Silent hypoxia: higher NO in red blood cells of COVID-19 patients

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.

Inhaled nitric oxide: can it serve as a savior for COVID-19 and related respiratory and cardiovascular diseases?

Nitric oxide (NO), as an important gaseous medium, plays a pivotal role in the human body, such as maintaining vascular homeostasis, regulating immune-inflammatory responses, inhibiting platelet aggregation, and inhibiting leukocyte adhesion. In recent years, the rapid prevalence of coronavirus disease 2019 (COVID-19) has greatly affected the daily lives and physical and mental health of people all over the world, and the therapeutic efficacy and resuscitation strategies for critically ill patients need to be further improved and perfected. Inhaled nitric oxide (iNO) is a selective pulmonary vasodilator, and some studies have demonstrated its potential therapeutic use for COVID-19, severe respiratory distress syndrome, pulmonary infections, and pulmonary hypertension. In this article, we describe the biochemistry and basic characteristics of NO and discuss whether iNO can act as a "savior" for COVID-19 and related respiratory and cardiovascular disorders to exert a potent clinical protective effect.

Clinicopathologic Analysis of COVID‐19 Associated Thrombi in the Setting of Large Vessel Occlusion: A Prospective Case–Control Study

BACKGROUND

Acute ischemic stroke secondary to large vessel occlusion is among the most serious complications associated with COVID‐19 infection resulting in worse morbidity and mortality. We sought to study the association between COVID‐19 infection and large vessel occlusion thrombus pathology to better define the etiopathogenesis of this atypical cause of stroke.

METHODS

Thrombi were collected during mechanical thrombectomy and stained using hematoxylin and eosin. Blinded analysis of pathology was prospectively performed by a board‐certified neuropathologist. Red blood cell, fibrin, and white blood cell predominance was ascertained. Concomitant peripheral blood counts and clinical and imaging data were collected and analyzed. All samples underwent performance of reverse transcription polymerase chain reaction for SARS‐CoV2.

RESULTS

Between January 2020 and February 2022, a total of 952 acute ischemic stroke admissions were seen at the University Medical Center of El Paso, TX. Of these, 195 patients (20.5%) had large vessel occlusions and underwent mechanical thrombectomy and 53 patients had thrombus collected and analyzed. Seven patients (3.6%) tested positive for SARS‐CoV2. COVID‐19 positive patients were more likely to be younger (mean 57.4 years; P =0.07), male (85.7%; P =0.03), and have red blood cell predominant thrombi (85.7%; P =0.03). There was a statistically significant association between peripheral neutrophil count and white blood cell lysis in the overall cohort ( P =0.015), who did not differ according to COVID‐19 status.

CONCLUSION

Thrombi retrieved from patients who were COVID‐19 positive and had stroke demonstrated red blood cell predominance. This finding requires further investigation using appropriate immunohistochemical techniques in a larger cohort of patients.

Nitric oxide mediated hypoxia dynamics in COVID-19

Several COVID-19 patients frequently experience with happy hypoxia. Sometimes, the level of nitric oxide (NO) in COVID-19 patients was found to be greater than in non-COVID-19 hypoxemics and most of the cases lower. Induced or inhaled NO has a long history of usage as a therapy for hypoxemia. Excessive production of ROS and oxidative stress lower the NO level and stimulates mitochondrial malfunction is the primary cause of hypoxia-mediated mortality in COVID-19. Higher level of NO in mitochondria also the cause of dysfunction, because, excess NO can also diffuse quickly into mitochondria or through mitochondrial nitric oxide synthase (NOS). A precise dose of NO may increase oxygenation while also acting as an effective inhibitor of cytokine storm. NOS inhibitors may be used in conjunction with iNO therapy to compensate for the patient's optimal NO level. NO play a key role in COVID-19 happy hypoxia and a crucial component in the COVID-19 pathogenesis that demands a reliable and easily accessible biomarker to monitor.

