Changes And Significance Of Follicular Regulatory T Cells In Peripheral Blood Of RA Patients

ObjectiveTo observe the percentage and number of follicular regulatory T cells(Tfr)in peripheral blood of patients with rheumatoid arthritis(RA),and to observe the changes in the percentage and number of Tfr cells in peripheral blood of RA patients.To analyze the significance of the changes of Tfr cell in peripheral blood of RA patients,by comparing the percentage and number of Tfr cells in peripheral blood of RA patients with different clinical stages.Methods(1)Peripheral blood of patients with rheumatoid arthritis was collected,and the percentages and numbers of Tfr,Treg and Tfh cells were detected by flow cytometry.(2)The clinical information of RA patients was collected,and the score of DAS28was calculated.According to the DAS28 score of RA patients,the activity of RA patients was staged and divided into active period and remission period.The changes of the percentages of Tfr,Tfh and Treg cells and the ratio of Tfr/Treg and Tfr/Tfh cells in peripheral blood of patients with RA during active and remission were analyzed.(3)The correlation between the clinical diagnostic indicators such as DAS28score,rheumatoid factor level and anti-cyclic citrullinated peptide antibody level in RA patients and the percentage of Tfr cells in peripheral blood was analyzed.(4)The level of IL-7 in the serum of RA patients was measured and the correlation between IL-7 levels and the percentages of Tfr cell was analyzed.Results(1)The percentages of Tfr,Tfh and Treg cells in peripheral blood of healthy control(HC)group were(0.26±0.05)%,(3.63±0.55)%,(5.28±0.37)%,respectively.The percentages of Tfr,Tfh and Treg cells in peripheral blood of RA patients were(0.49±0.09)%,(5.51±0.66)%,(6.23±0.45)%,respectively.Compare with HC,the percentages of Tfh and Tfr cells in peripheral blood of RA patients increased(P<0.05),while the percentage of Treg cells did not show obvious abnormalities.The number of Tfr,Tfh and Treg cells in peripheral blood of HC group were(3.912±0.69)×10~5/L,(6.86±0.98)×10~6/L,(1.09±0.12)×10~7/L,respectively.The number of Tfr,Tfh and Treg cells in peripheral blood of RA patients.They were3.26±0.61)×10~5/L,(6.04±0.92)×10~6/L,and(6.88±1.16)×10~6/L,respectively.Compare with HC,there were no abnormalities in the number of Tfh and Tfr cells in the peripheral blood of RA patients,but the number of Treg cells decreased significantly(P<0.05).(2)Compare with HC,the percentages of Tfr and Tfh cells in peripheral blood of patients with RA during active or remission period increased significantly(P<0.05,P<0.05),while the percentages of Treg cells did not show obvious abnormalities.Compare with HC,there were no significant abnormalities in the number of Tfr and Tfh cells in the peripheral blood of patients with active or remission,but the number of Treg cells was significantly reduced(P<0.05).Compare with HC,there was a significant increase in the ratio of Tfr/Tfh and Tfr/Treg in RA patients during the remission period(P<0.05,P<0.05),but there was no significant abnormality in the ratio of Tfr/Tfh and Tfr/Treg in active RA patients.(3)The DAS28 score,rheumatoid factor level,anti-cyclic citrullinated peptide antibody level in RA patients was negatively correlated with the percentage of Tfr cells in peripheral blood(r=-0.3533,P=0.0404;r=-0.3419,P=0.0478;r=-0.4366,P=0.0078).(4)Serum IL-7 levels in the HC group,active RA patients,and remission RA patients were(54.79±2.70)pg/ml,(45.54±1.44)pg/ml,(42.76±1.13)pg/ml.Serum IL-7 levels were decreased in patients with active and remission RA(P<0.05),and serum IL-7 levels were significantly lower in patients with RA during remission(P<0.05).The percentage of Tfr cells in peripheral blood of RA patients was negatively correlated with the level of IL-7 in serum(r=-0.5392,P=0.0249).Conclusions(1)The percentage of Tfr cells in peripheral blood of patients with RA increased,and the level of rheumatoid factor as well as anti-cyclic citrullinated peptide antibody in RA patients were negatively correlated with the percentage of Tfr cells in peripheral blood,suggesting that Tfr cells participate in the development of RA patients.(2)Compared with active RA patients,the percentage of Tfr cells and the ratio of Tfr/Tfh cells in peripheral blood of remission RA patients increased significantly,and the DAS28 score of RA patients was negatively correlated with the percentage of Tfr cells in peripheral blood,suggesting Tfr cells and the relief of the RA patient's condition is closely related.