Melissaropoulos K, et al. - In patients with systemic sclerosis (SSc), the phenotype and intracellular signaling events of B cells were explored. Authors examined the levels of intracellular kinases Lyn, Syk and P-Y 348 Syk along with phosphatase SHP-1 with Western immunoblotting in selected patients. In B cells from a small sample of patients, an arithmetic association of low CD22 expression with kinase Lyn underexpression was noted. Results suggested a probable contribution of CD22 underexpression and impaired phosphorylation along with implications for Lyn kinase aberrations in the activated B cell phenotype in SSc.