TY - JOUR T1 - Fyn and CD70 Expression in CD4+ T Cells from Patients with Systemic Lupus Erythematosus JF - The Journal of Rheumatology JO - J Rheumatol DO - 10.3899/jrheum.090424 SP - jrheum.090424 AU - Anna Kozlowska AU - Pawel Hrycaj AU - Jan K. Lacki AU - Pawel P. Jagodzinski Y1 - 2009/12/01 UR - http://www.jrheum.org/content/early/2009/11/25/jrheum.090424.abstract N2 - Objective CD4+ T cells from patients with systemic lupus erythematosus (SLE) display defective function that contributes to abnormal activation of B cells and autoantibody production. Methods We compared the transcript and protein levels of Fyn and CD70 in CD4+ T cells from patients with SLE (n = 41) and healthy individuals (n = 34). The CD4+ T cells were isolated by positive biomagnetic separation technique. The quantitative analysis of messenger RNA was performed by reverse transcription and real-time quantitative PCR. The protein contents in the CD4+ T cells were determined by Western blotting analysis. Results We observed significantly higher levels of Fyn (p = 0.03) and CD70 (p = 0.029) transcripts in SLE CD4+ T cells than in controls. There was a significant increase in CD70 protein levels (p < 0.0001), but not Fyn protein levels (p = 0.081) in CD4+ T cells from patients with SLE compared to healthy individuals. In the group with high disease activity [SLE Disease Activity Index (SLEDAI) ≥ 9], we observed a significantly higher Fyn protein content than in controls (p = 0.030). There was no correlation between Fyn and CD70 protein levels in SLE CD4+ T cells and disease activity as expressed in the SLEDAI scale. Conclusion We confirmed previous observations of higher expression of CD70 in CD4+ T cells from patients with SLE. Our findings suggest that increased Fyn protein content in CD4+ T cells can be associated with high SLE disease activity. ER -