Cyclophosphamide-induced liver injury during treatment of interstitial lung disease in juvenile dermatomyositis.

A middle-childhood aged girl with recently diagnosed MDA5+ juvenile dermatomyositis complicated by interstitial lung disease presented with diffuse abdominal pain and scleral icterus following the initiation of cyclophosphamide therapy. A laboratory workup revealed elevated liver enzymes and hyperbilirubinaemia. She was admitted for worsening liver function, and all medications were held with concern for drug-induced liver injury. A workup for infectious and autoimmune causes of transaminitis was negative. A liver biopsy revealed diffuse apoptotic cells without evidence of portal obstruction. A diagnosis of cyclophosphamide-induced liver injury was made. She was initiated on intravenous methylprednisolone with a steroid taper, leading to recovery. Cyclophosphamide was replaced by tofacitinib and abatacept for control of interstitial lung disease, which was well tolerated. Although cyclophosphamide in high doses may cause sinusoidal obstruction syndrome, hepatocellular liver injury is rare. Here to our knowledge, we present the first case report of hepatocellular injury caused by intravenous cyclophosphamide in a paediatric patient with a rheumatic condition.