Dual role of nitric oxide in Alzheimer's Disease

Nitric oxide (NO), an enzymatic product of nitric oxide synthase (NOS), has been associated with a variety of neurological diseases such as Alzheimer's disease (AD). NO has long been thought to contribute to neurotoxic insults caused by neuroinflammation in AD. This perception shifts as more attention is paid to the early stages before cognitive problems manifest. However, it has revealed a compensatory neuroprotective role for NO that protects synapses by increasing neuronal excitability. NO can positively affect neurons by inducing neuroplasticity, neuroprotection, and myelination, as well as having cytolytic activity to reduce inflammation. NO can also induce long-term potentiation (LTP), a process by which synaptic connections among neurons become more potent. Not to mention that such functions give rise to AD protection. Notably, it is unquestionably necessary to conduct more research to clarify NO pathways in neurodegenerative dementias because doing so could help us better understand their pathophysiology and develop more effective treatment options. All these findings bring us to the prevailing notion that NO can be used either as a therapeutic agent in patients afflicted with AD and other memory impairment disorders or as a contributor to the neurotoxic and aggressive factor in AD. In this review, after presenting a general background on AD and NO, various factors that have a pivotal role in both protecting and exacerbating AD and their correlation with NO will be elucidated. Following this, both the neuroprotective and neurotoxic effects of NO on neurons and glial cells among AD cases will be discussed in detail.

The oxygen dissociation curve of blood in COVID-19-An update

An impressive effect of the infection with SARS-Co-19 is the impairment of oxygen uptake due to lung injury. The reduced oxygen diffusion may potentially be counteracted by an increase in oxygen affinity of hemoglobin. However, hypoxia and anemia associated with COVID-19 usually decrease oxygen affinity due to a rise in [2,3-bisphosphoglycerate]. As such, COVID-19 related changes in the oxygen dissociation curve may be critical for oxygen uptake and supply, but are hard to predict. A Pubmed search lists 14 publications on oxygen affinity in COVID-19. While some investigations show no changes, three large studies found an increased affinity that was related to a good prognosis. Exact causes remain unknown. The cause of the associated anemia in COVID-19 is under discussion. Erythrocytes with structural alterations of membrane and cytoskeleton have been observed, and virus binding to Band 3 and also to ACE2 receptors in erythroblasts has been proposed. COVID-19 presentation is moderate in many subjects suffering from sickle cell disease. A possible explanation is that COVID-19 counteracts the unfavorable large right shift of the oxygen dissociation curve in these patients. Under discussion for therapy are mainly affinity-increasing drugs.

SARS-CoV-2 infection augments species- and age-specific predispositions in cotton rats

Heterogeneity of COVID-19 manifestations in human population is vast, for reasons unknown. Cotton rats are a clinically relevant small animal model of human respiratory viral infections. Here, we demonstrate for the first time that SARS-CoV-2 infection in cotton rats affects multiple organs and systems, targeting species- and age-specific biological processes. Infection of S. fulviventer, which developed a neutralizing antibody response and were more susceptible to SARS-CoV-2 replication in the upper respiratory tract, was accompanied by hyperplasia of lacrimal drainage-associated lymphoid tissue (LDALT), a first known report of mucosa-associated lymphoid tissue activation at the portal of SARS-CoV-2 entry. Although less permissive to viral replication, S. hispidus showed hyperplasia of bone marrow in the facial bones and increased pulmonary thrombosis in aged males. Augmentation of these features by SARS-CoV-2 infection suggests a virus-induced breach in regulatory mechanisms which could be devastating for people of all ages with underlying conditions and in particular for elderly with a multitude of ongoing disorders.

