Red Blood Cell Abnormalities as the Mirror of SARS-CoV-2 Disease Severity: A Pilot Study

Universal new blood cell elution method with extensive phenotyping

BACKGROUND/OBJECTIVES

No erythrocyte elution method developed is uniformly successful or allows elution/phenotyping together. We previously developed an elution method using deionised formamide. We modified it to be universal for various cell types and call it modified formamide-method (Fm-method). It also preserves cells for phenotyping after elution.

MATERIALS AND METHODS

Fm-method reagent contains deionised formamide, buffered high salt, EDTA, TE. Elution-reagent is removed by column centrifugation. Blood samples were used for development and validation. Results compared to commercial/common antibody elution/phenotyping methods.

RESULTS

Fm-method eluted antibodies, complement, other proteins, and nucleic acids and works with erythrocytes, leukocytes, other cells. It worked better than commercial kits used for elution/phenotyping with no false positives/negatives. It did not denature Kell and Lewis antigens and could be repeated as needed on samples to recover more antibodies and clean cells for phenotyping. Western blotting, PAGE and FCM demonstrated eluted proteins were not degraded and cells remained intact.

CONCLUSION

Fm-method is excellent for elution and phenotyping and permits elution and phenotyping with one method and sample. It is useful for studies of various bound molecules and cell surface structures. It should be possible to elute various simple and complex carbohydrates as well. The Fm-method is efficient, inexpensive, scalable, uses common reagents. It should have excellent applications in various clinical, research, commercial settings.

COVID-19's Impact on Athletes: Reduced Cardiorespiratory Fitness after a SARS-CoV-2 Infection

OBJECTIVE

This study aimed to identify potential changes in cardiorespiratory fitness among athletes who had previously been infected with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2).

METHODS

In this prospective observational multicenter hybrid study (CoSmo-S), cardiopulmonary exercise testing on treadmills or bicycle ergometers involving 2314 athletes (39.6% female) was conducted. German federal squad members (59.6%) and non-squad athletes were included in the study. A total of 1170 (37.2% female) subjects were tested positive for SARS-CoV-2 via polymerase chain reaction from which we had pre-SARS-CoV-2 infection examinations available for 289 subjects. Mixed-effect models were employed to analyze, among others, the following dependent variables: power output at individual anaerobic threshold (PO IAT ·kg -1 ), maximal power output (PO max ·kg -1 ), measured V̇O 2max ·kg -1 , heart rate at individual anaerobic threshold (HR IAT ), and maximal heart rate (HR max ).

RESULTS

A SARS-CoV-2 infection was associated with a decrease in PO IAT ·kg -1 (-0.123 W·kg -1 , P < 0.001), PO max ·kg -1 (-0.099 W·kg -1 , P = 0.002), and measured V̇O 2max ·kg -1 (-1.70 mL·min -1 ·kg -1 , P = 0.050), and an increase in HR IAT (2.50 bpm, P = 0.008) and HR max (2.59 bpm, P < 0.001) within the first 60 d after SARS-CoV-2 infection. Using the pandemic onset in Germany as a longitudinal reference point, the healthy control group showed no change over time in these variables and an increase in PO max (+0.126 W·kg -1 , P = 0.039) during the first 60 d after the reference point. Subgroup analyses showed that both squad members and endurance athletes experienced greater decreases in cardiorespiratory fitness compared with non-squad members respectively athletes from explosive power sports.

CONCLUSIONS

A SARS-CoV-2 infection is associated with a decline in cardiorespiratory fitness in athletes for approximately 60 d. Potential factors contributing to this outcome seem to be cardiopulmonary and vascular alterations in consequence of SARS-CoV-2. A minor effect on cardiorespiratory fitness has training interruption due to acute symptoms and/or quarantine.

Assessing the impact of severe acute respiratory syndrome coronavirus 2 infection on hematological parameters

BACKGROUND

The current study is a retrospective study designed to evaluate changes in complete blood count and coagulation parameters in adult coronavirus disease 2019 (COVID-19) patients at a prominent Saudi tertiary center to predict disease severity and mortality.

