar to mast cells and can be activated by the same mechanism and release the same media through degranulation.Previous studies have found that the number of basophils in chronic spontaneous urticaria is reduced,and it is closely related to the activity of the disease,suggesting that it is also involved in the development of chronic spontaneous urticaria.CD63 is a specific and reliable activation marker on the surface of basophilic cell membrane.The actual activation status of basophils in chronic spontaneous urticaria and its specific role in the pathogenesis of the disease are unknown.Mast cells and basophils are effector cells of chronic spontaneous urticarial.They have complex activation mechanisms.Current studies suggest that classical type I allergy mechanism,autoimmune mechanism,infection and nerve activation factors are involved.In addition,recent studies have also focused on immune imbalance and inflammatory factor environment that also directly affect the activation of effector cells in chronic spontaneous urticaria.The expression and function of more and more inflammatory cells have been proved to be abnormal in chronic spontaneous urticaria.These results confirm that chronic spontaneous urticaria belongs to the category of systemic inflammatory diseases.Systemic inflammatory response and immune imbalance in patients affect the occurrence and development of disease,as well as the effect and prognosis of treatment.The role of autoimmunity in the pathogenesis of chronic spontaneous urticaria has been widely concerned.Autoimmune phenomena of chronic spontaneous urticaria are usually divided into two types: Type ? is an autoallergy response that IgE induced by autoallergen,Type II is an autoimmune response that IgG autoantibodies produced by its own components,specifically IgE receptors or IgE.Autologous serum skin test(ASST)is usually used to detect the presence of autologous serum reactivity in some patients with chronic spontaneous urticaria.Already has a large number of studies have confirmed that the symptoms of disease activity,antihistamine treatment response,the natural course of the disease and quality of life score of CSU patients with serum autoreactivity(ASST positive)are significantly different from CSU patients without serum autoreactivity(ASST negative).Some studies have demonstrated that the treating ASST positive CSU patients with autogenous whole blood or serum injection can achieve a very significant effect.However,some studies have found that there is no significant difference between the clinical manifestations of these two types of CSU and the effect of autologous serum therapy is not significant too,the reason is not very clear now.Autologous serum reaction is a common phenomenon in chronic spontaneous urticaria,but its role in the pathogenesis is not universally recognized,and the specific mechanism still needs to be further studied.The role of type ?allergy(or allergy-mediated anaphylaxis)in chronic spontaneous urticaria is much debated.Allergen sensitization is usually screened and confirmed by the skin prick test(SPT).In fact,chronic spontaneous urticaria is associated with significantly higher rates of atopic disease in both children and adults than in the general population,and the proportion of positive allergens detected by SPT in CSU was much higher than that of normal population.However,there is no evidence that allergens are directly involved in the pathogenesis of chronic spontaneous urticaria from the history to the clinical manifestations.Therefore,the role and mechanism of allergen sensitization in the pathogenesis of chronic spontaneous urticaria are poorly understood.The previous researches have confirm that symptoms of disease activity,antihistamine treatment response and quality of life score in CSU patients with allergen sensitivity(SPT positive)is significantly different with CSU patients without allergen sensitivity(SPT negative),prompt that the allergen sensitivity also have the effect that cannot be ignored in the pathogenesis of CSU.Therefore,Song et al.proposed to divide CSU into four subtypes based on patients' different responses to ASST and SPT,they are ASST+SPT+,ASST+SPT-,ASST-SPT+,ASST-SPT-.The clinical characteristics of each subtype were different.To further evaluate the role and mechanism of allergic sensitization and serum autoreactivity in CSU,our study detected the expression level of basophil CD63 in patients' peripheral blood,and basophils were stimulated by serum in vitro to further study the characteristics of serum and basophil of CSU patients.Protein microarray was used to detect the expression pattern of Th1/Th2/Th17/Th22 related cytokines in patients' plasma.The role of serum autoreactivity and allergen sensitivity in the pathogenesis of CSU was systematically analyzed basing on these results.What's more,to verify the scientificity of classification of CSU based on different response of ASST and SPT.Part ?Correlation and mechanism of CD63 expression on basopihil in peripheral blood of chronic spontaneous urticaria with