Expression Of TSLP In Patients With Chronic Actinic Dermatitis And Its Clinical Significance

Objective(s):By examining the expression of thymic stromal lymphopoietin(TSLP),interleukin-25(IL-25),and interleukin-4(IL-4)in the peripheral blood and skin lesions of Chronic Actinic Dermatitis(CAD)patients,and analyzing the correlation between the serum expression level of TSLP and the Clinical Severity Score of Chronic Actinic Dermatitis(CSS-CAD),as well as the expression levels of IL-25 and IL-4,peripheral blood eosinophil(EOS)count,and serum total Ig E level.This study provides preliminary clarification on the possible role of TSLP in the pathogenesis of CAD.Methods:1.According to the CAD diagnostic criteria proposed by Norris PG et al.,52 CAD patients were selected,43 males and 9 females,aged 24-85 years old,with an average age of 57.48±13.70 years,to evaluate CSS-CAD.The patients were divided into 10 mild cases,27 moderate cases,and 15 severe cases.Twenty healthy physical examination subjects(13 males and 7 females,aged 37-75 years old,average age58.55±14.08 years)were used as the control group.5ml of peripheral venous blood was collected from each CAD patient and healthy controls.The serum concentrations of TSLP,IL-25,and IL-4 were detected using sandwich enzyme-linked immunosorbent assay(ELISA).Peripheral blood EOS count and total serum Ig E level were done by the hospital laboratory department respectively(peripheral blood EOS count by flow cytometric technique and total Ig E determination by scattering turbidimetric method).There was no significant difference in general clinical data such as age and gender between the case group and the control group.2.Ten paraffin-embedded skin biopsy specimens were selected from CAD patients,8 males and 2 female,with an average age of 65.50±9.51 years.Five Atopic Dermatitis(AD)patients were used as positive controls,7 males and 3 females,with an average age of 56.40±15.06 years.Ten normal skin tissues were used as normal controls,8 males and 2 females,with an average age of 51.70 ± 13.37 years.Immunohistochemistry was used to detect the expression of TSLP、IL-25 and IL-4 in CAD lesion,AD lesion,and normal skin tissues,and there was no statistically significant difference in age and gender among the three groups.Results:1.Serum TSLP,IL-25,IL-4,total Ig E levels and peripheral blood EOS counts were significantly higher in patients in the CAD group than in healthy controls(P<0.05).Serum TSLP levels increased progressively in the mild,moderate and severe groups of CAD patients,with statistically significant differences between the groups(P<0.05).Serum IL-25 levels were statistically significant(P<0.05)in the mild group versus the severe group,and the moderate group versus the severe group,while the differences were not statistically significant(P>0.05)in the mild and moderate groups.Serum IL-4 levels were statistically significant(P<0.05)in the mild group versus the severe group and the moderate group versus the severe group,while the difference was not statistically significant(P>0.05)in the mild and moderate groups.The difference in peripheral blood EOS count was statistically significant(P<0.05)in the mild group versus the severe group,while the difference was not statistically significant(P>0.05)in the mild group versus the moderate group and the moderate group versus the severe group.The differences in serum total Ig E levels were not statistically significant(P>0.05)between the mild and moderate,mild and severe,and moderate and severe groups.2.The differences in serum TSLP,IL-25,IL-4,total Ig E levels and peripheral blood EOS counts were not statistically significant between CAD patients of different genders(P>0.05).3.Serum TSLP levels were positively correlated with IL-25,IL-4 levels and CSS-CAD(P<0.05)and not significantly correlated with peripheral blood EOS count and serum total Ig E levels(r=0.1228,r=0.049)(P>0.05);serum IL-25 expression levels were positively correlated with IL-4,total Ig E levels,peripheral blood Serum IL-25 expression level was positively correlated with IL-4,total Ig E level,peripheral blood EOS count and CSS-CAD score(P<0.05);serum IL-4 expression level was positively correlated with peripheral blood EOS count and CSS-CAD score(P<0.05),but not with total Ig E level(r=0.142,r=-0.050)(P>0.05).4.TSLP and IL-4 were highly expressed in the basal cells and the overlying keratinocytes of the epidermis in the lesional tissues of both CAD and AD groups,while weakly expressed in the basal cells of the healthy control group.IL-25 was weakly expressed in the keratinocytes of the epidermis in the lesional tissues of both CAD and AD groups,but not expressed in the healthy control group.The positive expression rates of TSLP,IL-25 and IL-4 in CAD and AD groups were significantly different from those in the healthy control group(P<0.05).However,there was no significant difference in the positive expression rates of TSLP,IL-25 and IL-4between the CAD and AD groups(P>0.05).Conclusion(s):1.TSLP expression is elevated in serum and skin lesions and correlates with disease severity,and TSLP can be used as a reference indicator to detect disease activity.2.Serum IL-25 and IL-4 levels were higher in the CAD group than in healthy controls,both of which may be involved in the pathogenesis of CAD,and the pathogenesis of CAD may be related to the Th2 type of inflammatory response.