Fracture Risk Reduction by Bisphosphonates in Mastocytosis?

Abstract

BACKGROUND:

Fragility fractures (FFxs) and osteoporosis are frequent manifestations of indolent systemic mastocytosis (ISM). So far, the effect of antiosteoporotic therapy on FFxs has scarcely been investigated.

OBJECTIVE:

This study evaluates the long-term effect of bisphosphonate treatment on FFxs, bone mineral density (BMD), and bone resorption in patients with ISM in daily clinical practice.

METHODS:

Patients with ISM who received bisphosphonates because of osteoporosis and/or FFxs were retrospectively analyzed (n = 58). Fractures were recorded by vertebral fracture assessment, X-rays of the thoracolumbar spine, medical records, and a questionnaire. Five-year analysis (n = 30) was made by comparing observed 5-year FFx risk with MastFx-predicted FFx risk for patients with ISM not treated with antiosteoporotic drugs and analyzing 5-year change in BMD and serum collagen C telopeptide (sCTx) Z-scores.

RESULTS:

During the median follow-up of 7.3 years, 14 of 58 patients suffered 40 FFxs. Five- and 10-year FFx-free survival were 81.9% (standard error [SE], 5.5%) and 67.0% (SE, 7.7%), respectively. FFx risk was significantly higher in patients with previous vertebral FFxs (P = .004), lower femoral BMD at baseline (P = .042), and history of anaphylaxis (P = .028). No 5-year FFx risk reduction could be proven, possibly due to the small sample size. The lumbar BMD Z-score significantly increased from median (interquartile range [IQR]) -2.20 (-2.80 to -1.50) to -1.50 (-2.30 to -0.60) (P < .001, n = 27). The sCTx Z-score decreased from median 0.71 (IQR, -0.59 to 2.39) to -0.95 (-1.30 to -0.16) (P = .008, n = 15).

CONCLUSION:

Bisphosphonates significantly increase BMD and decrease sCTx in patients with ISM. However, FFxs still frequently occur. Especially patients with previous FFxs remain at high risk of new FFxs.

• Authors: Merel C Onnes, Jasper J van Doormaal, Eveline van der Veer, Joris B Versluijs, Suzanne Arends, Hanneke N G Oude Elberink
• Journal: The journal of allergy and clinical immunology. In practice (J Allergy Clin Immunol Pract) 2020 Nov - Dec Vol. 8 Issue 10 Pg. 3557-3564 ISSN: 2213-2201 [Electronic] United States
• PMID: 32673882 (Publication Type: Journal Article)
• Copyright: Copyright © 2020 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Chemical References

• Diphosphonates

Topics

• Bone Density
• Diphosphonates (therapeutic use)
• Fractures, Bone (epidemiology, prevention & control)
• Humans
• Mastocytosis
• Retrospective Studies
• Risk Reduction Behavior