<prompt> A 10-year-old girl complains of persistent redness of the skin over her knuckles and around the nail beds. She describes easy fatigability and can rise only with difficulty from a squatting position. Physical examination reveals erythema over the knuckles and a heliotropic rash. A muscle biopsy shows infiltrates of B and T lymphocytes around blood vessels and in connective tissue of the perimysium. Elevated serum levels of which of the following would be expected in this patient?Alkaline phosphataseAlpha-fetoproteinCarcinoembryonic antigenCreatine kinase  <response>: Creatine kinase. The inflammatory myopathies represent a heterogeneous group of acquired disorders, all of which feature symmetric proximal muscle weakness, increased serum levels of muscle-derived enzymes, and non-suppurative inflammation of skeletal muscle. They are thought to have an autoimmune origin. The most common morphologic characteristics in the inflammatory myopathies are 1 inflammatory cells, 2 necrosis and phagocytosis of muscle fibers, 3 a mixture of regenerating and atrophic fibers, and 4 fibrosis. Dermatomyositis is distinguished from the other myopathies i.e., polymyositis and inclusion body myositis by the presence of a characteristic heliotropic rash on the upper eyelids, face, and trunk. Patients with inflammatory myopathies have increased serum levels of creatine kinase and other muscle enzymes. Elevated serum alkaline phosphatase choice A is associated with liver and bone disease. Alpha-fetoprotein and carcinoembryonic antigen choices B and C are markers of neoplasia. Elevated blood urea-nitrogen choice E is associated with renal disease.Diagnosis: Dermatomyositis 