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.