COVID-19 screening with digital holographic microscopy using intra-patient probability functions of spatio-temporal bio-optical attributes

We present an automated method for COVID-19 screening using the intra-patient population distributions of bio-optical attributes extracted from digital holographic microscopy reconstructed red blood cells. Whereas previous approaches have aimed to identify infection by classifying individual cells, here, we propose an approach to incorporate the attribute distribution information from the population of a given human subjects' cells into our classification scheme and directly classify subjects at the patient level. To capture the intra-patient distribution information in a generalized way, we propose an approach based on the Bag-of-Features (BoF) methodology to transform histograms of bio-optical attribute distributions into feature vectors for classification via a linear support vector machine. We compare our approach with simpler classifiers directly using summary statistics such as mean, standard deviation, skewness, and kurtosis of the distributions. We also compare to a k-nearest neighbor classifier using the Kolmogorov-Smirnov distance as a distance metric between the attribute distributions of each subject. We lastly compare our approach to previously published methods for classification of individual red blood cells. In each case, the methodology proposed in this paper provides the highest patient classification performance, correctly classifying 22 out of 24 individuals and achieving 91.67% classification accuracy with 90.00% sensitivity and 92.86% specificity. The incorporation of distribution information for classification additionally led to the identification of a singular temporal-based bio-optical attribute capable of highly accurate patient classification. To the best of our knowledge, this is the first report of a machine learning approach using the intra-patient probability distribution information of bio-optical attributes obtained from digital holographic microscopy for disease screening.

Effects of Hypoxia on Respiratory Diseases: Perspective View of Epithelial Ion Transport

The balance of gas exchange and lung ventilation is essential for the maintenance of body homeostasis. There are many ion channels and transporters in respiratory epithelial cells, including epithelial sodium channel, Na,K-ATPase, cystic fibrosis transmembrane conductance regulator, and some transporters. These ion channels/transporters maintain the capacity of liquid layer on the surface of respiratory epithelial cells, and provide an immune barrier for the respiratory system to clear off foreign pathogens. However, in some harmful external environment and/or pathological conditions, the respiratory epithelium is prone to hypoxia, which would destroy the ion transport function of the epithelium and unbalance the homeostasis of internal environment, triggering a series of pathological reactions. Many respiratory diseases associated with hypoxia manifest an increased expression of hypoxia-inducible factor-1, which mediates the integrity of the epithelial barrier and affects epithelial ion transport function. It is important to study the relationship between hypoxia and ion transport function, whereas the mechanism of hypoxia-induced ion transport dysfunction in respiratory diseases is not clear. This review focuses on the relationship of hypoxia and respiratory diseases, as well as dysfunction of ion transport and tight junctions in respiratory epithelial cells under hypoxia.

Changes in the Blood Viscosity in Patients With SARS-CoV-2 Infection

Coronavirus disease 2019 (COVID-19) is caused by a novel virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2-induced hyperinflammation together with alteration of plasma proteins, erythrocyte deformability, and platelet activation, may affect blood viscosity. Thus, this review aimed to study the link between SARS-CoV-2 infection and alteration of blood viscosity in COVID-19 patients. In order to review findings related to hyperviscosity in COVID-19, we suggested a protocol for narrative review of related published COVID-19 articles. Hyperviscosity syndrome is developed in different hematological disorders including multiple myeloma, sickle cell anemia, Waldenstorm macroglobulinemia, polycythemia, and leukemia. In COVID-19, SARS-CoV-2 may affect erythrocyte morphology via binding of membrane cluster of differentiation 147 (CD147) receptors, and B and 3 proteins on the erythrocyte membrane. Variations in erythrocyte fragility and deformability with endothelial dysfunction and oxidative stress in SARS-CoV-2 infection may cause hyperviscosity syndrome in COVID-19. Of interest, hyperviscosity syndrome in COVID-19 may cause poor tissue perfusion, peripheral vascular resistance, and thrombosis. Most of the COVID-19 patients with a blood viscosity more than 3.5 cp may develop coagulation disorders. Of interest, hyperviscosity syndrome is more commonly developed in vaccine recipients who had formerly received the COVID-19 vaccine due to higher underlying immunoglobulin concentrations, and only infrequently in those who have not received the COVID-19 vaccine. Taken together, these observations are untimely too early to give a final connotation between COVID-19 vaccination and the risk for development of hyperviscosity syndrome, consequently prospective and retrospective studies are necessary in this regard.

