Bone Turnover in Children and Adolescents with McCune-Albright Syndrome Treated with Pamidronate for Bone Fibrous Dysplasia

Abstract

Bone fibrous dysplasia is one of the main features of McCune-Albright syndrome, a rare genetic condition caused by constitutive activating mutations of Gs-protein and defined by skin dysplasia, bone fibrous dysplasia, and autonomous multiple endocrinopathies. Raised serum alkaline phosphatase (ALP) and urinary hydroxyproline levels indicating bone metabolic hyperactivity have been reported in these patients. Encouraging therapeutic results have been achieved, mainly in adults, with pamidronate, an aminobisphosphonate. In this study we investigate newer bone metabolic indices in a cohort of 11 children and adolescents treated with pamidronate. Tenfold increases of bone ALP and urinary pyridinoline cross-links were found and osteocalcin levels were twofold higher compared with reference values. After treatment, significant decreases in bone ALP and cross-links (Wilcoxon test P < 0.06) were found. Bone mineral density (BMD) significantly increased during treatment. There were signs of radiological healing as thickening of the cortical bone was found in some cases.

Prognosis for craniofacial fibrous dysplasia after incomplete resection: age and serum alkaline phosphatase

“…The authors have also taken into consideration that their theory might leave room for controversy regarding high serum ALP levels in patient who underwent surgery before the age of 17 years. Children may have higher levels of serum ALP than adults, even in the normal situation; studies have shown a correlation between serum ALP and growth spurts in children, in which hormones play a crucial role 10 . The authors refute such arguments because the serum ALP level begins to drop until it reaches the normal adult level by the age of 11-12 years in females and 13-14 years in males and in this study, most patients received surgery after these ages.…”

An extensive hemimelic polyostotic fibrous dysplasia: a case report

“…Pamidronate is well tolerated and has a good safety profile; it also improves the radiographic appearance of lesions and increases BMD of affected areas [13][14][15]. Our case illustrates the dramatic improvement of FD lesions with the use of pamidronate.…”

Risque d’ostéonécrose des maxillaires associé à un traitement par biphosphonates dans l’enfance

“…La cicatrisation osseuse a été obtenue en l'absence de toute précaution particulière. À noter qu'à l'époque (2009) où le traitement orthodontique a débuté et où la pré-molaire n°14 a été extraite, la recommandation de l'ANSM était déjà connue des praticiens (2007) Cette patiente a reçu des BP entre 7 et 11 ans, âges spé-cifiques quant au turnover cellulaire, puisque les BP diminuent ce turnover cellulaire mais augmentent la densité osseuse, notamment chez les enfants atteints de DF avec le syndrome de Mc-Cune-Albright [30]. Les BP sont de puissants inhibiteurs de l'activité ostéoclastique mais peuvent aussi diminuer la micro-circulation osseuse par activité anti-angiogénique, ce qui constitue un facteur local incontestable d'un possible retard de cicatrisation [18].…”