title: Long-term pamidronate treatment of polyostotic fibrous dysplasia of bone: A case series in young adults.
abstract: BACKGROUND
  Limited information is available about long-term pamidronate treatment in adults with fibrous dysplasia (FD) of bone.
  
  
  OBJECTIVE
  The aim of this case series was to report the clinical outcomes and the biochemical and densitometric findings in a group of young adult patients with polyostotic FD treated for ≥3 years with IV pamidronate.
  
  
  METHODS
  Pamidronate was administered every 6 months (60 mg/d for 3 days) for 2 years. Thereafter, treatment was individualized. Pamidronate was administered at shorter or longer intervals based on response. Bone pain, radiography, serum bone alkaline phosphatase (BALP) activity, and urinary C-terminal cross-linking telopep-tide of type I collagen (CTX-I) concentration were assessed for a mean of 7 years. Bone mineral density (BMD) of FD areas (FDas) and contralateral areas (CLas) were measured at baseline and at 12 and 24 months. Data were collected prospectively.
  
  
  RESULTS
  Seven patients (5 women, 2 men; mean [SD] age, 31.0 [7.2] years [range, 22-43 years]) were included in the study. Patients received IV pamidronate for a mean of 6.9 years (median, 7.1 years [range, 3.7-10.9 years]). Pamidronate was associated with a reduction in bone pain and a significant reduction in BALP in all patients at the end of follow-up (P < 0.02). The mean reduction from baseline in CTX-I concentration (measured in 3 patients) was 56%; this difference was not significant. Mean BMD values of FDas were significantly increased at 12 months (by 5.9%; P < 0.05) compared with baseline; but was not significantly increased at 24 months (7.3%), probably reflecting a higher dispersion of values due to individual responses to treatment. No significant changes were observed in CLa BMDs. Mean BMD of FDa had a numerically lower decrease of 15.3% compared with CLa at baseline; these decreases with pamidronate were 10.8% at 12 months (P = NS) and 9.3% at 24 months (P < 0.05). Refilling of osteolytic lesions was not observed.
  
  
  CONCLUSIONS
  These patients with FD of bone treated with IV pamidronate long term had improvement in bone pain and BMD. The effectiveness of individualized pamidronate administration in the long-term treatment of FD in adult patients should be investigated in blinded controlled trials.
authors.affiliation: Metabolic Bone Disease Section, University of Buenos Aires Hospital, Buenos Aires, Argentina.
authors.forename: Muriel S
authors.initials: MS
authors.lastname: Parisi
authors.affiliation: Metabolic Bone Disease Section, University of Buenos Aires Hospital, Buenos Aires, Argentina.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Oliveri
keywords: bone alkaline phosphatase; bone markers; bone mineral density; bone pain; fibrous dysplasia; pamidronate