Differential Cytokine Responses in Hospitalized COVID-19 Patients Limit Efficacy of Remdesivir

COVID-19 in patients with multiple sclerosis-A narrative review

BACKGROUND

Multiple sclerosis (MS) is a complex neurodegenerative disease characterized by immune dysregulation, affecting over 2.5 million people worldwide. Interestingly, COVID-19 infection can cause neurodegeneration through demyelination similar to that of MS, and COVID-19 infection can lead to long-term neurological sequelae, post-COVID-19 neurological syndrome. These overlapping neurological mechanisms suggest that patients with MS (PwMS) may have a unique and potentially more complex relationship with COVID-19.

DISCUSSION AND CONCLUSION

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can enter the central nervous system via the olfactory nerve or through interactions with angiotensin-converting enzyme-2 receptors in the blood-brain barrier, potentially initiating or enhancing neurodegenerative processes through demyelination. The risk of SARS-CoV-2 infection among PwMS is similar to that of the general population; however, PwMS with higher Expanded Disability Status Scale scores, longer MS duration, or progressive forms of MS are at an increased risk for developing severe COVID-19 outcomes. Most disease-modifying therapies (DMT), such as interferon, glatiramer, teriflunomide, and cladribine, do not appear to affect the risk of COVID-19 infection, the severity of COVID-19 illness, or the response to COVID-19 vaccines. As a result, these therapies should be continued during COVID-19 infection in PwMS. Rituximab, however, has been shown to increase the risk of severe COVID-19 outcomes. For managing symptomatic COVID-19 infection in PwMS, remdesivir and neutralizing monoclonal antibodies are shown to be effective. COVID-19-associated cytokine release syndrome can be managed with corticosteroids. Importantly, COVID-19 infection does not increase susceptibility to MS relapses or exacerbate the progression of MS symptoms. Furthermore, COVID-19 vaccination is encouraged for all MS patients, particularly those at greater risk of severe outcomes, as it does not trigger relapses, exacerbate MS symptoms, or diminish the efficacy of DMT. Despite these findings, high-quality evidence remains lacking to fully establish the relationship between COVID-19 and MS, highlighting the need for further research in this area.

Differential Cytokine Responses of APOE3 and APOE4 Blood-brain Barrier Cell Types to SARS-CoV-2 Spike Proteins

SARS-CoV-2 spike proteins have been shown to cross the blood-brain barrier (BBB) in mice and affect the integrity of human BBB cell models. However, the effects of SARS-CoV-2 spike proteins in relation to sporadic, late onset, Alzheimer's disease (AD) risk have not been extensively investigated. Here we characterized the individual and combined effects of SARS-CoV-2 spike protein subunits S1 RBD, S1 and S2 on BBB cell types (induced brain endothelial-like cells (iBECs) and astrocytes (iAstrocytes)) generated from induced pluripotent stem cells (iPSCs) harboring low (APOE3 carrier) or high (APOE4 carrier) relative Alzheimer's risk. We found that treatment with spike proteins did not alter iBEC integrity, although they induced the expression of several inflammatory cytokines. iAstrocytes exhibited a robust inflammatory response to SARS-CoV-2 spike protein treatment, with differences found in the levels of cytokine secretion between spike protein-treated APOE3 and APOE4 iAstrocytes. Finally, we tested the effects of potentially anti-inflammatory drugs during SARS-CoV-2 spike protein exposure in iAstrocytes, and discovered different responses between spike protein treated APOE4 iAstrocytes and APOE3 iAstrocytes, specifically in relation to IL-6, IL-8 and CCL2 secretion. Overall, our results indicate that APOE3 and APOE4 iAstrocytes respond differently to anti-inflammatory drug treatment during SARS-CoV-2 spike protein exposure with potential implications to therapeutic responses.

Evaluation of the relationship between serum BDNF concentration and indicators of oxidative stress and inflammation in COVID-19 patients with neurological disorders - a pilot study

INTRODUCTION

The aim of this study was to determine the effect of serum level of brain-derived neurotrophic factor (BDNF) on the development of neurological disorders in COVID-19 patients and the probable role of oxidative stress and inflammation in this phenomenon.

METHODS

The present case-control study included 42 COVID-19 patients referring to Golestan and Sina hospitals of Ahvaz, Iran, for treatment. Patients with (n = 18) and without (n = 24) neurological disorders were allocated into test and control groups, respectively. Following blood sampling, serum isolation was done, and the serum was stored at -80°C until biochemical assessment for measuring BDNF, oxidative stress indices, and inflammatory factors.

