PMC4047218_01
Characteristic findings associated with clinical and autoantibody phenotypes in myositis. A. Heliotrope, malar rash and facial erythema in pattern of photosensitivity, as seen in this 11-year-old juvenile dermatomyositis patient with anti-p155 autoantibodies.. B. Interstitial lung disease, defined by high-resolution computed tomographic (CT) scanning, is seen frequently in patients with polymyositis, as well as with the anti-synthetase autoantibody phenotype. More recently, rapidly progressive interstitial lung disease has been associated with the CADM-140 autoantibody. The chest CT scan depicted here is from a 55 year old female patient with anti-Jo-1 autoantibodies and interstitial lung disease.. C. Dystrophic calcification, as present around the elbow and forearm here in this 10.5-year-old girl with juvenile dermatomyositis and anti-MJ autoantibodies, is seen in up to 25% of juvenile-onset dermatomyositis and less frequently in adult-onset disease. Calcinosis is present in > 60% of patients with the anti-MJ autoantibody phenotype.. D. Lipodystrophy, loss of subcutaneous fat with frequently associated insulin resistance, diabetes and hypertriglyceridemia, are associated with juvenile-onset dermatomyositis. Generalized lipodystrophy, a widespread loss of fat from the trunk and extremities, has been associated with anti-p155 autoantibodies. A loss of fat from the arm is seen in this 20-year-old woman with juvenile onset dermatomyositis since age 8 years, who has anti-p155 autoantibodies and lipodystrophy.
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She continues to have persistent skin and muscle disease for more than a decade, which includes photosensitive facial rashes (Figure 1A) as well as rashes in the V of the neck and around the shoulders in the distribution of a shawl, widespread erythema, subcutaneous edema, and severe nailfold and gingival capillary changes. Polymyositis, for example, is characterized by moderate to severe weakness, with a high frequency of interstitial lung disease (Figure 1B) and cardiac disease, including heart failure, arrhythmias and ventricular dysfunction in up to 50% of patients, which negatively impact survival.; Patients with adult and juvenile dermatomyositis have mild to moderate weakness, with dystrophic calcification seen in approximately 25% of children and less frequently in adults (Figure 1C). Other characteristic features of dermatomyositis include cutaneous and gastrointestinal ulcerations, which develop from underlying vasculopathy and tissue ischemia, and lipodystrophy (Figure 1D), both of which are more common in children. Anti-p155 autoantibodies, which target TIF-1gamma, have been identified in up to 25% of dermatomyositis and juvenile dermatomyositis patients, and in up to 75% of dermatomyositis patients with malignancy.; Data remain limited on the clinical phenotype associated with this autoantibody, but moderate to severe muscle weakness with classic dermatomyositis skin rashes, as well as more severe cutaneous involvement with a high frequency of ulcerations, erythroderma, subcutaneous edema and generalized lipodystrophy (Figure 1D) have been seen frequently. Anti-MJ autoantibodies, which have been found to target nuclear matrix protein 2 (NXP2), have been seen in up to 25% of adult and juvenile dermatomyositis patients and are associated with a high frequency of calcinosis (Figure 1C), joint contractures, arthritis and an absence of truncal rashes.; A third emerging phenotype is that associated with anti-CADM-140 autoantibodies, which are directed against an RNA helicase known as melanoma differentiation-associated gene 5 (MDA-5); this phenotype has been identified mainly in Japanese patients with amyopathic dermatomyositis and are associated with rapidly progressive interstitial lung disease (Figure 1B).;