METHODS

The cohort consisted of 74 800 adult patients divided into four groups based on a COVID-19 test and the patient's sex: 35 985 in the female negative COVID-19 group, 23 278 in the male negative COVID-19 group, 8846 in the female positive COVID-19 group and 6691 in the male positive COVID-19 group.

RESULTS

Patients with COVID-19 demonstrated decreased white blood cell counts and increased red blood cell counts. Also, COVID-19-positive participants exhibited more prolonged partial thromboplastin time and lower D-dimer levels than those of COVID-19-negative subjects (p<0.05). The study also revealed gender-dependent impacts on platelet counts, implying a possible relationship with the greater infection mortality rate in men than in women (p<0.001). In addition, the study found a link between changes in coagulation test results and death in COVID-19 patients (p<0.001). The evidence regarding the effects of COVID-19 on blood cell counts and coagulation, on the other hand, is conflicting, most likely due to variances in study populations and the timing of testing postinfection.

CONCLUSIONS

According to the findings, COVID-19-related alterations in blood cell count and clotting ability may be risk factors for death.

Insights into the baseline blood pH homeostasis at admission and the risk of in-hospital mortality in COVID-19 patients

Aim: A laboratory finding in critically ill COVID-19 patients is blood academia (pH <7.35). We investigated its cause in connection with the admission baseline blood pH homeostasis.Patients & methods: We retrospectively monitored the baseline blood pH homeostasis of 1215 COVID-19 patients who were admitted with pneumonia using data-driven knowledge. Two categories of patients were identified: non-survivors (107) and survivors (1108).Results: Non-survivors showed greater levels of lactate and lower blood pH, saturation, and partial pressure of oxygen than survivors. A bivariate Spearman's correlation matrix showed that the [HCO3-]/pCO2 and pCO2 of non-survivors exhibited an unmatched connection, but not in the survivor group. When comparing non-survivors to survivors, the dendrograms derived from the bivariate comparison matrix showed differences in gasometry parameters like blood pH, [HCO3-]/pCO2 ratio, anion gap and pO2.Conclusion: The little variations in the gasometry readings between survivors and non-survivors upon admission suggested abnormal changes in the complementary renal and respiratory systems that bring blood pH back to normal. In advanced COVID-19, modest blood acid-base imbalances could become blood acidemia if these compensatory strategies were overused. Data-driven monitoring of acid-base parameters may help predict abnormal blood pH and the advancement of metabolic acidemia before it is too late.

Association between dietary magnesium intake, inflammation, and neurodegeneration

BACKGROUND

Consistent evidence shows that magnesium (Mg) intake is associated with lower blood pressure (BP), and that lower BP is associated with improved cerebral health. However, recent findings indicate that the positive effect of dietary Mg intake on cerebral health is not mediated by a decrease in BP. As Mg's anti-inflammatory action is a plausible alternative mechanism, the objective of this study was to investigate the associations between Mg intake and inflammation to determine whether it mediates any neuroprotective effect.

METHODS

Participants from the UK Biobank (n = 5775, aged 40-73 years, 54.7% female) were assessed for dietary magnesium using an online food questionnaire, brain and white matter lesion (WML) volumes were segmented with FreeSurfer software, and inflammation markers including high-sensitivity C-reactive protein (hs-CRP), leukocyte, erythrocyte count, and Glycoprotein acetylation (GlycA) were measured using specific laboratory techniques such as immunoturbidimetry, automated cell counting, and nuclear magnetic resonance. Hierarchical linear regression models were performed to investigate the association between dietary Mg, and inflammatory markers and between dietary Mg, brain and WMLs volumes. Mediation analysis was performed to test a possible mediation role of inflammation on the association between dietary Mg and brain and WMLs volumes.

