In this case, renal artery thrombosis suddenly occurred during the treatment of COVID-19 and subsequently led to left renal threatening ischemia. The laboratory test indicating thrombotic complications was elevated D-dimer. Previous studies have shown that elevated D-dimer was a risk factor for death in patients with SARS-CoV-2 infection, especially in elderly patients [
7,
8]. The hypercoagulation status of COVID-19 and the subsequent series of vascular complications are a vital topic that is currently emerging [
9]. Previous reports have suggested that patients with renal artery thrombosis were patients with atrial fibrillation or had a history of renal artery stenting. Interestingly, the patient in this case had no history of atrial fibrillation or renal artery surgery, and the occurrence of renal artery thrombosis suggested that it was related to vascular damage and coagulation function changes in novel Coronavirus. This has implications for future renal injury complications from COVID-19 [
10‐
12]. The question of anticoagulant therapy at prophylaxis dose or even higher was subsequently raised [
13]. It has been suggested that immune-mediated reaction or direct viral infection of the endothelium will lead to recruitment of immune cells, which may develop into extensive endothelial dysfunction [
14]. Angiotensin converting enzyme 2 (ACE2) receptors are expressed in organs including lung, heart, kidney and intestine. Vascular endothelial cells also express angiotensin converting enzyme 2 receptor. And the virus can directly infect endothelial cells by converting enzyme 2 and cause diffuse endothelial inflammation [
15]. SARS-CoV-2 infection can develop into acute respiratory distress syndrome. Similar to other viral infections, early cytokine storms are caused by overproduction of response proinflammatory cytokines including tumor necrosis factor, interleukin-6 and interleukin-1 β, resulting in an increased risk of multiorgan failure and vascular hyperpermeability [
16]. The main function of thrombin in the immune response is to promote the formation of clots by activating platelets and converting fibrinogen to fibrin. However, it is worth noting that the cellular effect of thrombin, mainly par-1 (proteinase-activated receptors), can further enhance inflammation [
17]. Protein C system, tissue factor pathway inhibitor and antithrombin are defective during inflammation, which impairs the coagulant–anticoagulant balance and leads to the formation of microthrombus [
18]. The hypercoagulation status of blood caused by the infection of SARS-CoV-2 can lead to a variety of intravascular thrombotic phenomena, ranging from limited venous and arterial thrombosis to fatal disseminated intravascular coagulation.
Thrombotic events caused by hypercoagulation status secondary to vascular endothelial injury deserves our attention. Because timely anticoagulation can reduce the risk of early complications.