| Urticaria (uricaria), also known as the "wheal", is common allergic skin disease. The occurrence of uricaria is about 20% of all skin disease. Urticaria belongs to immunological disorder, which is characterized as a localized edema along with the skin, mucous membrane of small vessel expansion and increasing permeability. Although urticaria can self-healing within 24 h, it will re-occur and last a few months. Clinically, urticaria is classified as acute urticaria (AU) and chronic urticaria (CU) according to the length of the disease course and its frequency. AU is often recovered in 6 weeks, while CU lasted for more than six weeks. CU has complicated pathogenesis including heredity, environment, and the immune effect. Studies have shown that CU is mainly caused by type I allergy reaction, allergens lead Fc of IgE bind to Fc receptor that on the surface of mast cells, basophils and neurtorphil, these cells degranulation, releasing histamine, arachidonic acid derivatives etc. allergy medium, which lead to smooth muscle contraction, immune cell migration, blood capillary dilation, and glands lesions. At the same time, research reveal that patients with CU often accompanied by infiltration of eosinophil, neutrophils, and CD4+T cells as well as Thl/Th2 imbalance. This may be caused by chemokines. Chemokines play an important role for the attracting immune cells and other cells migration. Chemokines will be divided into chemokine CC, CXC, C and CX3C. chemokines CC not only have the chemotaxis, but also participate in immune regulation, antiviral immunity, regulating cell metabolism, promote the release of histamine in allergic reactions. Research shows that large quantities of eosinophil, which can secrete CC chemokine, appears at the skin lesions of CU. CC can cause skin damage and itching in CU by stimulating the eosinophil secreting acidophilic granulocyte cationic protein and acidophilic granulocyte peroxidase toxic ingredients. In addition T helper cells play a crucial role on controlling immune response. Th cells, including Thl and Th2 cells, maintain a dynamic balance in the body under normal circumstances. When the disbalance occured, Th1/Th2 drift, causing Th0 shift to Thl differentiation, this is the pathogenesis of autoimmune diseases and delayed hypersensitivity. On the other hand, when ThO shift to Th2 differentiation, it often causes allergic diseases such as asthma and CU. When the body’s immune dysfunction is low, the levels of Th2 cells as well as cytokines will increase in serum IgE levels of chronic urticaria patients. At present, IgE mediated type I allergy and Th1/Th2 cells balance is considered to be the main regulatory mechanism of CU. There exists correlation between chemokines and Thl/Th2 imbalances in allergy disease. Therefore, to clarify the role of chemokines in CU have clinical significance in CU treatment.Currently, it is important to identify, remove the cause and reduce exposure induced factors associated with CU. The pathogenesis of CU was IgE mediated type I allergy, which in turn caused mast cells and basophils degranulation. In recent years, the allergen detection and atopic immune therapy is international allergy industry extensively developed a new kind of detection and treatment. Subcutaneous injection of specific immunotherapy (SCIT) is a clinical classic immune method that has been widely applied, however, it has been replaced by under the tongue specific immune therapy (sublingual immunotherapy, SLIT) for the lack of higher security. As the only for allergic diseases for treatment SLIT has been widely used in clinic due to their remarkable curative effect, high safety, easy to use. It helps patients fundamentally desensitization by repeatedly contacting the allergens at the certain dose. Allergens contacted by tongue are convenient and safe method that benefit for patients than the intravenous injection high-dose allergens. The allergens is captured by the dendritic cells of lymph nodes, interacting with CD4+T cells and regulating Thl/Th2 balance through relaeasing cytokines or chemokines. Its possible mechanism is the use of closed antibody (mainly IgG), combined with allergens and the corresponding antibody, thus blocking the IgE allergens, form the immune complex does not produce allergy. It has few side effects and long efficacy, which has widely been exploited in CU’s treatment. But the therapeutic effect of SLIT on CU and the underlying mechanism has not been fully elucidated.This study is aimed to investigate the role of CC chemokine CCL11 (acidophilus granulocyte activation chemokines, eotaxin-1), CCL17 (thymus and activation-regulated chemokine), CCL26 (eotaxin-3) and CCL27 (cutaneous T cell-attracting chemokine) in the pathogenesis of urticaria, which will provide evidence for the urticaria treatment. Moreover, we explored the clinical efficacy of specific immune therapy in patients with CU and the correlations between four kinds of chemokine expression and urticaria treatment. Our data will help for elucidating the role of specific immune treatment on CU.The first part of this study applied real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and liquid phase chips based on Luminex platform Bioplex technology to determine four chemokines CCL11, CCL17, CCL26, CCL27 mRNA expression level and protein content in the serum and peripheral blood mononuclear cells (peripheral blood mononuclear cells of PBMCs) in 27 cases of patients with acute urticaria (AU),24 cases of patients with chronic urticaria (CU), and 25 cases of healthy volunteers. Also the relationship between CCL11, CCL17, CCL26, CCL27 in PBMCs and Thl and Th2 were measured. Statistical method was applied to analyze the correlation among four chemokines, the disease course, UAS scores and Thl/Th2 cytokines levels. Our results revealed that mRNA level and protein content of three chemokines CCL11, CCL17, CCL26 in PBMCs were significantly higher in patients with CU than those of healthy subjects (P< 0.05). And this difference was more significant in PBMCs of AU patients (P< 0.05). CCL27 mRNA expression and protein content is significantly increased in AU group (P< 0.05), but decreased slightly in the patients with CU (P> 0.05). Chemokines content in PBMCs of urticaria patients changes. IL-2, and TNF alpha in AU and CU groups were significantly lower (P< 0.05), and CU group