The Role Of Th9 Cells And IL-9 In Primary Immune Thrombocytopenia

Objective:To explore the expression of Th9 cells and its cytokine interleukin(IL)-9 in primary immune thrombocytopenia(ITP)and its relationship with B cell activation.Methods:Peripheral blood of 30 newly treated ITP patients and 20 healthy controls were collected,and the number of Th9 cells and B cells was detected by flow cytometry(FCM);PU.1 and IL-9 mRNA expression levels was detected by real-time fluorescence quantitative PCR(qRT-PCR).Serum IL-9 and sBAFF cytokine expression levels were measured by enzyme-linked immunosorbent assay(ELISA).Results:Compared with 20 healthy controls,the number of Th9 cells,B cells,PU.1 mRNA,IL-9 mRNA,serum sBAFF,and serum IL-9 expression were increased in 30 newly treated ITP patients(P<0.05).Compared with the newly-treated ITP group,the expression of Th9 cells,PU.1mRNA,IL-9mRNA,serum sBAFF,and serum IL-9 in ITP patients after treatment decreased in 20 patients(P <0.05);the expression of B cell ratio increased(P<0.001).Correlation analysis: There is a positive correlation between PU.1 mRNA expression and IL-9 mRNA expression in newly treated ITP patients;The number of Th9 cells,and the serum IL-9 concentration,serum sBAFF concentration were positively correlated with B cell number,platelet count and serum IL-9 concentration,sBAFF concentration was negatively correlated.There was no correlation between Th9 cell number,PU.1 mRNA expression level,serum IL-9 and serum sBAFF.Conclusion : In primary immune thrombocytopenia,Th9 and its cytokine IL-9 may participate in the pathogenesis by promoting B cell activation.