RESULTS

Higher dietary Mg intake was associated with lower inflammation: hs-CRP level (- 0.0497%; 95% confidence interval [CI] - 0.0497%,  - 0.0199%) leukocytes count (- 0.0015%; 95%CI - 0.00151%,  - 0.0011%), and GlycA (- 0.0519%; 95%CI - 0.1298%,  - 0.0129%). Moreover, higher dietary Mg intake was associated with larger grey matter volume (0.010%; 95%CI 0.004%, 0.017%), white matter volume (0.012%; 95%CI 0.003,  0.022) and right hippocampal volume (0.002%; 95%CI 0.0007, -0.0025%). Lower hs-CRP levels mediated the positive association between higher dietary Mg intake and larger grey matter volume.

CONCLUSIONS

The anti-inflammatory effects of dietary Mg intake in the general population, appears to mediate its neuroprotective effect.

Modulation in serum and hematological parameters as a prognostic indicator of COVID-19 infection in hypertension, diabetes mellitus, and different cardiovascular diseases

SARS-CoV-2 infection affects and modulates serum as well as hematological parameters. However, whether it modifies these parameters in the existing disease conditions, which help in the erection of specific treatments for the disease, is under investigation. Here, we aimed to determine whether serum and hematological parameters alteration in various diseases, diabetes mellitus (DM), hypertension (HTN), ischemic heart disease (IHD) and myocardial infarction (MI) conditions correlate and signal SARS-CoV-2 infection, which could be used as a rapid diagnosis tool for SARS-CoV-2 infection in disease conditions. To assess the projected goals, we collected blood samples of 1,113 male and female patients with solo and multiple disease conditions of DM/HTN/IHD/MI with severe COVID-19, followed by biochemical analysis, including COVID-19 virus detection by RT-qPCR. Furthermore, blood was collected from age-matched disease and healthy individuals 502 and 660 and considered as negative control. In our results, we examined higher levels of serum parameters, including D-dimer, ferritin, hs-CRP, and LDH, as well as hematological parameters, including TLC in sole and multiple diseases (DM/HTN/IHD/MI) conditions compared to the control subjects. Besides, the hematological parameters, including Hb, RBC, and platelet levels, decreased in the patients. In addition, we found declined levels of leukocyte count (%), lymphocyte (%), monocyte (%), and eosinophil (%), and elevated level of neutrophil levels (%) in all the disease patients infected with SARS-CoV-2. Besides, NLR and NMR ratios were also statistically significantly (p < 0.05) high in the patients with solo and multiple disease conditions of DM/HTN/IHD/MI infected with the SARS-CoV-2 virus. In conclusion, rapid alteration of sera and hematological parameters are associated with SARS-CoV-2 infections, which could help signal COVID-19 in respective disease patients. Moreover, our results may help to improve the clinical management for the rapid diagnosis of COVID-19 concurrent with respective diseases.

Regulation of kynurenine metabolism by blood donor genetics and biology impacts red cell hemolysis in vitro and in vivo

ABSTRACT

In the field of transfusion medicine, the clinical relevance of the metabolic markers of the red blood cell (RBC) storage lesion is incompletely understood. Here, we performed metabolomics of RBC units from 643 donors enrolled in the Recipient Epidemiology and Donor Evaluation Study, REDS RBC Omics. These units were tested on storage days 10, 23, and 42 for a total of 1929 samples and also characterized for end-of-storage hemolytic propensity after oxidative and osmotic insults. Our results indicate that the metabolic markers of the storage lesion poorly correlated with hemolytic propensity. In contrast, kynurenine was not affected by storage duration and was identified as the top predictor of osmotic fragility. RBC kynurenine levels were affected by donor age and body mass index and were reproducible within the same donor across multiple donations from 2 to 12 months apart. To delve into the genetic underpinnings of kynurenine levels in stored RBCs, we thus tested kynurenine levels in stored RBCs on day 42 from 13 091 donors from the REDS RBC Omics study, a population that was also genotyped for 879 000 single nucleotide polymorphisms. Through a metabolite quantitative trait loci analysis, we identified polymorphisms in SLC7A5, ATXN2, and a series of rate-limiting enzymes (eg, kynurenine monooxygenase, indoleamine 2,3-dioxygenase, and tryptophan dioxygenase) in the kynurenine pathway as critical factors affecting RBC kynurenine levels. By interrogating a donor-recipient linkage vein-to-vein database, we then report that SLC7A5 polymorphisms are also associated with changes in hemoglobin and bilirubin levels, suggestive of in vivo hemolysis in 4470 individuals who were critically ill and receiving single-unit transfusions.

