p56(lck) activity and expression in peripheral blood lymphocytes from patients with systemic lupus erythematosus

In this study we analyzed the activity and the expression of p56(lck) prote in tyrosine kinase in peripheral blood lymphocytes (PBLs) from systemic lup us erythematosus (SLE) patients and from healthy donors. The p56(lck) activ ity, determined by a non-radioactive Tyrosine Kinase Assay Kit, was signifi cantly higher in active SLE PBLs and discriminated this group of patients f rom inactive SLE patients (p = 0.002) and healthy donors (p = 0.009), p56(l ck) level decreased in SLE lymphocytes (especially for inactive SLE lymphoc ytes, p = 0.005) when compared to healthy donors. These differences were al so reflected by the specific activity of p56(lck) that was clearly elevated in active SLE lymphocytes when compared to inactive SLE (p = 0.022) or hea lthy donors lymphocytes (p = 0.006), A positive correlation between the act ivity of p56(lck) and the tyrosine phosphorylation level in active SLE lymp hocytes was found.