Correlation Between Palmoplantar Pustulosis And Interleukin-36 Expression

OBJECTIVE: By detecting the expression level of Interleukin-36(IL-36)in peripheral blood and skin lesions of PPP(Palmoplantar Pustulosis)patients,to explore whether it is involved in the pathogenesis of PPP,and to evaluate the correlation between IL-36 and disease severity,so as to preliminarily explore the pathogenesis of IL-36 and PPP.METHOD: Fifty PPP patients were selected as the case group and twenty-five healthy controls.All PPP patients were scored with palmoplantar pustulosis area and severity index(PPPASI)and dermatology quality of life index(DLQI).The peripheral blood of patients and control group was collected for IL-36α、IL-36β and IL-36γ detection by ELISA.To study the difference of their expression level in the serum of PPP patients and normal people,and correlation analysis was used to study the correlation between serum IL-36 expression level and PPPASI score and DLQI score.Ten cases of PPP skin lesions were chosen as the case group,and three cases of normal palmoplantar skin tissue specimens were used as the reference objects.Immunohistochemical staining was used to find out the expression level of IL-36α、IL-36β and IL-36γ in skin tissues of PPP patients and normal subjects,the images were observed and photographed under the microscope.The images were analyzed by Image J software,and the average optical density was measured to reflect the expression level of the target protein,and then analyze the difference of IL-36 expression between the two groups.RESULTS: Compared with the healthy control group,there was no significant difference in IL-36α 、 IL-36β in serum of PPP patients(P>0.05),but the expression level of IL-36γincreased significantly(P<0.01).There was no significant difference in the expression of IL-36α and IL-36β between PPP patients and healthy controls(P>0.05),the expression of IL-36γ in PPP patient was significantly greater than that of another group,and the difference was statistically significant(P<0.05),IL-36γ in the lesions of PPP patients was distributed in the cytoplasm of spinous cell layer,while in the healthy control group,it was only distributed in a small number in the spinous layer.The mean PPPASI score of 50 PPP patients was9.84±3.23 and the mean DLQI score was 13.1±3.87.The expression level of serum IL-36γ in PPP patients was significantly positively correlated with PPPASI score and DLQI score(P<0.01).CONCLUSIONS:(1)The expression level of IL-36γ in serum of PPP patients increased significantly,indicating that IL-36γ is involved in the pathogenesis of PPP.(2)The expression level of IL-36γ in skin lesions of PPP patients increased significantly,it can be considered that the activation of IL-36γ is directly involved in the pathogenesis of PPP,while inhibiting IL-36γ can bring new ideas to the biological targeted therapy of PPP.(3)The results of disease severity assessment of PPP patients showed that PPP has a significant impact on their quality of life.(4)The serum IL-36γ expression level in PPP patients is positively correlated with the disease severity score,including pppasi score and DLQI score,and its serum expression level may be used as a laboratory index to judge the disease severity.