Correlation Between Systemic Lupus Erythematosus Patients' Monocyte Subsets In Peripheral Blood And Disease Activity

BackgroundSystemic lupus erythematosus is a diffuse connective tissue disease mediatedby autoimmunity and characterized by immunological inflammation,mainly involving the skin and joints,and accompanied by kidney,heart and nerve multisystem damage.The presence of multiple autoantibodies and multiple system involvement represented by antinuclear antibodies are the two main clinical features of SLE.With increasing use of antimalarial drugs and immunosuppressants,the prognosis of SLE has improved significantly compared with the past.However,high disease activity during the course of the disease is still an independent risk factor for SLE mortality.Therefor,it is important to monitor the change of disease activity in time in the treatment of SLE system.At present,the cause of SLE are not clear.The abnormal activities of various immune cells are involved in the immune dysfunction of SLE.With the recent research on the Toll like receptor family?TLRs?and IFNs,it is shown that the innate immune response and its products are important pathogenic factors of SLE.Monocyte is a group of immune cells derived from marrow myeloid stem cells.It plays an important role in the non specific defense,tissue repair,and tumor surveillance of the pathogens.Monocytes also perform important immunomodulatory functions,secrete a variety of cytokines,and play a important role in the inherent immune response and in the adaptive immune response.In recent years,more and more evidences support monocyte subsets with different functions and different roles in the human immune system.CD14⁺⁺CD16^-classical monocyte subsets have been proved to be the strongest phagocytic cells in monocyte subsets by functional experiments.They are important scavenging cells and play an important role in the first line of innate immune defense in the blood system.CD14⁺⁺CD16⁺intermediate monocyte subsets have more prominent antigen-presenting ability,activate T cells,induce T cell proliferation,and have higher potential to activate inflammatory response.At the same time,CD14⁺CD16⁺⁺nonclassical monocyte subsets with function of patrol,continuous observation of vascular system,selective phagocytosis of dead and diseased endothelial cells plays a protective role to some extent.Although more and more studies have shown that monocytes play an important role in many autoimmune diseases such as SLE,RA,AS and Ssc,there is still a debate on the distribution of mononuclear cells in peripheral blood of patients with SLE.Objective1.This study aims to explore the distribution of monocyte subsets in peripheral blood of SLE patients and healthy people,and to reveal their role in the pathogenesis of SLE.2.To explore the relationship between the distribution of monocyte subsets in peripheral blood of patients with SLE and the clinical parameters of SLE,and to explore whether the distribution of monocyte subsets is related to the activity of SLE.Materials and MethodCollected fresh peripheral anticoagulant blood from 74 patients with SLE?33cases of remission group and 41 cases of disease activity group?and 36 cases of healthy people?healthy control group?according to SLEDAI score.After PBMC was extracted,the percentage of different monocyte subsets and its subsets were detected by flow cytometry.The results of laboratory examination form SLE patients in the second affiliated Hospital of Guangzhou Medical University.The correlation analysis of monocyte and its subsets in peripheral blood and clinical activity of patients with SLE including,ESR,CRP,C3,C4,ANA and anti ds-DNA were carried out.ResultsThere was no difference in the proportion of monocytes in peripheral blood between SLE patients and healthy people.The percentage of CD14⁺⁺CD16^-classical monocyte subsets in peripheral blood decreased significantly.The proportion of CD14⁺CD16⁺⁺nonclassical monocyte subsets increased significantly,but neither of them was related to the disease activity of SLE.The percentage of CD14⁺⁺CD16⁺intermediate monocyte subsets in peripheral blood increased with the aggravation of SLE activity?disease activity group>remission group>healthy control group?.At the same the proportion of CD14⁺⁺CD16⁺intermediate monocyte subsets in peripheral blood of SLE patients was positively correlated with the index of disease activity?ESR,CRP,C3,C4,ANA and anti ds-DNA antibody?.Conclusions1.The proportion of monocyte subsets in peripheral blood of SLE patients is significantly different from that of healthy people,suggesting that monocyte subsets may play an important role in the occurrence and development of the disease.2.The proportion of CD14⁺⁺CD16⁺intermediate monocyte subsets may be a biological indicator of SLE disease activity.