Expression Of IL-36 In Sputum Supernatant Of The Patients With Chronic Obstructive Pulmonary Disease With Different Cell Types

Background:Interleukin 36(IL-36),as a novel pro-inflammatory factor belonging to the IL-1family,can promote cell proliferation and the production of inflammatory cytokines.It plays an important role in inflammatory diseases such as skin diseases,intestines diseases,kidneys diseases and joints diseases.In recent years,related studies have found that IL-36 plays an important role in pulmonary inflammatory diseases.Chronic obstructive pulmonary disease(COPD)is a heterogeneous disease characterized by chronic inflammatory lesions of the airways.According to the proportion of inflammatory cells in the induced sputum,four COPD subtypes were identified based on the infiltration of different inflammatory cells:Eosinophilic COPD(EC),neutrophilic COPD(NC),paucigranulocytic COPD(PC),and mixed cell type COPD(MC).Studies have shown that there are differences in the clinical characteristics,inflammatory biomarkers and the effect on standard treatment for different COPD phynotypes.This study focuses on the expression of IL-36 in sputum supernatants of patients with different cell types of COPD,it reveals that IL-36 is involved in the regulation of COPD inflammatory mechanisms and thus provided a theoretical basis for individualized treatment of patients with COPD.Objective:The aim of this study was to investigate the expression of IL-36 in induced sputum of patients with different cell types of COPD,and to reveal the regulation of IL-36 in COPD airway inflammation,and Whether IL-36 is involved in the inflammatory mechanism of different inflammatory subtypes of COPD.Thus it may contribute to the precise treatment of patients with COPD.Methods:1.Patients with stable COPD who were admitted to our hospital from May 2017 to September 2018 were randomly enrolled.At the same time,we recruited healthy subjects as a control group.All patients with COPD meet the COPD diagnosticcriteria established in the 2017 GOLD guidelines.And they meet the exclusion criteria for this experiment.According to the new classification criteria for COPD,four COPD subtypes were identified based on the infiltration of different inflammatory cells.We Collected the basic information about patients with COPD and healthy subjects,and conducted blood tests and lung function tests.Simultaneously,the induced sputum of all subjects was collected and the supernatant was isolated.2.The expression of IL-36,IL-36?,IL-36?,IL-36? in sputum supernatant was detected by multi-factor detection technique,at the same time,detected the expression of related inflammatory mediators,including interleukin-1?(IL-1?),interleukin-6(IL-6),interleukin-8(IL-8),interleukin 10(IL-10),interleukin 12(IL-12p70),interferon gamma(IFN-?),monocyte chemoattractant protein 1(MCP-1),tumor necrosis factor(TNF-?)and etc.Then,The clinical data,lung function and expression of inflammatory mediators were compared between COPD group and healthy control group,different inflammation subtypes of COPD groups.Results:1.General data comparison of the study subjects: a.This study collected a total of seventy-three patients in the COPD test group,including forty-three males and thirty females,recruit twenty healthy controls,including twelve males and eight females.b.There was no significant difference in gender and age between the two groups(P = 0.93,0.064),while the BMI level in the COPD group was lower than that in the healthy control group(P=0.001).Comparison of smoking index between the two groups showed that the COPD group was significantly higher than the healthy controls(P=0.04).The predicted values of FEV1/FVC and FEV1% in the COPD group were significantly lower than those in the control group.c.According to the COPD inflammation classification criteria,there were five patients with mixed COPD,nine patients with neutrophilic COPD,twenty-nine patients with paucigranulocytic COPD and patients with eosinophilic COPD.d.Compared with the healthy group,the total number of inflammatory cells in the sputum of the COPD group was significantly increased(P=0.002),and mainly eosinophils and neutrophils cells.the difference was significant.The percentage of macrophages in the healthy control group was significantly higher than that in the COPD group(P=0.036).2.The expression of IL36 in sputum supernatant:a.The level of IL-36 in thesupernatant of the COPD group [612.2(532.5,779.6)pg/ml] was significantly higher than that of the healthy control group [526.0(504.4,553.5)],the difference was statistically significant(P=0.000).Among the three subtypes of IL-36,IL-36?and IL-36 ? level was significantly higher than in the healthy control group,the difference was significant.while there was no significant difference between the two groups in IL-36?(P = 0.15).b.The levels of IL-36,IL-36? and IL-36? in patients with eosinophilic COPD were lower than those in non-eosinophilic COPD.The difference was statistically significant(P=0.000,P=0.000,P=0.0078);The content of IL-36? in eosinophilic COPD was lower than that in non-eosinophilic COPD,and the difference was not statistically significant(P=0.127).3.The expression of other related inflammatory factors in the supernatant of sputum: the expression levels of IL-1?,IL-6,IL-8,MCP-1,IL-23,IL-33 and IL18 in the supernatant of patients with COPD were significantly higher than those in healthy group,there is a significant difference.The expression of IL-10 and IL-12p70 in sputum supernatant in patients with COPD were lower than those in healthy controls,and there is no significant difference.IL-1?,IL-6,IL-8,IL-18,and IFN-? are highly expressed in mixed cell type COPD and neutrophil type COPD,while IL-33 is highly expressed in eosinophilic COPD,the difference was statistically significant.4.Correlation between various inflammatory factors: IL-1?,IL-8,IL-18,IFN-?,IL-36,IL-36?,IL-36? were positively correlated with neutrophils in sputum supernatant,IL-33 was positively correlated with eosinophils in sputum supernatant.IL-1?,IL-18,IFN-?,IL-36,IL-36?,IL-36? were negatively correlated with the percentage of macrophages.IL-36 was positively correlated with IL-8,IL-18 and IFN-?.IL-36? was positively correlated with IL-18 and IFN-?,and IL-36? was positively correlated with IL-8.IL-1? has a positive correlation with IL-8,IL-8 and IL-1? and IFN-?.Conclusions:1.The inflammatory cell phenotype of patients with COPD is mainly paucigranulocytic COPD and eosinophilic COPD,with fewer mixed cell types and neutrophil types.The distribution of inflammatory cells is significantly different in different COPD subtypes,which suggestes that various inflammatory cells play different roles in the inflammatory mechanism of COPD,reflectes the heterogeneity of patients withCOPD.This phenotypic classification lays the foundation for studying the inflammation mechanism of COPD.It also provides a scientific basis for precision treatment.2.As a novel pro-inflammatory factor,IL-36 promotes Th1-mediated inflammatory responses and is involved in the inflammatory subtype mechanism of COPD.