The first experience of denosumab therapy on patients with Ehlers-Danlos syndrome and osteoporosis: detailed observation of two patients.

Previous studies have shown decreased bone mineral density (BMD) due to an unknown mechanism in Ehlers-Danlos Syndrome (EDS) patients and described approaches to treatment for osteoporosis in EDS. To date, however, there is no established method of treatment. In this study, we investigated two patients with EDS to clarify the efficacy and safety of denosumab treatment in EDS patients with osteoporosis. We retrospectively enrolled two EDS patients with osteoporosis who underwent denosumab therapy. Patient 1 was a 59-year-old male with classical EDS and osteoporosis who received a 48-month course of denosumab therapy. His lumbar BMD and total hip BMD were 1.335 g/cm2 and 0.762 g/cm2 before treatment, respectively. Forty-eight months later, the lumbar and total hip BMD showed gains of 1.6% and 11.4%, respectively. Patient 2 was a 42-year-old male with vascular EDS and osteoporosis who received an 18-month course of denosumab therapy. His lumbar BMD and total hip BMD were 0.763 g/cm2 and 0.583 g/cm2 before treatment, respectively. Eighteen months later, the lumbar and total hip BMD showed gains of 5.0% and 1.8%, respectively. No fractures or other complications were recorded during the observational period in both cases. This is the first experience of denosmab therapy on patients with EDS and osteoporosis. Denosumab, administered safely with no serious adverse effects such as fractures, exerted a fluctuating but probably positive effect regarding BMD and could be a treatment option on these patients.