Intravenous Pamidronate Improved Bone Mineral Density and Diminished Bone Turnover in Patientswith Fibrous Dysplasia

MS PARISI; MB OLIVERI; C TAU; C GÓMEZ ACOTTO; F SOLÍS; C MAUTALEN

Phoenix

Congreso; XXIII Congreso Anual de la ASBMR; 2001

American Society for Bone and Mineral Research

We report the effect of one year treatment with intravenous Pamidronate (APD) on bone mineral density(BMD) and biochemical markers of bone turnover in six patients with Fibrous Dysplasia (FD), 5 womenand 1 man. Mean age was 37.3 years (r:21-79). A complete clinical, biochemical, scintigraphic andradiographic follow-up was performed. BMD of Total Body (TB) was assessed by DEXA at baseline andone year after the onset of treatment. In patients with unilateral location of the disease, areas of FD (aFD)(3 located in the arms, 5 in legs and 1 in pelvis) were delimited by ROI analysis and compared with theircontralateral non-affected side (C). The difference in BMD was calculated as a percentage where thehealthy side was taken as 100%. The same analysis was performed in 6 sex and age matched controls.Bone alkaline phosphatase (BAP) and urinary cross-laps (CTX) were measured at baseline and at 3months intervals. A 60mg/day dose of iv APD was administered on 3 consecutive days every 6 months.At baseline, TB BMD values were in the normal range, except for one postmenopausal woman whopresented diminished BMD. Mean difference in BMD (ROI analysis) between aFD and C was -8.4% (r:-36.2 to +4.6). The difference in BMD between right and left sides in control subjects was+0.5±4.3(X±SD). BAP and CTX levels were above the normal range in 5 and 3 patients respectively.After one year, we observed 2.6% increments in mean TB BMD (p<0.05), while mean BMD of aFD andC increased 6.9% and 1.9% respectively. The mean difference between aFD BMD and C BMDdiminished to –4.8% (r:-31.5 to +19.5). BAP levels were found to decrease an average 30% in the fivepatients presenting abnormal baseline values, but were still above the normal range. BAP levelsremained unchanged in the patient with normal baseline values. CTX levels decreased in the threepatients presenting abnormal baseline values. Only one patient with markedly high baseline values stillshowed high levels of CTX after one year of treatment, although a 40 % reduction was observed. CTXlevels remained unchanged in the patients with normal baseline values.Whereas Total Body BMD was mostly within normal ranges, BMD of FD areas was lower than theircorresponding healthy contralateral side. Treatment with iv APD produced an increase in Total Body andareas of FD BMD and diminished markers of bone turnover. Our results lead to the conclusion thatspecific densitometric evaluation of areas of FD by means of ROI analysis, together with determinationsof specific markers of bone turnover allow to assess the effectiveness of one year treatment with iv APDin most patients with FD.