RESULTS

Although no significant brain damage was observed in the COVID-19 patients with neurological disorders, the results showed that the serum level of BDNF in the test group increased compared to that in the control group, and this increment was accompanied with increased Tumor Necrosis Factor-alpha (TNF-α) and decreased Interferon gamma (IFN-γ) levels in the serum. Moreover, compared to the control group, patients in the test group had a decreased level of Thiol and an increased level of Malondialdehyde (MDA) in the serum. Furthermore, there was a significant positive correlation between the serum concentration of BDNF and nitric oxide (NO) in the test group.

CONCLUSION

Using over-the-counter (OTC) medicines which include thiol-group-related agents or any other antioxidants can alleviate oxidative stress and the associated increased inflammation in COVID-19 patients with neurological symptoms.

Oxidative stress and COVID-19-associated neuronal dysfunction: mechanisms and therapeutic implications

Severe acute respiratory syndrome (SARS)-CoV-2 virus causes novel coronavirus disease 2019 (COVID-19), and there is a possible role for oxidative stress in the pathophysiology of neurological diseases associated with COVID-19. Excessive oxidative stress could be responsible for the thrombosis and other neuronal dysfunctions observed in COVID-19. This review discusses the role of oxidative stress associated with SARS-CoV-2 and the mechanisms involved. Furthermore, the various therapeutics implicated in treating COVID-19 and the oxidative stress that contributes to the etiology and pathogenesis of COVID-19-induced neuronal dysfunction are discussed. Further mechanistic and clinical research to combat COVID-19 is warranted to understand the exact mechanisms, and its true clinical effects need to be investigated to minimize neurological complications from COVID-19.

Th-1, Th-2, Th-9, Th-17, Th-22 type cytokine concentrations of critical COVID-19 patients after treatment with Remdesivir

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the world causing a pandemic known as coronavirus disease 2019 (COVID-19). Cytokine storm was directly correlated with severity of COVID-19 syndromes. We evaluated the levels of 13 cytokines in ICU hospitalized COVID-19 patients (n=29) before, and after treatment with Remdesivir as well as in healthy controls (n=29). Blood samples were obtained from ICU patients during ICU admission (before treatment) and 5 days after treatment with Remdesivir. A group of 29 age- and gender-matched healthy controls was also studied. Cytokine levels were evaluated by multiplex immunoassay method using a fluorescence labeled cytokine panel. In comparison to cytokine levels measured at ICU admission, serum levels were reduced of IL-6 (134.75 pg/mL vs. 20.73 pg/mL, P< 0.0001), TNF-α (121.67 pg/mL vs. 10.15 pg/mL, P< 0.0001) and IFN-γ (29.69 pg/mL vs. 22.27 pg/mL, P= 0.005), whereas serum level was increased of IL-4 (8.47 pg/mL vs. 12.44 pg/mL, P= 0.002) within 5 days after Remdesivir treatment. Comparing with before treatment, Remdesivir significantly reduced the levels of inflammatory (258.98 pg/mL vs. 37.43 pg/mL, P< 0.0001), Th1-type (31.24 pg/mL vs. 24.46 pg/mL, P= 0.007), and Th17-type (36.79 pg/mL vs. 26.22 pg/mL, P< 0.0001) cytokines in critical COVID-19 patients. However, after Remdesivir treatment, the concentrations of Th2-type cytokines were significantly higher than before treatment (52.69 pg/mL vs. 37.09 pg/mL, P< 0.0001). In conclusion, Remdesivir led to decrease levels of Th1-type and Th17-type cytokines and increase Th2-type cytokines in critical COVID-19 patients 5 days after treatment.