was significantly lower than AU group (P< 0.05); Th2 cytokines IL-4 expression in patients with AU and CU group were significantly increased (P< 0.05), the Th2 cytokine expression of IL-10 in patients with CU group increased significantly (P< 0.05), and higher than the AU group of patients (P< 0.05), indicating Th1/Th2 imbalance occurred in urticaria. Further analysis of secretion of Thl and Th2 cytokines in serum, found that AU CCL17 and CCL27 and Thl cytokines in patients with negative correlation; Its CCL11, CCL17 and CCL27 was positively correlation with Th2 cytokines. Negative correlation exists between CU CCL17, CCL26 and CCL27 and Thl cytokines; while positive correlation were found between CCL17 and CCCL27 and Th2 cytokines; CCL11 positivly related with IL-4 (P< 0.05); Its negative correlation CCL26 and Th2 cytokines, further evidence Thl, Th2 development has significant correlation with the incidence of urticaria. However, regulation and control of CU important immunoglobulin IgE levels, in patients with AU and CU group than the control group had no significant change (P> 0.05). And chemokines content in PBMCs of patients with CU and serum total IgE and peripheral eosinophil count had no significant correlation (P> 0.05). In conclusion, CU can promote ThO cell differentiate into Th2 cells, and inhibiting ThO cells to differentiate into Thl cells, damaging the body’s dynamic Th1/Th2 balance. And the levels of CCL11, CCL17, CCL26 and CCL27 not only were related with Th1/Th2 balance, but also closely related to the severity of urticarial. Therefore, they can be used as auxiliary diagnosis of AU and CU potential index and has important clinical significance for the future timely diagnosis for urticaria condition.In the study of the second part, the origin prick test method was used to perform allergen detection in CU patients and normal controls. Then we compared the differences in two groups and found dust mites is the main allergens. The patients with CU were randomly divided into two groups according to dust mites, one group was treated with SLIT method. Another group received routine antihistamine treatment as control group. To study the different efficacy of two groups, CC chemokines, and Thl/Th2 cytokines expression. Our results revealed that serum levels of CCL17, CCL26 and CCL27 were significantly higher in severe urticaria group than those in moderate group and mild group (P< 0.05), which has certain significance to the urticaria diagnosis. And after two kinds of therapy, the SSRI value in SLIT treatment group was (0.41±0.19) and (0.73±0.21) in week 16 and 24 weeks, respectively. The SSRI value in the control group was (0.31±0.15) and (0.47 ±0.18) in week 16 and 24 weeks, respectively. Statistical analysis showed that SLIT immunotherapy is significantly higher than control group (P< 0.05). Total effective rate in immune therapy group and control group were 72.2% and 33.3% respectively, and the immune treatment group is significantly higher than the control group (P< 0.05). Above all, SLIT therapy for the treatment of urticaria, effectively and with regular antihistamines treatments have synergy, urticaria occurs at the same time, it indicates a SLIT regulation mechanism is different from the treatment of antihistamines. Mechanically, SLIT can significantly reduce CCL11 SLIT, CCL17 CCL26 levels (P< 0.05), improve the level of CCL27 (P< 0.05), enhance the Thl cytokines IL-2 and TNF-2 expression levels (P< 0.05), and thereby reduce the Th2 cytokines IL-4 and IL-10 expression levels (P< 0.05). Results suggest SLIT can be adjusted by chemokines CCL11, CCL17, CCL26, CCL27 expression levels, significant correcting Thl/Th2 drift, restore the body’s dynamic Thl/Th2 balance. Regular treatment has no obvious improvement and found to be inferior to SLIT. These results further demonstrated that chemokines CCL11, CCL17, CCL26 and CCL27 were closely associated with the incidence of CU, which can be used as potential biomarkers in urticaria diagnosis and evaluation curative effect as well as new targets for the treatment of CU.To sum up, this study analyzed the correlation between the cytokines, Thl/2 balance and chemokines in the treatment process of CU. The results showed that chemokines CCL11, CCL17, CCL26 and CCL27 regulated Thl/Th2 balance. The occureence of CU promoted ThO cell differentiation into Th2, and inhibiting the Th0 cells to differentiate into Thl cells, thus increase Th2 cytokines, reduce Th1 cytokines, damaging the body’s dynamic Th1/Th2 balance, a step significantly enlarge the symptoms of urticaria. At the same time, CCL17, CCL26 and CCL27 level is closely related to the severity of urticaria. SLIT CU with obvious therapeutic effect, the significant effect may be related to patients’ CCL11, CCL17, CCL26, CCL27 level. All of these results revealed that chemokines CCL11, CCL17, CCL26 and CCL27 may as a potential biomarkers for urticaria diagnosis, which involved in the pathogenesis of urticaria. These chemokines not only with chronic urticaria is closely related to the degree of disease progression, and has a great application prospect in clinical application. These findings have laid a solid foundation for the pathogenesis of CU. Other SLIT in the identified allergen CU both from the perspective of clinical or laboratory shows the effectiveness of treatment. It can be aimed at pathogeny cure, improve the clinical symptoms, reduce relapse, frequently, to attack symptoms stubborn and recommended therapy.Important technical highlight of this study is the use of liquid phase factor platform, to detect the contents of serum chemokines. Compared with the traditional ELISA, it is more accurate, efficient and can save valuable clinical samples, obtained multiple factor test results in the same experiment, which make the data more accurate. The limitation of this study is our small sample size, especially only 6 cases of patients in the conventional treatment as control. Therefore, further clinical application still needs more samples to system analysis and evaluation. There are many chemokines involved in chronic urticaria and the complex regulatory mechanism. The future study will aim to reveal more chronic urticaria chemokine expression, which will be greater significance for uncovering the regulation mechanism. |
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