Serum Levels Of IL-9, IFN-γ And IL-17 In Patients Of Psoriasis Vulgaris And Its Correlation With PASI Score

Background: Psoriasis is a common recurrent inflammatory skin disease. It is still not chear about the pathogenesis of psoriasis. Recent studies indicated thatimmunedisorder mediated by T cells plays an important role in the occurrence and development of psoriasis. T helper 1(Th1), Th2, Th17, Th22 and regulating T cell(Treg) were widely studied in psoriasis. In addition, the peripheral blood of patients with psoriasis exist imbalance between T cell subsets, such as Th1 and Th2, Th17 and Treg. It was found that IL-9 secreted by Th9 cells also has a certain relationship with the occurrence of psoriasis recently. IL-9 shows pleiotropic effects in the immune system. IL-9 can recruit neutrophils to participate in acute inflammatory disease, and promote inflammation. Also, IL-9 could act on B cells directly, and regulate the synthesis of a variety of immunoglobulin(Ig). And IL-9 has immune regulation function. Studies found that there is a correlation between IL-9 and IFN-γ and IL-17. IL-9 and IL-17 promote the occurrence and development of disease through interaction. The interaction also exist between IL-9 and IFN-γ. However, there had no been studies showing the relationship between IL-9 and IFN-γ and IL-17 in psoriasis. Our study compared serum levels of IL-9, IFN-γ and IL-17 in patients of psoriasis vulgaris before and after treatment. To investigate its correlation with PASI score. And to discuss relationship between IL-9, IFN-γ and IL-17.We are going to discover the expression of IL-9 in psoriasis vulgaris lesion specimens and normal skin specimens, to explain its mechanism of action in the pathogenesis of psoriasis.Objective: To investigate the expression of IL-9, IFN-γ and IL-17 in the serum of patients with psoriasis vulgaris and its relationship with psoriasis area and severive index. To observe the relationships between IL-9,IFN-γ and IL-17. To compare the levels of IL-9 in the psoriasis vulgaris with that in the normal skin.Method: Part One: The expression of IL-9, IFN-γ and IL-17 in the serum of the patients group and the control group was measured by enzyme-linked immunosorbent assay(ELISA). The diversification of PASI score in patients and the expression of IL-9, IFN-γ and IL-17 in the serum of the patients was observed. The relationship between IL-9 and IFN-γ and IL-17 was analyzed.Part Two: IL-9 expression was studied by immunohistochemistry in a group of 20 cases of psoriasis vulgaris along with a control group of 15 cases.Result: Part One: 1.The expression of IL-9, IFN-γ and IL-17 in the serum of the psoriatic vulgaris patients have significant statistical difference from the expression of the control(P<0.05). 2. The levels of serum IL-9, IFN-γ and IL-17 were significantly decreased after treatment in patients with psoriasis vulgaris(P<0.05).3. The result is that the expression of IL-9, IFN-γ and IL-17 in the serum of the psoriatic vulgaris patients have significant corrrelationship with PASI score(r1=0.306,P<0.05;r2=0.453,P<0.05;r3=0.316,P<0.05).4. There is no significant difference between IL-9 and IFN-γ and IL-17.Part Two: The immunostaining signals of IL-9 in psoriatic lesions were significantly higher than that in the normal samples, the difference is significant.Conclusion: 1. The serum levels of IL-9, IFN-γ and IL-17 in vulgaris psoriasis patients are higher than the control group, and these cytokines decreased significantly after treatment. The expression of IL-9, IFN-γ and IL-17 in the serum of psoriatic vulgaris patients have positive correlation with PASI score. We can speculate that the expression levels of serum IL-9, IFN-γ and IL-17 are more representative of the severity of the disease. Maybe it can be used as an indicator to judge the severity and treatment efficacy.2. In psoriatic lesion the immunostaining signals of IL-9 is significantly higher than that in the normal samples, inhibiting their expressions may be valid manipulation for treatment of psoriasis disease.