Prevalence of Fc-gammaR chain expression in CD4+ T cells of patients with systemic lupus erythematosus

Objective: To determine the upregulation of transcript and protein levels of the T cell receptor (TCR)/CD3-Fc-gammaR chain in CD4(+) T cells of systemic lupus erythematosus (SLE) patients with different clinical disease activity scored on the SLE Disease Activity Index (SLEDAI) scale. Methods: CD4(+) cells were isolated by the positive biomagnetic separation technique. Quantitative analysis of Fc-gammaR cDNA was carried out by using the real-time quantitative polymerase chain reaction (RQ-PCR) SYBR Green I system. Protein levels of Fc-gammaR in CD4(+) T cells were determined by Western blotting analysis. Results: We observed significantly higher transcript and protein levels of the Fc-gammaR chain in CD4(+) T cells of SLE patients ( n=45) than in healthy individuals (n=26). The increase in Fc-gammaR expression was observed in 97.8% of SLE patients. Spearman statistical analysis suggests that the protein level of Fc-gammaR in CD4(+) T cells may correlate with SLE activity scored by the SLEDAI scale (R=0.556, p<0.00006, respectively). Conclusion: The high prevalence of the Fc-gammaR chain in CD4(+) T cells of SLE patients may indicate an important role for this molecule in the pathogenesis of SLE.