Silent hypoxia is not an identifiable characteristic in patients with COVID-19 infection

Background

Methods

Results

Conclusions

Hyperviscosity syndrome in COVID-19 and related vaccines: exploring of uncertainties

Hyperviscosity syndrome (HVS) recently emerged as a complication of coronavirus disease 2019 (COVID-19) and COVID-19 vaccines. Therefore, the objectives of this critical review are to establish the association between COVID-19 and COVID-19 vaccines with the development of HVS. HVS may develop in various viral infections due to impairment of humoral and cellular immunity with elevation of immunoglobulins. COVID-19 can increase blood viscosity (BV) through modulation of fibrinogen, albumin, lipoproteins, and red blood cell (RBC) indices. HVS can cause cardiovascular and neurological complications in COVID-19 like myocardial infarction (MI) and stroke. HVS with or without abnormal RBCs function in COVID-19 participates in the reduction of tissue oxygenation with the development of cardio-metabolic complications and long COVID-19. Besides, HVS may develop in vaccine recipients with previous COVID-19 due to higher underlying Ig concentrations and rarely without previous COVID-19. Similarly, patients with metabolic syndrome are at the highest risk for propagation of HVS after COVID-19 vaccination. In conclusion, COVID-19 and related vaccines are linked with the development of HVS, mainly in patients with previous COVID-19 and underlying metabolic derangements. The possible mechanism of HVS in COVID-19 and related vaccines is increasing levels of fibrinogen and immunoglobulins. However, dehydration, oxidative stress, and inflammatory reactions are regarded as additional contributing factors in the pathogenesis of HVS in COVID-19. However, this critical review cannot determine the final causal relationship between COVID-19 and related vaccines and the development of HVS. Prospective and retrospective studies are warranted in this field.

Even patients with mild COVID-19 symptoms after SARS-CoV-2 infection show prolonged altered red blood cell morphology and rheological parameters

Infection with the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and the associated coronavirus disease-19 (COVID-19) might affect red blood cells (RBC); possibly altering oxygen supply. However, investigations of cell morphology and RBC rheological parameters during a mild disease course are lacking and thus, the aim of the study. Fifty individuals with mild COVID-19 disease process were tested after the acute phase of SARS-CoV-2 infection (37males/13 females), and the data were compared to n = 42 healthy controls (30 males/12 females). Analysis of venous blood samples, taken at rest, revealed a higher percentage of permanently elongated RBC and membrane extensions in COVID-19 patients. Haematological parameters and haemoglobin concentration, MCH and MCV in particular, were highly altered in COVID-19. RBC deformability and deformability under an osmotic gradient were significantly reduced in COVID-19 patients. Higher RBC-NOS activation was not capable to at least in part counteract these reductions. Impaired RBC deformability might also be related to morphological changes and/or increased oxidative state. RBC aggregation index remained unaffected. However, higher shear rates were necessary to balance the aggregation-disaggregation in COVID-19 patients which might be, among others, related to morphological changes. The data suggest prolonged modifications of the RBC system even during a mild COVID-19 disease course.

COVID-19 detection from red blood cells using highly comparative time-series analysis (HCTSA) in digital holographic microscopy

We present an automated method for COVID-19 screening based on reconstructed phase profiles of red blood cells (RBCs) and a highly comparative time-series analysis (HCTSA). Video digital holographic data -was obtained using a compact, field-portable shearing microscope to capture the temporal fluctuations and spatio-temporal dynamics of live RBCs. After numerical reconstruction of the digital holographic data, the optical volume is calculated at each timeframe of the reconstructed data to produce a time-series signal for each cell in our dataset. Over 6000 features are extracted on the time-varying optical volume sequences using the HCTSA to quantify the spatio-temporal behavior of the RBCs, then a linear support vector machine is used for classification of individual RBCs. Human subjects are then classified for COVID-19 based on the consensus of their cells' classifications. The proposed method is tested on a dataset of 1472 RBCs from 24 human subjects (10 COVID-19 positive, 14 healthy) collected at UConn Health Center. Following a cross-validation procedure, our system achieves 82.13% accuracy, with 92.72% sensitivity, and 73.21% specificity (area under the receiver operating characteristic curve: 0.8357). Furthermore, the proposed system resulted in 21 out of 24 human subjects correctly labeled. To the best of our knowledge this is the first report of a highly comparative time-series analysis using digital holographic microscopy data.

