Levels of EGF and VEGF in patients with primary and secondary Sjogren's syndrome

Background. Aberrant angiogenesis plays a role in the pathogenesis of Sjogren's syndrome (SS). Objectives. The aim of this study was to compa re the levels of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) in stimulatory parotid saliva and in serum in healthy subjects (HS), patients with primary SS (pSS) and secondary SS (sSS) and to evaluate the expression of EGF, proangiogenic VEGF(1)(65) and antiangiogenic VEGF(1)(65)b mRNA isoforms. Additionally, we determined the sa livary levels of serine/arginine splicing factor (SRSF1), which regulates VEGF(1)(65 )and VEGF(1)(65)b expression. Material and methods. The study comprised 34 women (16 with pSS and 18 with sSS) and healthy subjects for blood and saliva sampling. EGF and VEGF levels in saliva and serum and salivary SRSF1 levels were determined by enzyme-linked immunosorbent assay (ELISA). The expression of VEGF(1)(65), VEGF(1)(65)b and EGF in peripheral blood mononuclear cells (PBMC) was evaluated by quantitative polymerase chain reaction (qPCR). Results. There were no differences in the levels of EGF, VEGF, SRSF1 and in the expression of the EGF, VEGF(1)(65) and VEGF(1)(65)b between HS and SS patients, or between pSS and sSS patients. The salivary levels of VEGF(1)(65) and EGF were significantly higher in pSS, sSS and HS than serum levels. Levels of SRSF1 correlated positively with VEGF and EGF levels. Levels of EGF, VEGF and SRSF1 correlated with each other. Conclusions. The balance of VEGF isoforms is not disturbed in SS. Saliva is more sensitive for the detection of EGF and VEGF than serum, but salivary levels of those proteins are not representative for SS.