RESUMO
Fibrous dysplasia of bone (FD) is a rare congenital bone disease, characterized by a fibrous component in the bone marrow. Periostin has been extensively researched because of its implication in various fibrotic or inflammatory diseases. Periostin may be associated with the burden or the severity of FD. The case control PERIOSDYS study aimed at assessing serum periostin levels in FD patients. Sixty four patients with monostotic or polyostotic disease were included, in order to evaluate whether the concentrations were greater in patients than in 128 healthy age, BMI and sex-matched controls and if they were more elevated in patients with the more severe phenotypes. We found that periostin levels were greater in patients with FD compared to controls (meanâ¯=â¯1085 vs 958â¯pmol/l, pâ¯=â¯0.026), especially in those with a history of fracture (meanâ¯=â¯1475 vs 966â¯pmol/l, pâ¯=â¯0.0005), polyostotic forms (meanâ¯=â¯1214 vs 955â¯pmol/l, pâ¯=â¯0.004) or McCune-Albright syndrome (meanâ¯=â¯1585 vs 1023â¯pmol/l, pâ¯=â¯0.0048). In contrast, high pain levels were not associated with periostin levels (meanâ¯=â¯1137 vs 1036â¯pmol/l, pâ¯=â¯0.445). Furthermore, patients undergoing bisphosphonate therapy had significantly lower levels than treatment naïve patients (meanâ¯=â¯953 vs 1370â¯pmol/l, pâ¯=â¯0.002). In conclusion, periostin may be a biochemical marker indicative of the most severe forms of FD and could be used to monitor patients treated with bisphosphonates.