Immune and pathophysiologic profiling of antenatal coronavirus disease 2019 in the GIFT cohort: A Singaporean case-control study

COVID-19 can be severe in pregnant women, and have adverse consequences for the subsequent infant. We profiled the post-infectious immune responses in maternal and child blood as well as breast milk in terms of antibody and cytokine expression and performed histopathological studies on placentae obtained from mothers convalescent from antenatal COVID-19. Seventeen mother-child dyads (8 cases of antenatal COVID-19 and 9 healthy unrelated controls; 34 individuals in total) were recruited to the Gestational Immunity For Transfer (GIFT) study. Maternal and infant blood, and breast milk samples were collected over the first year of life. All samples were analyzed for IgG and IgA against whole SARS-CoV-2 spike protein, the spike receptor-binding domain (RBD), and previously reported immunodominant epitopes, as well as cytokine levels. The placentae were examined microscopically. The study is registered at clinicaltrials.gov under the identifier NCT04802278. We found high levels of virus-specific IgG in convalescent mothers and similarly elevated titers in newborn children. Thus, antenatal SARS-CoV-2 infection led to high plasma titers of virus-specific antibodies in infants postnatally. However, this waned within 3-6 months of life. Virus neutralization by plasma was not uniformly achieved, and the presence of antibodies targeting known immunodominant epitopes did not assure neutralization. Virus-specific IgA levels were variable among convalescent individuals' sera and breast milk. Antibody transfer ratios and the decay of transplacentally transferred virus-specific antibodies in neonatal circulation resembled that for other pathogens. Convalescent mothers showed signs of chronic inflammation marked by persistently elevated IL17RA levels in their blood. Four placentae presented signs of acute inflammation, particularly in the subchorionic region, marked by neutrophil infiltration even though > 50 days had elapsed between virus clearance and delivery. Administration of a single dose of BNT162b2 mRNA vaccine to mothers convalescent from antenatal COVID-19 increased virus-specific IgG and IgA titers in breast milk, highlighting the importance of receiving the vaccine even after natural infection with the added benefit of enhanced passive immunity.

Cytokine Storm Signature in Patients with Moderate and Severe COVID-19

Hypercytokinemia, found in SARS-CoV-2 infection, contributes to multiple organ dysfunctions with acute respiratory distress syndrome, shock etc. The aim of this study was to describe cytokine storm signatures in patients with acute COVID-19 and to investigate their influence on severity of the infection. Plasma levels of 47 cytokines were investigated in 73 patients with moderate and severe COVID-19 (41 and 32, respectively) and 11 healthy donors (HD). The most elevated levels comparing patients and the HD were observed for seven pro-inflammatory cytokines (IL-6, IL-8, IL-15, IL-18, IL-27, IFNγ, TNFα), three chemokines (GROα, IP-10, MIG), two anti-inflammatory cytokines (IL-1RA, IL-10), and two growth factors (G-CSF, M-CSF). The patients with severe disease had significantly higher levels of FGF-2/FGF-basic, IL-1β, and IL-7 compared to the HD. The two groups of patients differed from each other only based on the levels of EGF, eotaxin, and IL-12 p40. Pneumonia lung injury, characterized by computer tomography, positively correlated with levels of EGF, IP-10, MCP-3 levels and negatively with IL-12 p40. Pro-inflammatory factors including IL-6, TNFα, and IP-10 negatively correlated with the frequency of the circulating T-helper17-like cells (Th17-like) and follicular Th cells that are crucial to develop SARS-CoV-2-specific plasma cells and memory B cells. Obtained data on the cytokine levels illustrate their influence on progression and severity of COVID-19.

Serum Brain-Derived Neurotrophic Factor (BDNF) in COVID-19 Patients and its Association with the COVID-19 Manifestations

COVID-19 is a systematic disease that frequently implies neurological and non-neurological manifestations, predominantly by inducing hypoxia. Brain-derived neurotrophic factor (BDNF) is a key factor in regulating functions of nervous and respiratory systems and has been strongly related to hypoxia. Therefore, this study planned to investigate BDNF association with the COVID-19 manifestations especially neurological impairments and the infection-induced hypoxia. We enrolled sixty-four COVID-19 patients and twenty-four healthy individuals in this study. Patients were divided into two groups, with and without neurological manifestations, and their serum BDNF levels were measured by enzyme-linked immunosorbent assay (ELISA). COVID-19 patients had significantly lower BDNF levels than healthy individuals (p = 0.023). BDNF levels were significantly lower in patients with neurological manifestations compared to healthy individuals (p = 0.010). However, we did not observe a statistically significant difference in BDNF levels between patients with and without neurological manifestations (p = 0.175). BDNF’s levels were significantly lower in patients with CNS manifestations (p = 0.039) and higher in patients with fever (p = 0.03) and dyspnea (p = 0.006). Secondly, BDNF levels have a significant negative association with oxygen therapy requirement (p = 0.015). These results strongly suggest the critical association between dysregulated BDNF and hypoxia in promoting COVID-19 manifestations, particularly neurological impairments.