Proportion And Significance Of Myeloid-derived Suppressor Cells In Peripheral Blood Of Patients With MOG-IgG Associated Disorders

Background and Objective:The aim of this study is to compare the percentage of myeloid-derived suppressor cells(MDSCs)and different subsets in peripheral blood mononuclear cells(PBMC)of MOG-Ig G associated disorders(MOGAD)patients in the acute phase and after glucocorticoid treatment,and analyze their correlation with the severity of MOGAD.We hope to explore the role of MDSCs in the pathogenesis of MOGAD,provide new ideas for revealing the pathogenesis of MOGAD and find therapeutic targets.Methods:According to the inclusion criteria,we selected 16 patients with MOGAD in acute phase from January 2022 to December 2022.They were hospitalized in the Department of Neurology,the First Hospital of Jilin University.10 patients were treated with methylprednisolone sodium succinate and blood samples were successfully collected.At the same time,we selected 15 healthy controls(HC),whose age and gender were matched with the patients in the acute stage.All patients were diagnosed by two neurological physicians according to the diagnostic criteria of MOGAD recommended by the Chinese expert group in 2020.We collected the clinical data and performed the EDSS score of the enrolled patients.Using flow cytometry detected the percentage of MDSCs in PBMC and different subsets of MDSCs in the peripheral blood of healthy people and MOGAD patients in the acute phase and after treatment.Flow cytometry was used to detect the secretion of arginase 1(Arg-1)by MDSCs in the peripheral blood of MOGAD patients.The correlation of MDSCs and their subsets with EDSS and annual relapse rate(ARR)in patients with acute MOGAD was analyzed.Results:(1)Compared with healthy people,the percentage of MDSCs in the peripheral blood of MOGAD patients was significantly increased.There was no significant difference in the percentages of G-MDSCs and M-MDSCs subsets in the total MDSCs.(2)Compared with the acute phase,the percentage of MDSCs in peripheral blood was significantly increased after methylprednisolone sodium succinate treatment.There was no significant difference in the percentage of G-MDSCs in the total MDSCs between the two groups,while the percentage of M-MDSCs increased after treatment.(3)The expression of Arg-1 in MDSCs in the acute phase was slightly higher than that in HC,but there was no statistical significance.There was no significant change in the expression of Arg-1 in MDSCs in the peripheral circulation of MOGAD patients after treatment.(4)Statistical analysis showed that HLA-DR~-CD11b~+MDSCs and their two subsets were not correlated with EDSS score and ARR.Conclusion:(1)Compared with healthy people,MDSCs in the peripheral blood of MOGAD patients were increased in the acute phase,and the percentage of MDSCs in PBMC was increased,suggesting that MDSCs may regulate the immune response in MOGAD patients.(2)After methylprednisolone sodium succinate treatment,the number of MDSCs in patients increased significantly,suggesting that methylprednisolone may induce the differentiation and expansion of MDSCs with immunosuppressive function,thereby alleviating the disease.(3)The percentage of G-MDSCs in the peripheral blood of acute-phase patients increased slightly,while the percentage of M-MDSCs decreased,and the percentage of M-MDSCs increased after treatment,suggesting that M-MDSCs could enhance the immunosuppressive effect in MOGAD.(4)There was no significant difference in Arg-1 expression between the acute phase and the healthy control group,and Arg-1 did not increase significantly after treatment.This suggests that Arg-1 may not be the dominant immunosuppressive factor in M-MDSCs in MOGAD.