COVID-19 and erythrocrine function: The roller coaster and danger

Erythrocrine function refers to erythrocytes' ability to synthesize and release active signaling molecules such as ATP and nitric oxide (NO). Erythrocyte NO regulates its deformability and increases its perfusion and circulation that prevent tissue hypoxia. Recently, there is a connotation between SARS-CoV-2 infection and erythrocrine function due to alteration in the release of NO and ATP from erythrocytes. SARS-CoV-2 binds erythrocyte band3 protein, which has a similar characteristic of ACE2, leading to alteration of erythrocyte physiology like oxygen transport with development of hypoxia. Similarly, SARS-CoV-2 infection activates erythrocyte protein kinase C alpha (PKC-α), causing significant changes in the erythrocyte functions. The erythrocytes can bind SARS-CoV-2 and its active particles with subsequent virus delivery to the liver and spleen macrophages. Thus, the erythrocytes act as elimination for SARS-CoV-2 in COVID-19. Moreover, the erythrocyte stored, release sphingosine-1 phosphate (S1P) improves endothelial and regulates lymphocyte functions. SARS-CoV-2 ORF8 protein binds the porphyrin part of hemoglobin heme at the β1 chain, causing hemolysis and dysfunctional hemoglobin to reduce oxygen-carrying capacity. In conclusion, SARS-CoV-2 infection and associated pro-inflammatory disorders lead to abnormal erythrocrine function with subsequent inflammatory complications and endothelial dysfunction due to deficiency of protective released molecules (NO, G1P, and ATP) from functional erythrocytes. In vitro, preclinical, and clinical studies are mandatory in this regard.

Complete blood count alterations in COVID-19 patients: A narrative review

Coronavirus disease 2019 (COVID-19) pandemic represents a scientific and social crisis. One of the main unmet needs for coronavirus disease 2019 is its unpredictable clinical course, which can rapidly change in an irreversible outcome. COVID-19 patients can be classified into mild, moderate, and severe. Several haematological parameters, such as platelets, white blood cell total count, lymphocytes, neutrophils, (together with neutrophil-lymphocyte and platelet-lymphocyte ratio), and haemoglobin were described to be associated with COVID-19 infection and severity. The purpose of these review is to describe the current state of the art about complete blood count alterations during COVID-19 infection, and to summarize the crucial role of some haematological parameters during the course of the disease. Decreased platelet, lymphocyte, haemoglobin, eosinophil, and basophil count, increased neutrophil count and neutrophil-lymphocyte and platelet-lymphocyte ratio have been associated with COVID-19 infection and a worse clinical outcome. Our study adds some novelty about the identification of effective biomarkers of progressive disease, and might be helpful for diagnosis, prevention of complications, and effective therapy.

Promising gas therapies for severe COVID-19

The novel coronavirus disease 2019 (COVID-19) pandemic is a worldwide catastrophe, thoroughly challenging the healthcare systems. A growing number of victims suffer from a remarkable acute respiratory distress syndrome (ARDS) that necessitates admission to the intensive care unit (ICU), but there are no satisfactory treatments. Various gas therapies including nitric oxide, ozone, hyperbaric oxygen, hydrogen, and heliox have been employed in the fight against the pandemic and have improved clinical outcomes. However, the potential roles of these gases in COVID-19 treatment need to be verified in well-designed randomized controlled trials. This paper reviews advances in gaseous therapy of COVID-19.