Morphological abnormalities of peripheral blood cells among patients with COVID-19 disease

Purpose

The hematological changes in COVID-19 patients continue to receive great attention, especially in the field of public health. To our knowledge, coronavirus disease may be identified based on the severity of illness, and the study of peripheral blood smears may offer important information to facilitate the identification. Thus, we evaluated the morphological abnormalities (atypical and immature lymphocytes, lymphocytes with micronuclei, various nuclear abnormalities among erythrocytes) and quantitative changes in peripheral blood cells among 48 individuals with COVID-19 disease.

Methods

The present study is a retrospective analysis of 48 individuals, including 24 hospitalized patients diagnosed with COVID-19 disease. The blood smears of all patients were subjected to a hematological examination to identify various morphological abnormalities in white and red blood cells. In addition, a micronucleus test was conducted to assess the incidence of chromosomal damage in lymphocytes. Furthermore, the complete blood count (CBC) was performed to evaluate changes in peripheral blood cells, particularly the differential total leukocyte count, which could indicate the immune response against viral infection in COVID-19 patients.

Results

The findings of the hematological study conducted on patients diagnosed with COVID-19 disease revealed neutrophilia, eosinophilia, mild monocytosis, decreased hematocrit level, elevated erythrocyte sedimentation rate (ESR), and immature leukocytes. It was observed that patients who were infected with coronavirus demonstrated mild thrombocytopenia. Furthermore, the micronucleus test indicated the presence of immature cells with micronuclei among lymphocytes and numerous nuclear abnormalities in red blood cells. These results help to shed light on the hematological changes that occur in COVID-19 patients, and could potentially contribute to the development of more effective treatments for the disease.

Conclusions

The examination of complete blood counts (CBCs) in conjunction with peripheral blood smears offers a potential means of identifying the impact of SARS-CoV-2 infection on the hematopoietic and immune systems, thereby providing early indications of inflammation. Based on a study, it has been suggested that SARS-CoV-2 may affect red and white blood cells causing morphological alterations thereby establishing a corresponding relationship with disease severity.

Effect of silica-based mesoporous nanomaterials on human blood cells

Different mesoporous nanomaterials (MSNs) are constantly being developed for a range of therapeutic purposes, but they invariably interact with blood components and may cause hazardous side effects. Therefore, when designing and developing nanoparticles for biomedical applications, hemocompatibility should be one of the primary goals to assess their toxicity at the cellular level of all blood components. The aim of this study was to evaluate the compatibility of human blood cells (erythrocytes, platelets, and leukocytes) after exposure to silica-based mesoporous nanomaterials that had been manufactured using the sol-gel method, with Ca and Ce as doping elements. The viability of lymphocytes and monocytes was unaffected by the presence of MSNs at any concentration. However, it was found that all nanomaterials, at all concentrations, reduced the viability of granulocytes. P-selectin expression of all MSNs at all concentrations was statistically significantly higher in platelet incubation on the first day of storage (day 1) compared to the control. When incubated with MSNs, preserved platelets displayed higher levels of iROS at all MSNs types and concentrations examined. Ce-containing MSNs presented a slightly better hemocompatibility, although it was also dose dependent. Further research is required to determine how the unique characteristics of MSNs may affect various blood components in order to design safe and effective MSNs for various biomedical applications.

