“…Similar results were published by Sweeney et al ( 29 ) who observed many schistocytes (fragments of erythrocytes) in blood smears. Gerard et al ( 30 ) described abnormal red cell morphology especially “mushroom-shaped erythrocytes.” In addition, red cells with damaged membranes (fragmentocytes; Fig. 1 ) have been detected.…”
Section: Intraerythrocytic Changes In Covid-19mentioning
COVID-19 hinders oxygen transport to the consuming tissues by at least 2 mechanisms: In the injured lung saturation of hemoglobin is compromised, in the tissues an associated anemia reduces the volume of delivered oxygen. For the first problem increased hemoglobin oxygen affinity (left shift of the oxygen dissociation curve ODC) is of advantage, for the 2nd, however, the contrary is the case. Indeed a right shift of the ODC has been found in former studies for anemia caused by reduced cell production or hemolysis. This resulted from increased 2,3-biphosphglycerate (2,3-BPG) concentration. In 3 investigations in COVID-19, however, no change of hemoglobin affinity was detected in spite of probably high [2,3-BPG]. The most plausible cause for this finding is formation of methemoglobin, which increases the oxygen affinity and thus apparently compensates for the 2,3-BPG effect. But this "useful effect" is cancelled by the concomitant reduction of functional hemoglobin. In the largest study on COVID-19 even a clear left shift of the ODC was detected when calculated from measurements in fresh blood rather than after equilibration with gases outside the body. This additional „in vivo" left shift possibly results from various factors (e. g. concentration changes of Cl-, 2,3-BPG, ATP, lactate, nitrocompounds, glutathione, glutamate, because of time delay between blood sampling and end of equilibration, or enlarged distribution space including interstitial fluid and is useful for O2 uptake in the lungs. Under discussion for therapy are the affinity-increasing 5-hydroxymethyl-2-furfural (5-HMF), erythropoiesis stimulating substances like erythropoietin, and methylene blue against MetHb formation.
“…Similar results were published by Sweeney et al ( 29 ) who observed many schistocytes (fragments of erythrocytes) in blood smears. Gerard et al ( 30 ) described abnormal red cell morphology especially “mushroom-shaped erythrocytes.” In addition, red cells with damaged membranes (fragmentocytes; Fig. 1 ) have been detected.…”
Section: Intraerythrocytic Changes In Covid-19mentioning
COVID-19 hinders oxygen transport to the consuming tissues by at least 2 mechanisms: In the injured lung saturation of hemoglobin is compromised, in the tissues an associated anemia reduces the volume of delivered oxygen. For the first problem increased hemoglobin oxygen affinity (left shift of the oxygen dissociation curve ODC) is of advantage, for the 2nd, however, the contrary is the case. Indeed a right shift of the ODC has been found in former studies for anemia caused by reduced cell production or hemolysis. This resulted from increased 2,3-biphosphglycerate (2,3-BPG) concentration. In 3 investigations in COVID-19, however, no change of hemoglobin affinity was detected in spite of probably high [2,3-BPG]. The most plausible cause for this finding is formation of methemoglobin, which increases the oxygen affinity and thus apparently compensates for the 2,3-BPG effect. But this "useful effect" is cancelled by the concomitant reduction of functional hemoglobin. In the largest study on COVID-19 even a clear left shift of the ODC was detected when calculated from measurements in fresh blood rather than after equilibration with gases outside the body. This additional „in vivo" left shift possibly results from various factors (e. g. concentration changes of Cl-, 2,3-BPG, ATP, lactate, nitrocompounds, glutathione, glutamate, because of time delay between blood sampling and end of equilibration, or enlarged distribution space including interstitial fluid and is useful for O2 uptake in the lungs. Under discussion for therapy are the affinity-increasing 5-hydroxymethyl-2-furfural (5-HMF), erythropoiesis stimulating substances like erythropoietin, and methylene blue against MetHb formation.