allergic sensitization and serum autoreactivityObjective:To investigate whether the level of basophil CD63 expression is correlated with allergen sensitization,serum autoreactivity and basophil reactivity in patients with CSU,and explore possible mechanisms.Methods:Seum and basophil-enriched leucocytes were separated from the blood of 64 patients with chronic urticaria(54 CSU patients and 10 symptomatic dermographism patients),18 healthy control subjects and seven atopic donors without urticarial.All patients with CSU were tested for ASST and SPT.Flow cytometry was then used to detect CD63 expression on the cell membrane of basophils from all samples.Analysis was also performed on basophils incubated with sera from CSU patients with positive or negative autologous serum skin test(ASST).Results:1.The expression level of CD63 in peripheral blood of CSU was significantly higher than that of symptomatic dermographism patients and healthy control.2.The expression level of peripheral blood basophil CD63 in SPT-positive CSU patients was significantly higher than that in SPT-negative CSU patients,and the former was also significantly higher than that in the atopic control group.3.The expression level of CD63 in peripheral basophils of CSU with positive ASST and/or SPT was significantly higher than that of patients with both ASST and SPT negative.4.After stimulated the basophils from patients with CSU and ASST positive patients the ASST with ASST positive serum respectively,the expression level of basophil CD63 was significantly higher than that with ASST negative serum.However,this stimulation difference did not exist in the basophils from normal people and patients with ASST negative reaction.Conclusion:The increased CD63 expression in basophils from CSU patients was confirmed,and it icorrelate with allergen sensitization,autoreactivity of serum and basophil reactivity.Our results suggest that CD63 may contribute new insight into the pathogenesis of CSU.Part ? Correlation and mechanism exploration of the expression profile of Th1/Th2/Th17/Th22 related cytokines in plasma with allergic sensitization and serum autoreactivityObjective:To explore the relationship of the expression patterns of plasma T-helper cell(Th)1-,Th2-,Th17-and Th22-related cytokines with the serum autoreactivity and the allergen sensitivity in CSU,And further explore the relevant mechanisms.Methods:Twenty related cytokines were measured and analysed in 60 patients with CSU,15 patients with acute urti-caria,10 patients with atopic dermatitis(AD)and 15 healthy persons,respectively.Demographic and clinical data were recorded in detail,and urticaria activity score(UAS7)of patients with CSU were evaluated.Autologous serum skin testing(ASST)and skin prick testing(SPT)were performed to detect autoreactivity and allergy sensitivity,respectively.The expression patterns of cytokines between different groups were systematically analyzed and compared based on the detection results.The protein–protein interaction of cytokines and the molecular pathways were analysed by Search Tool for the Retrieval of Interacting Genes/Proteins(STRING)and Kyoto Encyclopedia of Genes and Genomes(KEGG database),respectively.Results:1.The expression levels of Th1-,Th2-and Th17-related cytokines in the plasma of patients with CSU were significantly increased and correlated with the severity of the disease.The expression levels of Th2-related cytokines in plasma of patients with acute urticaria were significantly increased,and the expressions of IL-6,IL-10 and IL-13 in acute urticaria were significantly higher than those in CSU.2.In the ASST-positive patients with CSU,the expression levels of 12 cytokines in peripheral blood were significantly increased,while in the ASST-negative patients,the expression levels of only 5 cytokines were significantly increased.GM-CSF(P = 0.0011),IL-10(P = 0.026)and IL-17(P = 0.004)were significantly higher expressed in ASST positive patients than in ASST negative patients.3.In SPT-positive patients with CSU,the expression level of 13 cytokines in peripheral blood was significantly increased,while in SPT-negative patients,the expression level of only 4 cytokines was significantly increased.IFN?(P=0.0035),IL-2(P=0.04),IL-12p70(P=0.0070),and IL-21(P=0.00026)were significantly higher expressed in SPT-positive patients than in SPT-negative patients.4.IFN?,IL-2 and IL-21 were significantly varied expressed in the four subtypes of ASST+SPT+,ASST+SPT-,ASST-SPT+,and ASST-SPT-.5.Database analysis showed that IFN,IL-2 and IL-21 had close protein interactions and synergistically up-regulated the expression of STAT1 and SHC1 proteins,all of which were closely related to the JAK-STAT signaling pathway.Conclusion:This study indicates acute urticaria elicits a more prominent Th2 immune response than CSU.There was association between different expression patterns of plasma Th1-,Th2-,Th17-and Th22-related cytokines and serum autoreactivity or allergen sensitivity in CSU.Further studies on the JAK-STAT pathway in the pathogenesis of CSU are warranted.