COVID-19 impairs oxygen delivery by altering red blood cell hematological, hemorheological, and oxygen transport properties

Introduction: Coronavirus disease 2019 (COVID-19) is characterized by impaired oxygen (O2) homeostasis, including O2 sensing, uptake, transport/delivery, and consumption. Red blood cells (RBCs) are central to maintaining O2 homeostasis and undergo direct exposure to coronavirus in vivo. We thus hypothesized that COVID-19 alters RBC properties relevant to O2 homeostasis, including the hematological profile, Hb O2 transport characteristics, rheology, and the hypoxic vasodilatory (HVD) reflex. Methods: RBCs from 18 hospitalized COVID-19 subjects and 20 healthy controls were analyzed as follows: (i) clinical hematological parameters (complete blood count; hematology analyzer); (ii) O2 dissociation curves (p50, Hill number, and Bohr plot; Hemox-Analyzer); (iii) rheological properties (osmotic fragility, deformability, and aggregation; laser-assisted optical rotational cell analyzer (LORRCA) ektacytometry); and (iv) vasoactivity (the RBC HVD; vascular ring bioassay). Results: Compared to age- and gender-matched healthy controls, COVID-19 subjects demonstrated 1) significant hematological differences (increased WBC count-with a higher percentage of neutrophils); RBC distribution width (RDW); and reduced hematocrit (HCT), Hb concentration, mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC); 2) impaired O2-carrying capacity and O2 capacitance (resulting from anemia) without difference in p50 or Hb-O2 cooperativity; 3) compromised regulation of RBC volume (altered osmotic fragility); 4) reduced RBC deformability; 5) accelerated RBC aggregation kinetics; and (6) no change in the RBC HVD reflex. Discussion: When considered collectively, homeostatic compensation for these RBC impairments requires that the cardiac output in the COVID cohort would need to increase by ∼135% to maintain O2 delivery similar to that in the control cohort. Additionally, the COVID-19 disease RBC properties were found to be exaggerated in blood-type O hospitalized COVID-19 subjects compared to blood-type A. These data indicate that altered RBC features in hospitalized COVID-19 subjects burden the cardiovascular system to maintain O2 delivery homeostasis, which appears exaggerated by blood type (more pronounced with blood-type O) and likely plays a role in disease pathogenesis.

Persistence of circulating CD169+monocytes and HLA-DR downregulation underline the immune response impairment in PASC individuals: the potential contribution of different COVID-19 pandemic waves

The use of CD169 as a marker of viral infection has been widely discussed in the context of COVID-19, and in particular, its crucial role in the early detection of SARS-CoV-2 infection and its association with the severity and clinical outcome of COVID-19 were demonstrated. COVID-19 patients show relevant systemic alteration and immunological dysfunction that persists in individuals with post-acute sequelae of SARS-CoV-2 infection (PASC). It is critical to implement the characterization of the disease, focusing also on the possible impact of the different COVID-19 waves and the consequent effects found after infection. On this basis, we evaluated by flow cytometry the expression of CD169 and HLA-DR on monocytes from COVID-19 patients and PASC individuals to better elucidate their involvement in immunological dysfunction, also evaluating the possible impact of different pandemic waves. The results confirm CD169 RMFI is a good marker of viral infection. Moreover, COVID-19 patients and PASC individuals showed high percentage of CD169+ monocytes, but low percentage of HLA-DR+ monocytes and the alteration of systemic inflammatory indices. We have also observed alterations of CD169 and HLA-DR expression and indices of inflammation upon different COVID-19 waves. The persistence of specific myeloid subpopulations suggests a role of CD169+ monocytes and HLA-DR in COVID-19 disease and chronic post-infection inflammation, opening new opportunities to evaluate the impact of specific pandemic waves on the immune response impairment and systemic alterations with the perspective to provide new tools to monitoring new variants and diseases associated to emerging respiratory viruses.

