Looking at New Unexpected Disease Targets in LMNA-Linked Lipodystrophies in the Light of Complex Cardiovascular Phenotypes: Implications for Clinical Practice.

Variants in LMNA, encoding A-type lamins, are responsible for laminopathies including muscular dystrophies, lipodystrophies, and progeroid syndromes. Cardiovascular laminopathic involvement is classically described as cardiomyopathy in striated muscle laminopathies, and arterial wall dysfunction and/or valvulopathy in lipodystrophic and/or progeroid laminopathies. We report unexpected cardiovascular phenotypes in patients with LMNA-associated lipodystrophies, illustrating the complex multitissular pathophysiology of the disease and the need for specific cardiovascular investigations in affected patients. A 33-year-old woman was diagnosed with generalized lipodystrophy and atypical progeroid syndrome due to the newly identified heterozygous LMNA p.(Asp136Val) variant. Her complex cardiovascular phenotype was associated with atherosclerosis, aortic valvular disease and left ventricular hypertrophy with rhythm and conduction defects. A 29-year-old woman presented with a partial lipodystrophy syndrome and a severe coronary atherosclerosis which required a triple coronary artery bypass grafting. She carried the novel heterozygous p.(Arg60Pro) LMNA variant inherited from her mother, affected with partial lipodystrophy and dilated cardiomyopathy. Different lipodystrophy-associated LMNA pathogenic variants could target cardiac vasculature and/or muscle, leading to complex overlapping phenotypes. Unifying pathophysiological hypotheses should be explored in several cell models including adipocytes, cardiomyocytes and vascular cells. Patients with LMNA-associated lipodystrophy should be systematically investigated with 24-h ECG monitoring, echocardiography and non-invasive coronary function testing.

Endocrine effects of the tyrosine kinase inhibitor vandetanib in patients treated for thyroid cancer.

PURPOSE: The purpose of the study was to assess the endocrine effects of vandetanib, a multikinase inhibitor targeting RET, vascular endothelial growth factor receptor, and epidermal growth factor receptor, in 39 patients with progressive thyroid cancer included in two randomized placebo-controlled trials using vandetanib 300 mg/d. METHODS: Endocrine samplings were performed at baseline and then every 6 months. We compared differences in endocrine parameters between baseline and on vandetanib therapy or placebo. RESULTS: During vandetanib treatment, several changes were observed. 1) Calcium (P = 0.0004) and vitamin D (P = 0.001) mean replacement doses were increased; calcium level remained unchanged, but serum 25(OH) vitamin D level decreased (P = 0.001); and serum PTH (P = 0.01) and 1,25(OH)(2) vitamin D (P = 0.01) levels increased, suggesting a decreased intestinal absorption of vitamin D or lack of sun exposure as a result of photosensitization. 2) l-T(4) doses were increased (P < 0.0001) to maintain serum TSH within the normal range. 3) In male patients, total testosterone (P = 0.048), bioavailable testosterone (P = 0.03), and SHBG (P = 0.02) levels increased. Serum inhibin B decreased (P = 0.02) and stimulated FSH increased (P = 0.006), suggesting a Sertoli cells insufficiency. 4) Cortisol level increased (P = 0.007) as well as ACTH level (P = 0.03) and cortisol-binding globulin (P = 0.02), but free urinary cortisol levels remained in the normal range. None of these changes were observed in patients randomized to the placebo arm. CONCLUSION: In patients with locally advanced or metastatic thyroid cancer, the tyrosine kinase inhibitor vandetanib has several endocrine effects. Thyroid hormone, calcium, and vitamin D analog requirements increased, but consequences of the biological alterations on phosphocalcic metabolism and gonadotrope and adrenal functions are unknown.