“…According to Delphine Gérard and collaborators, patients with COVID-19 present mushroom cells and abnormal red cell morphology, with the presence of anisocytosis, spherocytosis, stomatocytes and polychromasia ( 32 ). These changes in the erythrocyte morphophysiology may be related to the imbalanced redox status found in infectious and inflammatory situations, as seen during COVID-19 ( 33 , 34 , 35 ), which promotes oxidative stress in tissues by: i) elevating the levels of free circulating radicals, including reactive oxygen species (ROS), and; ii) reducing the antioxidative enzymatic mechanisms, especially superoxide dismutase (SOD) and catalase (CAT).…”
Section: Hematological Implications Of Sars-cov-2 Infection: Pathophysiological Erythrocytic Protagonismmentioning
confidence: 99%
“…These changes in the erythrocyte morphophysiology may be related to the imbalanced redox status found in infectious and inflammatory situations, as seen during COVID-19 ( 33 , 34 , 35 ), which promotes oxidative stress in tissues by: i) elevating the levels of free circulating radicals, including reactive oxygen species (ROS), and; ii) reducing the antioxidative enzymatic mechanisms, especially superoxide dismutase (SOD) and catalase (CAT). During metabolic processes, these free radicals mediate various biochemical reactions, including electron transfer for energy generation, activation of genes and defense mechanisms during the infection process ( 32 , 33 , 34 , 35 , 36 , 37 ). However, oxidative damage is often associated either with the overproduction of free radicals and ROS, that attack important structures inside the cells, or with the downregulation in the antioxidant systems ( 37 ).…”
Section: Hematological Implications Of Sars-cov-2 Infection: Pathophysiological Erythrocytic Protagonismmentioning
confidence: 99%
“…In addition to the changes in the red blood cell integrity, iron, and redox status, COVID-19 may be associated with a deficiency of the Band-3 protein prior to the appearance of mushroom erythrocytes and clamp cells, as well as Heinz bodies, that are intra-erythrocytic inclusions resulting from globin chains precipitation following hemoglobin oxidation, likely detected in cytopathological tests in COVID-19 patients. These bizarre erythrocytes can also be seen in bone marrow myelofibrosis and, occasionally, in nonspecific dyseritropoiesis ( 32 , 66 ). The following figure ( Fig.…”
Section: Hematological Implications Of Sars-cov-2 Infection: Pathophysiological Erythrocytic Protagonismmentioning
Introduction
:
The evolving COVID-19 pandemic became a hallmark in human history, not only by changing lifestyles, but also by enriching scientific knowledge on viral infection and its consequences.
Objective
:
Although management of cardiorespiratory changes is pivotal to a favorable prognosis during severe clinical findings, dysregulation of other systems caused by SARS-CoV-2 infection may imbalance erythrocyte dynamics, such as a bidirectional positive feedback loop pathophysiology.
Method and Results
:
Recent evidence shows that SARS-CoV-2 is capable of affecting the genetics and dynamics of erythrocytes and this coexists with a non-homeostatic function of cardiovascular, respiratory and renal systems during COVID-19. In hypothesis, SARS-CoV-2-induced systematical alterations of erythrocytes dynamics would constitute a setpoint for COVID-19-related multiple organ failure syndrome and death.
Conclusion
:
The present review covers the most frequent erythrocyte-related non-homeostatic findings during COVID-19 capable of providing mechanistic clues of SARS-CoV-2-induced infection and inspiring therapeutic-oriented scientific evidence.
“…However, a recent study have demonstrated a relationship between these cells and infection caused by Sars-CoV-2 in a pathophysiologic mechanism that possibly involves the occurrence of oxidative stress, which triggers progressive cascade of inflammation, known as citokines storm, that leads to red blood cell damage. 1 , 2 , 3 Figure 1 Pincer cells in a patient with chronic kidney disease and diagnosed with COVID-19. Figure 2 Pincer cells in a patient with chronic kidney disease and diagnosed with COVID-19.…”
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