Fibroblast growth factor-23 in patients with systemic sclerosis: A case–control study

BackgroundFibroblast growth factor-23 (FGF-23) is actively involved in phosphate homeostasis and skeletogenesis.Aim of the workTo assess the serum level of FGF-23 in systemic sclerosis (SSc) patients (both diffuse dSSc and limited lSSc subtypes) in order to find if it has a role in the pathogenesis of the disease and study its relation to the clinical manifestations.Patients and methodsThe study included 30 dSSc patients, 30 lSSc and 28 age and sex matched controls. In patients, clinical examination and laboratory investigations were performed and Medsger severity scale assessed. Serum FGF-23 was measured using ELISA.ResultsThe age of dSSc patients was 36.94 ± 9.89 years and the lSSc 38.36 ± 10.04 years. The serum FGF-23 level was 23.44 ± 14.86 pg/ml in dSSc patients, 20.01 ± 13.92 pg/ml in lSSc patients and 23.09 ± 11.45 pg/ml in the control (p = 0.58). No significant difference in the FGF-23 level was found according to the presence of lung fibrosis (p = 0.6). There was no significant difference in FGF levels among patients according to the severity (p = 0.39). In SSc patients there was a significant correlation between FGF and serum phosphorus especially in dSSc patients (r = 0.6, p = 0.003). Serum urea significantly correlated with FGF-23 in those with dSSc (r = 0.46, p = 0.037). There was no significant difference in the FGF-23 levels (p = 0.18) between those with a normal and impaired glomerular filtration rate.ConclusionThe mean serum level of FGF-23 in this study showed no significant difference between systemic sclerosis patients and their subtypes with the normal subjects. It seems to have no role in the clinical manifestations of the disease.