The Study Of The Effect Of Specific Immunotherapy On The Clinical Symptoms And The Serum Levels Of IL-13 And IFN-γ In Chronic Urticaria Patients

Objective: Chronic urticaria is a common disorder in dermatogic diseases. As all know, the main pathogenesis of chronic urticaria is immediate hypersensitivity. Recently some scholars suggest that functional disorder of T helper lymphocyte subpopulation was correlated with allergic diseases. IL-13 and IFN-γare representative Th1/Th2 type cytokines respectively. IL-13 is mainly secreted by activated Th2 lymphocytes, which plays a part in allergic reaction by regulating B lymphocytes, eosinophils, endothelial cells, monocytes and macrophages, et al. IFN-γplays an important role in immunoloregulation and it is the main cytokine which favors CD4+ T lymphocytes'shift to Th1 lymphocytes. The study in vitro suggested that IFN-γinhibited the production of Th2 lymphocytes and induction of IL-4, which induced B lymphocytes to synthesis IgE and express IgE receptor (FcγR). It was reported that IL-13 and IFN-γwere produced abnormally in many allergic diseases. Specific immunotherapy (SIT) in chronic urticaria is desensitization aimed directly at allergen, which eventually lead to clinical remission. SIT has been successfully applied to allergic diseases for more than ninety years at home and abroad. The clinical efficacy of SIT has been proved by several trials, but the mechanisms are less well understood. In this study, we treated thirty chronic urticaria patients by SIT, and then observed the effect and measured serum levels of IL-13 and IFN-γbefore and after SIT. The purpose of this study is to access the role of functional subsets of T helper lymphocytes in chronic urticaria and clarify the pathogenesis of this disease. On the other hand, we observe the influence of SIT on production of Th1/Th2 cytokine (IFN-γ, IL-13) and try to evaluate the therapeutic efficacy of SIT through clinic and serology marker and explore the mechanisms of SIT and clinical significance of assay of IFN-γand IL-13 in chronic urticaria. It will provide reliable and objective evidence to clinical therapy. Methods: The case group involved thirty typical chronic urticaria patients who were selected in out-patient clinic in the second hospital of Hebei Medical University from April, 2003 to October, 2004. All the patients gave a positive response to an allergen skin test. We excluded patients with autoimmunity diseases such as erythema lupus, pemphigus, dermatomyositis, rheumatic arthritis, et al, patients with tumor, with other severe Systemic diseases or allergic diseases. All the cases involved had not taken antihistamines for three days, astemizole for one month, or drugs that could affect immunological function for two months such as corticosteroids and immunosuppressive agent, et al. The control group involved twenty healthy people without allergic diseases, autoimmunity diseases and familyhistory. After giving positive responses to allergen skin tests, the patients of case group have been treated with SIT for three to six courses. We recorded the skin eruption, subjective symptoms before and after SIT, gave scores and calculated SSRI (symptom score reducing index). The standards of effect evaluation are as follows. Cure: SSRI ≥90%. Effective: 60%≤SSRI<90%. Little effective: 30%≤SSRI<60%. Ineffective: SSRI <30% (aggravate or no change). Four milliliters blood samples from healthy controls and patients before and after SIT were collected and separated. Serum levels of IFN-γand IL-13 were measured by ELISA according to directions in the test kit. Results: 1.The effective rate was 76.67% after three to six courses of SIT. 2. The clinical scores were signigicantly lower after SIT than before SIT. (t=17.022,P<0.01) 3. The levels of IL-13 in the serum of urticaria patients were significantly higher than that of control subjects. (t=2.798,p<0.01) After treatment, the levels of IL-13 were significantly decreased.(t=3.171,P<0.01) 4. The levels of IFN-γin the serum of urticaria patients were significantly lower than that of control subjects. (t=3.772.,P<0.01) After treatment, the levels of IFN-γwere significantly increased. (t=-7.21,P<0.01 )5. In chronic patients, there was no significant correlation between the serum levels of IL-13 and IFN-γ. (r=-0.128,P>0.05). Conclusion: 1. Specific immunotherapy is an effective and safe treatment of chronic urticaria.2.There exists disequilibrium of T helper lymphocytes in allergic urticaria.3.Correlationanalysis showed that there was no correlation between the serum levels of IL-13 and IFN-γ.4. SIT maybe play an important role by modulating the function of immune system in the beneficial effect of SIT.