Antisynthetase Syndrome: The Classical Phenotype With a Twist

Antisynthetase syndrome is a systemic autoimmune rheumatic disease characterized by multiple organ involvement, including interstitial lung disease, myositis, non-erosive arthritis, fever, Raynaud's phenomenon, "mechanic's hands," and the presence of autoantibodies against aminoacyl-tRNA synthetases, mainly anti-Jo1 (histidyl) antibodies. Patients with antisynthetase syndrome and active muscle inflammation are usually presented with elevated creatine phosphokinase levels, even in the range of acute rhabdomyolysis. Despite that, the presence of myoglobinuric acute kidney injury is rarely seen in patients with myositis-associated rhabdomyolysis. Herein, we report the case of a 64-year-old man who presented with acute kidney injury due to severe rhabdomyolysis in the setting of antisynthetase syndrome diagnosed by the classical clinical triad of (1) interstitial lung disease, (2) non-erosive arthritis, and (3) active myositis and the presence of anti-Jo1 antibodies. The diagnosis was confirmed by muscle biopsy histological findings as well as electromyography. In this case report, we also discuss the classical clinical manifestations of antisynthetase syndrome and a twist toward this unusual complication associated with active muscle inflammation.