Efficacy of denosumab in two cases with multiple-system atrophy and osteoporosis.

Background: Multiple-system atrophy (MSA) is an α-synucleinopathy with a very aggressive course and poor prognosis, which lacks efficient treatment. Thus, MSA represents a serious health and social problem. Progressive stridor and acute laryngeal obstruction likely occur in MSA; however, little is known about the bone metabolism or efficacy of bone absorption drugs, such as denosumab, in osteoporosis with MSA.

Case presentation and methods: Two male patients with osteoporosis in MSA presented to our institution (at 54 and 68 years of age). Denosumab was started after the diagnosis of osteoporosis in MSA, and the therapy was continued for 18-24 months.

Results: Lumbar and hip bone mineral density showed a 3.5% and 0.6% increase at 24 months or a 10.3% and 3.2% increase at 18 months, respectively. Bone turnover markers were also improved in the two cases during follow-up. No fractures or other complications were recorded during the observation period.

Conclusion: This is the first study describing osteoporosis in two patients with MSA being treated by osteoporotic treatment. Based on our findings, it can be concluded that denosumab may be an effective therapy for osteoporosis in MSA.