The Ways of the Virus: Interactions of Platelets and Red Blood Cells with SARS-CoV-2, and Their Potential Pathophysiological Significance in COVID-19

The hematological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important in COVID-19 pathophysiology. However, the interactions of SARS-CoV-2 with platelets and red blood cells are still poorly understood. There are conflicting data regarding the mechanisms and significance of these interactions. The aim of this review is to put together available data and discuss hypotheses, the known and suspected effects of the virus on these blood cells, their pathophysiological and diagnostic significance, and the potential role of platelets and red blood cells in the virus's transport, propagation, and clearance by the immune system. We pay particular attention to the mutual activation of platelets, the immune system, the endothelium, and blood coagulation and how this changes with the evolution of SARS-CoV-2. There is now convincing evidence that platelets, along with platelet and erythroid precursors (but not mature erythrocytes), are frequently infected by SARS-CoV-2 and functionally changed. The mechanisms of infection of these cells and their role are not yet entirely clear. Still, the changes in platelets and red blood cells in COVID-19 are significantly associated with disease severity and are likely to have prognostic and pathophysiological significance in the development of thrombotic and pulmonary complications.

SARS-CoV-2 Impact on Red Blood Cell Morphology

Severe COVID-19 alters the biochemical and morphological characteristics of blood cells in a wide variety of ways. To date, however, the vast majority of research has been devoted to the study of leukocytes, while erythrocyte morphological changes have received significantly less attention. The aim of this research was to identify erythrocyte morphology abnormalities that occur in COVID-19, compare the number of different poikilocyte types, and measure erythrocyte sizes to provide data on size dispersion. Red blood cells obtained from 6 control donors (800-2200 cells per donor) and 5 COVID-19 patients (800-1900 cells per patient) were examined using low-voltage scanning electron microscopy. We did not discover any forms of erythrocyte morphology abnormalities that would be specific to COVID-19. Among COVID-19 patients, we observed an increase in the number of acanthocytes (p = 0.01) and a decrease in the number of spherocytes (p = 0.03). In addition, our research demonstrates that COVID-19 causes an increase in the median (p = 0.004) and interquartile range (p = 0.009) when assessing erythrocyte size. The limitation of our study is a small number of participants.

Comparison of Hematological Parameters Between Survivors and Non-Survivors COVID-19 Patients in Saudi Arabia

Objective

Coronavirus disease 2019, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a communicable disease transmitted through the respiratory route and bodily contact. The severity of infection and mortality rate of COVID-19 cases was significantly high in the initial stages of the pandemic. This study aims to investigate the hematological profile of COVID-19 survivors and non-survivors.

Methods

This is a single-center retrospective study. A total of 108 hospitalized patients with laboratory-confirmed COVID-19 at East Jeddah Hospital between April and August 2020 were categorized into two groups based on outcome as survivors (n = 54) and non-survivors (n = 54). Hematological parameters and clinical profiles were analyzed and compared between the two groups.

Results

The mean age and standard deviation of the survived (30-71 years) and non-survived (33-83) groups was 53 ± 10.8 and 57.9 ± 12.2 years, respectively, with no statistically significant difference in age between groups (p = 0.0513). Non-survivors had a significantly longer median length of stay in the intensive care unit (ICU) (7 days, IQR: 4.24 to 12) compared to survivors COVID-19 patients (5 days, IQR: 0 to 11.75) (p = 0.0151). For the survivors group, the participant's age positively correlated with the length of hospital stay (r(52) = 0.21, p = 0.0005) and ICU length of stay r(52) = 0.18, p = 0.001). The median red blood cells (RBC) counts were significantly higher in the survived group (4.56x109/L, IQR: 4.02 to 5.11) in comparison with the non-survived (4.23x109/L, IQR: 3.75 to 4.23) group (p = 0.0011). All COVID-19 patients exhibited lymphocytopenia and a significant negative correlation was observed between the lymphocyte values and length of hospital stay among the survived group (p < 0.001) as well as length of ICU stay among the survived group (p < 0.0480). Disease-related mortality was significantly associated with reduced white blood cells (WBCs) (8.5×109/L, IQR: 6.1 to 11.7) and reduced basophils (0.09%, IQR: 0.02 to 0.19). Additionally, statistically significant differences were found between the survived and non-survived groups with respect to prothrombin time (PT) (12.5 sec. vs 14 sec., p < 0.0001) and partial thromboplastin time (PTT) (31.8 sec. vs 40 sec., p = 0.0008).

