Effects of teriparatide on bone mineral density and quality of life in Duchenne muscular dystrophy related osteoporosis: a case report.

Duchenne muscular dystrophy (DMD) is an X-linked recessive muscle disease characterized by secondary osteoporosis and increased fractures. We describe the case of a 20-year-old boy with DMD suffering from back pain due to multiple vertebral fractures who was treated with teriparatide. Improvement of bone density, pain, and quality of life was achieved. DMD is an X-linked recessive muscle disease with secondary osteoporosis and related frequently occurring fractures. To date, only bisphosphonates have been used to treat osteoporosis in DMD. Black bear parathyroid hormone has been previously reported to enhance bone mass in the dystrophin-deficient mouse. This study reports the positive effect of osteoanabolic treatment with once-daily recombinant human parathyroid hormone 1-34 (rhPTH 1-34, teriparatide) in a 20-year-old DMD boy suffering from multiple vertebral fractures causing back pain. Bone formation and resorption markers (osteocalcin and C-telopeptide of type I collagen, respectively), as expected, increased within 6 months and intensity of back pain early decreased, with no pain reported after 6 months at visual analog scale. Over a 18-month period of treatment with teriparatide, bone mineral density and quality of life, assessed by the 36-item short-form questionnaire, considerably improved and no side effects were reported. Further studies on large cohorts are warranted to test the efficacy of this promising treatment for DMD related osteoporosis.

MYH7-related myopathies: clinical, histopathological and imaging findings in a cohort of Italian patients.

BACKGROUND: Myosin heavy chain 7 (MYH7)-related myopathies are emerging as an important group of muscle diseases of childhood and adulthood, with variable clinical and histopathological expression depending on the type and location of the mutation. Mutations in the head and neck domains are a well-established cause of hypertrophic cardiomyopathy whereas mutation in the distal regions have been associated with a range of skeletal myopathies with or without cardiac involvement, including Laing distal myopathy and Myosin storage myopathy. Recently the spectrum of clinical phenotypes associated with mutations in MYH7 has increased, blurring this scheme and adding further phenotypes to the list. A broader disease spectrum could lead to misdiagnosis of different congenital myopathies, neurogenic atrophy and other neuromuscular conditions. RESULTS: As a result of a multicenter Italian study we collected clinical, histopathological and imaging data from a population of 21 cases from 15 families, carrying reported or novel mutations in MYH7. Patients displayed a variable phenotype including atypical pictures, as dropped head and bent spine, which cannot be classified in previously described groups. Half of the patients showed congenital or early infantile weakness with predominant distal weakness. Conversely, patients with later onset present prevalent proximal weakness. Seven patients were also affected by cardiomyopathy mostly in the form of non-compacted left ventricle. Muscle biopsy was consistent with minicores myopathy in numerous cases. Muscle MRI was meaningful in delineating a shared pattern of selective involvement of tibialis anterior muscles, with relative sparing of quadriceps. CONCLUSION: This work adds to the genotype-phenotype correlation of MYH7-relatedmyopathies confirming the complexity of the disorder.

Duchenne muscular dystrophy and epilepsy.

Cognitive and behavioral difficulties occur in approximately a third of patients with Duchenne muscular dystrophy. The aim of our study was to assess the prevalence of epilepsy in a cohort of 222 DMD patients. Epileptic seizures were found in 14 of the 222 DMD patients (6.3%). The age of onset ranged from 3 months to 16 years (mean 7.8). Seizures were more often focal epilepsy (n=6), generalized tonic-clonic seizures (n=4) or absences (n=4). They were present in 12 of the 149 boys with normal IQ (8.1%) and in two of the 73 with mental retardation (2.7%). In two cases the parents did not report any past or present history of seizures but only 'staring episodes' interpreted as a sign of 'poor attention'. In both patients EEG showed the typical pattern observed in childhood absence epilepsy. Our results suggest that the prevalence of epilepsy in our study (6.3%) is higher than in the general pediatric population (0.5-1%). The risk of epilepsy does not appear to increase in patients with mental retardation.

ANT1 is reduced in sporadic inclusion body myositis.

To investigate ANT1 and NF-κB expression in inclusion body myositis (IBM) muscle and to verify their possible roles in the pathogenesis of the disease, we collected muscle samples from five patients with IBM, polimyositis (PM) and controls. p65 form of NF-κB was analyzed using immunocytochemistry, Western blot and EMSA. Western blot of ANT1 was performed and confirmed by gene expression study. Mann-Whitney test was used for groups comparisons. NF-κB (p65) was found over-expressed both with western blot and EMSA, either in IBM or PM patients versus controls (p < 0.01). Expression of ANT1 were lower in IBM samples versus both PM and controls (p < 0.01). ANT1 reduction and NF-κB over-expression in IBM muscle could explain the lack of apoptosis in such disease. Normal ANT1 expression in PM could be related to the scarcity of mitochondrial abnormalities in the disease, but it could also suggest that these two conditions diverge in activating different anti-apoptotic pathways.

Activation of NF-kappaB pathway in Duchenne muscular dystrophy: relation to age.

Muscle degeneration in Duchenne muscular dystrophy (DMD) is exacerbated by increased oxidative stress and the endogenous inflammatory response, with a key role played by nuclear factor kappa-B (NF-kappaB) and other related factors such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-6. However the time course of expression of these molecules and the relation with the amount of necrosis and regeneration have never been investigated. The expression of NF-kappaB, the cytokines TNF-alpha and IL-6 and the antioxidant enzyme glutathione peroxidase (GPx) was studied in muscle samples from 14 patients with DMD aged between 2 and 9 years. Moreover a quantitative morphological evaluation was performed to evaluate necrotic and regenerative areas. The highest percentage of necrosis was revealed within 4 years of age, with a significant negative correlation with age (p < 0.003), which paralleled to a significant decrement of regenerating area (p < 0.0004). We reported the novel observation that the number of NF-kappaB positive fibers and the NF-kappaB DNA-binding activity, revealed by EMSA, are high at two years of life and significantly decline with age (p < 0.0005 and p < 0.0001). The expression of TNF-alpha, IL-6 and GPx was upregulated in DMD muscles compared to controls and significantly increased with age on real-time PCR analysis (p < 0.0002; p < 0.0005; p < 0.03 respectively) and ELISA (p < 0.002; p < 0.02; p < 0.0001 respectively). Since anti-inflammatory and anti-oxidant drugs are nowadays being translated to clinical studies in DMD, the reported insights on these therapeutic targets appear relevant. Further studies on the interactions among these pathways in different DMD phases and on the response of these cascades to treatments currently under investigation are needed to better elucidate their relevance as therapeutic targets.