Researchers from City Hospital, St. Petersburg-Russia, Military Medical Academy, Petersburg-Russia, and Saint-Petersburg State University-Russia have conducted a study exploring the impact of severe COVID-19 on red blood cell (RBC) morphology. Using Low-Voltage Scanning Electron Microscopy (LVSEM) images, the researchers compared RBC morphology between healthy donors and COVID-19 patients, potentially uncovering novel insights into the disease.
The study revealed several interesting findings. Among COVID-19 patients, there was a significant increase in the percentage of acanthocytes, which are RBCs associated with various health conditions. This suggests that the virus may exacerbate underlying health issues, impacting RBC morphology. Additionally, a decrease in the number of spherocytes, spherical RBCs commonly found in certain conditions, was observed in COVID-19 patients. This decrease may be due to heightened clearance by splenic and liver macrophages during the immune response.
The researchers also observed a significant increase in the size of erythrocytes among COVID-19 patients. This finding aligns with previous research on Red Cell Distribution Width (RDW) and disease severity. The exact mechanisms behind this phenomenon are still unclear, but it could be related to the virus’s impact on RBCs or the development of coagulopathy and microvascular thrombi.
One intriguing aspect of the research is the elevated caspase-3/7 levels in RBCs of COVID-19 patients. Caspases are enzymes involved in apoptosis, and their presence in RBCs suggests a potential role in erythropoiesis. It is hypothesized that immature forms of RBCs may enter the bloodstream due to the virus’s affinity for ACE2 receptors found on RBC precursors.
Overall, this groundbreaking research using LVSEM has provided crucial insights into the impact of severe COVID-19 on RBC morphology. The findings highlight that the effects of COVID-19 extend beyond the respiratory system, affecting even the smallest but essential components of our circulatory system – our red blood cells. Further investigations are needed to understand the mechanisms underlying these alterations and their potential implications for disease severity and patient outcomes.