Conclusion

Hematological parameters can serve as valuable indicators to identify patients with severe COVID-19 and expected poor-prognosis/outcomes upon hospital admission. Cell counts of lymphocytes, WBCs, basophils and parameters such as PT and PTT can serve as clinical indicators to assess disease severity and predict progression to critical illness.

Toll-like Receptors as Pro-Thrombotic Drivers in Viral Infections: A Narrative Review

Toll-like receptors (TLRs) have a critical role in the pathogenesis and disease course of viral infections. The induced pro-inflammatory responses result in the disturbance of the endovascular surface layer and impair vascular homeostasis. The injury of the vessel wall further promotes pro-thrombotic and pro-coagulatory processes, eventually leading to micro-vessel plugging and tissue necrosis. Moreover, TLRs have a direct role in the sensing of viruses and platelet activation. TLR-mediated upregulation of von Willebrand factor release and neutrophil, as well as macrophage extra-cellular trap formation, further contribute to (micro-) thrombotic processes during inflammation. The following review focuses on TLR signaling pathways of TLRs expressed in humans provoking pro-thrombotic responses, which determine patient outcome during viral infections, especially in those with cardiovascular diseases.

Nutrients, herbal bioactive derivatives and commensal microbiota as tools to lower the risk of SARS-CoV-2 infection

The SARS-CoV-2 outbreak has infected a vast population across the world, causing more than 664 million cases and 6.7 million deaths by January 2023. Vaccination has been effective in reducing the most critical aftermath of this infection, but some issues are still present regarding re-infection prevention, effectiveness against variants, vaccine hesitancy and worldwide accessibility. Moreover, although several old and new antiviral drugs have been tested, we still lack robust and specific treatment modalities. It appears of utmost importance, facing this continuously growing pandemic, to focus on alternative practices grounded on firm scientific bases. In this article, we aim to outline a rigorous scientific background and propose complementary nutritional tools useful toward containment, and ultimately control, of SARS-CoV-2 infection. In particular, we review the mechanisms of viral entry and discuss the role of polyunsaturated fatty acids derived from α-linolenic acid and other nutrients in preventing the interaction of SARS-CoV-2 with its entry gateways. In a similar way, we analyze in detail the role of herbal-derived pharmacological compounds and specific microbial strains or microbial-derived polypeptides in the prevention of SARS-CoV-2 entry. In addition, we highlight the role of probiotics, nutrients and herbal-derived compounds in stimulating the immunity response.

SARS-CoV-2 Altered Hemorheological and Hematological Parameters during One-Month Observation Period in Critically Ill COVID-19 Patients

Hematological and hemorheological parameters are known to be altered in COVID-19; however, the value of combined monitoring in order to deduce disease severity is only scarcely examined. A total of 44 acute SARS-CoV-2-infected patients (aCOV) and 44 age-matched healthy controls (Con) were included. Blood of aCOV was sampled at admission (T0), and at day 2 (T2), day 5 (T5), day 10 (T10), and day 30 (T30) while blood of Con was only sampled once. Inter- and intra-group differences were calculated for hematological and hemorheological parameters. Except for mean cellular volume and mean cellular hemoglobin, all blood cell parameters were significantly different between aCOV and Con. During the acute disease state (T0-T5), hematological and hemorheological parameters were highly altered in aCOV; in particular, anemic conditions and increased immune cell response/inflammation, oxidative/nitrosative stress, decreased deformability, as well as increased aggregation, were observed. During treatment and convalescence until T30, almost all abnormal values of aCOV improved towards Con values. During the acute state of the COVID-19 disease, the hematological, as well as the hemorheological system, show fast and potentially pathological changes that might contribute to the progression of the disease, but changes appear to be largely reversible after four weeks. Measuring RBC deformability and aggregation, as well as oxidative stress induction, may be helpful in monitoring critically ill COVID-19 patients.

