Significado clínico del aumento de los valores séricos de FGF-23 en la displasia fibrosa / Clinical significance of increased serum levels of FGF-23 in fibrous dysplasia

Introducción y objetivo: La displasia fibrosa (DF) puede asociarse al desarrollo de osteomalacia hipofosfatémica por la producción de FGF-23 en el tejido óseo displásico. En este estudio se analizan los valores de FGF-23 en pacientes con DF y su relación con la actividad de la enfermedad y con los valores de fosfato sérico. Pacientes y métodos: Se incluyó a 12 pacientes adultos con DF. Se revisaron las características clínicas, los parámetros analíticos y los tratamientos realizados y su relación con los valores de FGF-23. Resultados: Seis de 12 pacientes (50%) tenían un aumento del FGF-23; estos pacientes tenían una edad, una extensión y una actividad de la enfermedad similares a aquellos con FGF-23 normal. No se observaron diferencias entre los valores de fosfato sérico entre ambos grupos (FGF-23 alto: 3,9±0,9mg/dl vs. FGF-23 normal: 3,5±0,6mg/dl). Ningún paciente con aumento de FGF-23 tenía valores de fosfato sérico bajos. Conclusión: Los pacientes adultos con DF presentan con frecuencia un aumento del FGF-23 sin repercusión en los niveles séricos de fosfato, lo que indica una alteración en el procesamiento de esta proteína en el tejido óseo displásico en esta patología

Introduction and objective: Fibrous dysplasia (FD) can be associated with the development of hypophosphatemic osteomalacia, caused by the production of FGF-23 by dysplastic bone tissue. This study analysed FGF-23 levels in patients with FD, and their association with disease activity and serum phosphate values. Patients and methods: Twelve adult patients with FD were included in the study. Clinical history, disease extension and activity and treatments received were reviewed, and the relationship of those values with FGF-23 and serum P levels was analysed. Results: FGF-23 was elevated in 6/12 patients (50%). Patients with high FGF-23 levels had similar age and disease activity and extension than those who did not. No differences were observed in serum phosphate values between both groups (increased FGF-23: 3.9±0.9 mg/dl vs. decreased FGF-23: 3.5±0.6 mg/dl). In fact, none of the patients with increased FGF-23 had low serum phosphate values. Conclusion: Adult FD patients frequently present elevated FGF-23 values with no serum phosphate level repercussion, suggesting an alteration in the processing of this protein in the dysplastic bone tissue for this pathology

Clinical significance of increased serum levels of FGF-23 in fibrous dysplasia. / Significado clínico del aumento de los valores séricos de FGF-23 en la displasia fibrosa.

INTRODUCTION AND OBJECTIVE: Fibrous dysplasia (FD) can be associated with the development of hypophosphatemic osteomalacia, caused by the production of FGF-23 by dysplastic bone tissue. This study analysed FGF-23 levels in patients with FD, and their association with disease activity and serum phosphate values. PATIENTS AND METHODS: Twelve adult patients with FD were included in the study. Clinical history, disease extension and activity and treatments received were reviewed, and the relationship of those values with FGF-23 and serum P levels was analysed. RESULTS: FGF-23 was elevated in 6/12 patients (50%). Patients with high FGF-23 levels had similar age and disease activity and extension than those who did not. No differences were observed in serum phosphate values between both groups (increased FGF-23: 3.9±0.9 mg/dl vs. decreased FGF-23: 3.5±0.6 mg/dl). In fact, none of the patients with increased FGF-23 had low serum phosphate values. CONCLUSION: Adult FD patients frequently present elevated FGF-23 values with no serum phosphate level repercussion, suggesting an alteration in the processing of this protein in the dysplastic bone tissue for this pathology.