Participation of nitrogen oxide and its metabolites in the genesis of hyperimmune inflammation in COVID-19

Despite the success in the tactics of treating COVID-19, there are many unexplored issues related to the development and progression of the process in the lungs, brain, and other organs, as well as the role of individual elements, in particular, nitric oxide (NO), and in the pathogenesis of organ damage. Based on the analyzed literature data, we considered a possible pathophysiological mechanism of action of NO and its derivatives in COVID-19. It can be noted that hyperimmune systemic inflammation and "cytokine storm" are enhanced by the production of NO, products of its oxidation ("nitrosative stress"). It is noted in the work that as a result of the oxidation of NO, a large amount of the toxic compound peroxynitrite is formed, which is a powerful proinflammatory agent. Its presence significantly damages the endothelium of the vascular walls and also oxidizes lipids, hemoglobin, myoglobin, and cytochrome, binds SH-groups of proteins, and damages DNA in the target cells. This is confirmed by the picture of the vessels of the lungs on computed tomography and the data of biochemical studies. In case of peroxynitrite overproduction, inhibition of the synthesis of NO and its metabolic products seems to be justified. Another aspect considered in this work is the mechanism of damage by the virus to the central and peripheral nervous system, which remains poorly understood but may be important in understanding the consequences, as well as predicting brain functions in persons who have undergone COVID-19. According to the analyzed literature, it can be concluded that brain damage is possible due to the direct effect of the virus on the peripheral nerves and central structures, and indirectly through the effect on the endothelium of cerebral vessels. Disturbances in the central nervous regulation of immune responses may be associated with the insufficient function of the acetylcholine anti-inflammatory system. It is proposed to further study several approaches to influence various links of NO exchange, which are of interest for theoretical and practical medicine.

Consequences of coronavirus infections for primitive and mature hematopoietic cells: new insights and why it matters

PURPOSE OF REVIEW

In recent history there have been three outbreaks of betacoronavirus infections in humans, with the most recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; causing Coronavirus disease 2019 [COVID-19]) outbreak leading to over two million deaths, with a rapidly rising death toll. Much remains unknown about host cells and tissues affected by coronavirus infections, including the hematopoietic system. Here, we discuss the recent findings examining effects that coronavirus infection or exposure has on hematopoietic cells and the clinical implications for these effects.

RECENT FINDINGS

Recent studies have centered on SARS-CoV-2, demonstrating that hematopoietic stem and progenitor cells and mature immune cells may be susceptible to infection and are impacted functionally by exposure to SARS-CoV-2 Spike protein. These findings have important implications regarding hematologic complications arising from COVID-19 and other coronavirus-induced disease, which we discuss here.

SUMMARY

Infection with coronaviruses sometimes leads to hematologic complications in patients, and these hematologic complications are associated with poorer prognosis. These hematologic complications may be caused by coronavirus direct infection or impact on primitive hematopoietic cells or mature immune cells, by indirect effects on these cells, or by a combination thereof. It is important to understand how hematologic complications arise in order to seek new treatments to improve patient outcomes.

SARS-CoV-2 mediated neuroinflammation and the impact of COVID-19 in neurological disorders

SARS-CoV-2 is a novel coronavirus that severely affects the respiratory system, is the cause of the COVID-19 pandemic, and is projected to result in the deaths of 2 million people worldwide. Recent reports suggest that SARS-CoV-2 also affects the central nervous system along with other organs. COVID-19-associated complications are observed in older people with underlying neurological conditions like stroke, Alzheimer's disease, and Parkinson's disease. Hence, we discuss SARS-CoV-2 viral replication and its inflammation-mediated infection. This review also focuses on COVID-19 associated neurological complications in individuals with those complications as well as other groups of people. Finally, we also briefly discuss the current therapies available to treat patients, as well as ongoing available treatments and vaccines for effective cures with a special focus on the therapeutic potential of a small 5 amino acid peptide (PHSCN), ATN-161, that inhibits SARS-CoV-2 spike protein binding to both integrin α5β1 and α5β1/hACE2.