Objective:To investigate the expression of FAS receptor on idiosyncratic T cell subsets

including TCRαβ+cells

CD4-CD8-cells and TCRαβ+CD4-CD8-T cells

and to discuss the relationship between FAS-mediated apoptosis and peripheral TCRαβ+CD4-CD8-T cells in patients with rheumatoid arthritis(RA).Methods:Totally 24 RA patients and 24 normal controls were included.Flow cytometry was used to detect the percentages of T cell subsets and the expression of FAS receptor.The relationships between the percentages of T cell subsets and the expression of FAS receptor with RF

WBC

CRP and ESR were analyzed respectively by spearman relativity analysis.Results:The percentages of peripheral TCRαβ+ cells and CD4-CD8-cells from RA patients were similar to those in normal controls (P>0.05).Strikingly higher levels of TCRαβ+CD4-CD8-T cells in the peripheral blood of RA patients were detected compared with those in normal controls (0.82±0.38 vs.0.57±0.26

P=0.013).The expressions of FAS receptor on TCRαβ+CD4-CD8-T cells were significantly increased in RA patients compared with those in normal controls (1.23±0.69 vs.0.80±0.45

P=0.016).Positively relationship was found between TCRαβ+CD4-CD8-T cells and TCRαβ+CD4-CD8-FAS+ cells(r=0.809

P=0.000).There was no significant relationship between the percentages of TCRαβ+CD4-CD8-Tcells

the level of FAS receptor expression and RF

WBC

CRP or ESR

respectively.TCRαβ+ cells as well as CD4-CD8- cells had no significant association with RF

WBC

CRP and ESR

respectively.Conclusion: The preliminary results suggest that the significantly upregulated percentages of DNT cells and its FAS receptor expression may increase the sensitivity to FAS-mediated apoptosis.It may lead to the imbalance of immune respective T cells in RA patients.There is no significant relationship between the percentages of TCRαβ+CD4-CD8-T cells

FAS receptor and the indicators of disease activity

though the percentages of them are markedly increased in the Chinese RA patients.The role of TCRαβ+CD4-CD8-T cells in the pathogenesy of RA patients remains to be further studied.