Red Blood Cell Malfunction in COVID-19: Molecular Mechanisms and Therapeutic Targets.

The world has been facing a pandemic for the past 2 years. COVID-19 still leads to millions of deaths worldwide, while deteriorating the global economy. The need for therapeutic targets, thus, remains. Interestingly, red blood cells, apart from gas exchange, also serve as modulators of innate and adaptive immunity. This function is accommodated mainly by surface molecules (proteins, lipids, and carbohydrates) and increased antioxidant capacity. However, under the circumstances of a disease state, red blood cells can become proinflammatory cells. Recent evidence has shown that, in the context of COVID-19, erythrocytes present protein oxidation, decreased antioxidant capacity, increased glycolysis, altered membrane lipidome, increased binding of Cytosine-Guanine (CpG) DNA and complement proteins, and low CD47 levels. These changes lead to an erythrocyte-dependent inflammation, which possibly participates in the hyperinflammation status of COVID-19. The current knowledge for the dysfunction of red blood cells during COVID-19 implies that the BAND3 protein and toll-like receptor 9 are potential therapeutic targets for COVID-19.

Giant Pulmonary Artery Thrombotic Material, Due to Chronic Thromboembolic Pulmonary Hypertension, Mimics Pulmonary Artery Sarcoma.

In this article, we present the case of a 38-year-old female who suffered from serious respiratory distress. After an extensive pulmonary artery imaging diagnostic work-up (CTPA, MRA and PET), we were unable to differentiate between chronic thromboembolic pulmonary hypertension (CTEPH) vs. pulmonary artery sarcoma (PAS) due to extensive filling defects and extraluminal findings. Although surgery was postponed for nine months due to the COVID-19 pandemic, CTEPH diagnosis, due to a high-thrombus burden, was finally confirmed after pulmonary endarterectomy (PEA). Conclusively, imaging findings of rare cases of CTEPH might mimic PAS and the surgical removal of the lesion are both needed for a final diagnosis. What is Already Known about This Topic? Pulmonary artery sarcoma (PAS) is a rare but aggressive malignancy, which originates from the intimal layer of the pulmonary artery (PA); Chronic thromboembolic pulmonary hypertension (CTEPH) is based on chronic, organized flow-limiting thrombi inside PA circulation and subsequent pulmonary hypertension. What Does This Study Contribute? Since radiological findings of CTEPH cases might rarely mimic PAS, pulmonary artery endarterectomy and subsequent histopathologic study are needed for a final diagnosis.