Systemic capillary leak syndrome after ChAdOx1 nCOV-19 (Oxford–AstraZeneca) vaccination

A 66-year-old man presented to the emergency department with a 1-day history of generalized malaise, nausea, abdominal pain and dizziness. On presentation the patient’s body temperature was 36.5°C, blood pressure 112/78 mm Hg, heart rate 112 beats/min and oxygen saturation 96% (room air), and his respiratory rate was normal. He reported no allergies, no drug or alcohol misuse, and no current use of any medications or over-the-counter products. Two days earlier, he had received his first dose of the ChAdOx1 nCOV-19 (Oxford– AstraZeneca) vaccine. The patient’s medical history included monoclonal gammopathy of uncertain significance (immunoglobulin G [IgG] κ) and a cardiac arrest in 2017. At that time, he presented with generalized weakness and a syncopal episode. Because his hemoglobin level was elevated (210 [normal 130–180] g/L), polycythemia was suspected and phlebotomy was performed. Soon after, the patient became hypotensive and went into pulseless electrical activity arrest. He was successfully resuscitated, recovered without substantial deficits and was discharged home 5 weeks later. His test result for influenza type A was positive, and his shock was attributed to the viral infection. At this presentation, the patient’s hemoglobin level was increased markedly at 224 g/L. He had hypoalbuminemia (28 [normal 34–55] g/L) and an elevated creatinine level (133 [normal 62–115] μmol/L). Coagulation parameters, cardiac and liver enzymes, C-reactive protein and procalcitonin were normal. Screening results for SARS-CoV-2 and extended respiratory virus panel were negative. Examinations using chest radiography, abdominal computed tomography, electrocardiography and focussed assessment with sonography for trauma echocardiography were unremarkable (Table 1 and Table 2). We started intravenous fluids and empiric treatment with piperacillin–tazobactam, despite the unlikelihood of an infectious process. Twelve hours later, the patient had received more than 6 L of fluid, but his blood pressure had deteriorated to 93/60 mm Hg, his heart rate was 125 beats/min and his polycythemia persisted (hemoglobin 223 g/L). We admitted the patient to the intensive care unit (ICU). In the absence of other causes of impending shock, we diagnosed systemic capillary leak syndrome (SCLS). Key points • Rare cases of systemic capillary leak syndrome (SCLS) have been reported worldwide afer vaccination with adenoviral vector and mRNA vaccines against SARS-CoV-2; a number have occurred in patients with a history of SCLS. • Systemic capillary leak syndrome is a potentially lifethreatening immune disorder that is characterized by transient, recurrent episodes of vascular endothelial hyperpermeability that are ofen triggered by viral upper respiratory infections. • Hypotension, hemoconcentration, hypoalbuminemia and anasarca are prominent features of SCLS, reflecting the massive leakage of fluids and proteins into peripheral tissues. • Acute SCLS can rapidly evolve into shock and multiorgan failure, and treatment is mostly aimed at correcting hypovolemia and avoiding end-organ damage; prophylactic monthly administration of immunoglobulins can help prevent further episodes. • Adenoviral vector vaccines against SARS-CoV-2 are not advised for patients with a history of SCLS.