Cardiopulmonary Injury in the Syrian Hamster Model of COVID-19

The Syrian hamster has proved useful in the evaluation of therapeutics and vaccines for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). To advance the model for preclinical studies, we conducted serial sacrifice of lungs, large pulmonary vessels, and hearts from male and female Syrian hamsters for days 1–4, and 8 post-infection (dpi) following infection with a high dose of SARS-CoV-2. Evaluation of microscopic lung histopathology scores suggests 4 and 8 dpi as prime indicators in the evaluation of moderate pathology with bronchial hyperplasia, alveolar involvement and bronchiolization being key assessments of lung disease and recovery, respectively. In addition, neutrophil levels, red blood cell count and hematocrit showed significant increases during early infection. We present histological evidence of severe damage to the pulmonary vasculature with extensive leukocyte transmigration and the loss of endothelial cells and tunica media. Our evidence of endothelial and inflammatory cell death in the pulmonary vessels suggests endothelialitis secondary to SARS-CoV-2 epithelial cell infection as a possible determinant of the pathological findings along with the host inflammatory response. Lastly, pathological examination of the heart revealed evidence for intracardiac platelet/fibrin aggregates in male and female hamsters on 8 dpi, which might be indicative of a hypercoagulative state in these animals.

Pathophysiological Changes in Erythrocytes Contributing to Complications of Inflammation and Coagulation in COVID-19

Higher thrombotic burden in the acute phase of COVID-19 relies on a complex interplay between pro-inflammatory cytokine/chemokine release, increased endothelial dysfunction/damage, and potential sepsis-induced coagulopathy development in severe cases, all promoting coagulation activation. Plasma levels of cytokines and chemokines are known to be increased in COVID-19 however, are much higher in severe infections. Increased levels of IL-1β, IL-6, and IL-8 are known to play an important role in both acute and chronic inflammation, resulting in pathological clotting. However, little has been published on the effects of these interleukins on red blood cells (RBCs). Evidence shows that cytokines have a negative effect on the RBCs ultrastructure and introduce signs of eryptosis. Eryptosis can be described as a form of suicidal death of RBCs characterized by distinct findings of cell shrinkage, membrane blebbing, activation of proteases, and phosphatidylserine exposure at the outer membrane leaflet. Red blood cells from COVID-19 patients had increased levels of glycolytic intermediates, accompanied by oxidation and fragmentation of ankyrin, spectrin beta, and the N-terminal cytosolic domain of band 3 (AE1). Significantly altered lipid metabolism was also observed, in particular, short- and medium-chain saturated fatty acids, acyl-carnitines, and sphingolipids. Emerging research suggests that RBCs may contribute to a precision medicine approach to sepsis and have diagnostic value in monitoring complement dysregulation in COVID-19-sepsis and non-COVID sepsis as research indicates that complement activation products and viral antigens are present on RBCs in patients with COVID-19.

The AIFELL Score as a Predictor of Coronavirus Disease 2019 (COVID-19) Severity and Progression in Hospitalized Patients

Since the beginning of the COVID-19 pandemic, SARS-CoV-2 has caused a global burden for health care systems due to high morbidity and mortality rates, leading to caseloads that episodically surpass hospital resources. Due to different disease manifestations, the triage of patients at high risk for a poor outcome continues to be a major challenge for clinicians. The AIFELL score was developed as a simple decision instrument for emergency rooms to distinguish COVID-19 patients in severe disease stages from less severe COVID-19 and non-COVID-19 cases. In the present study, we aimed to evaluate the AIFELL score as a prediction tool for clinical deterioration and disease severity in hospitalized COVID-19 patients. During the second wave of the COVID-19 pandemic in Switzerland, we analyzed consecutively hospitalized patients at the Triemli Hospital Zurich from the end of November 2020 until mid-February 2021. Statistical analyses were performed for group comparisons and to evaluate significance. AIFELL scores of patients developing severe COVID-19 stages IIb and III during hospitalization were significantly higher upon admission compared to those patients not surpassing stages I and IIa. Group comparisons indicated significantly different AIFELL scores between each stage. In conclusion, the AIFELL score at admission was useful to predict the disease severity and progression in hospitalized COVID-19 patients.