Complement-mediated thrombogenic vasculopathy in COVID-19.

Abstract

We present the case of a 61-year-old woman who attended the Emergency Department with fever, tachypnea, abdominal discomfort, pain, and coldness in the right lower leg suggestive of ischemia. Her medical history included hypertension treated with losartan and depression, with a recent history of cognitive impairment. Capillary plexus (Fig. 1c) was noted. Autoantibody studies showed a positive direct Coombs test, and direct antibody testing was positive for C3. Anticardiolipin, anti–b2-glycoprotein antibodies, and lupus anticoagulant were all negative. Physical examination revealed punctiform purpura on the arms and lower legs (Fig. 1a). Peripheral pulses in the right leg were absent. Oxygen saturation (SaO2) was 98% on air, and blood pressure was 70/56 mmHg. Laboratory values included hemoglobin 8.1 g/dl (1216.5); 14,600 white blood cells/µl (4,000–11,500); creatinine 3 mg/dl (0.43–0.96); D-dimer level 5,977 ng/ml (220–500); LDH 281 U/liter (120–246); elevated C-reactive protein 279 mg/l; and troponin I 128 ng/l (3–58). The platelet count, prothrombin, and activated partial thromboplastin times were all normal. Doppler ultrasound showed complete occlusion of the right common femoral artery, requiring supracondylar amputation.