When your immune system falls out with your heart: an important lesson on antisynthetase myocarditis

A 57-year-old special Olympics athlete presented with subacute onset dyspnoea. Baseline investigations revealed troponin T rise and an abnormal ECG, which prompted coronary angiography. This was unremarkable, as was his transthoracic echocardiography (TTE). He re-presented 7 months later with progressive dyspnoea associated with significant weight loss, peripheral oedema and intermittent fevers. Examination revealed bilateral fine end-inspiratory crackles, peripheral oedema and fever. Investigations revealed elevated troponin T and raised inflammatory markers. ECG remained unchanged, whereas TTE revealed mild global impairment of left ventricular function. Chest radiography was suggestive of extensive interstitial lung disease, which was confirmed by high resolution CT. Presence of interstitial lung disease and myocarditis raised the suspicion of a systemic inflammatory condition. Subsequently, an autoimmune screen was positive for anti-Jo-1 antibody associated with antisynthetase syndrome. He was treated with high-dose steroids and rituximab with dramatic symptomatic improvement and immediate fall in troponin T level.