Low molecular weight cytotoxic components (DAMPs) form the post-COVID-19 syndrome

Abstract:

We studied the role of cytotoxic components (DAMPs) formed in the body of patients with COVID-19 in ensuring the long-term preservation of post-COVID-19 manifestations and the possibility of creating an experimental model by transferring DAMPs to rats. In patients with post-COVID-19 syndrome (PCS) 2 months after SARS-CoV-2 infection we determined the presence of cytotoxic components in the blood serum (Terasaki test, Dunaliella viridis test and content of DAMPs).

In post-COVID-19 syndrome patients with a high content of serum cytotoxic oligopeptide fraction (selective group, n = 16) we determined the number of leukocytes, lymphocytes, neutrophil granulocytes and monocytes in the blood, the content of C-reactive protein (CRP), the concentration of C3 and C4 complement components and circulating immune complexes, the serum content of IL-6, IL -10, IL-18, TNF-α, phagocytic activity of neutrophils, presence of neutrophil traps and autoantibodies ANA.

It has been shown that in patients with PCS, there are components with cytotoxicity in the blood serum, form specific immunopathological patterns, which are characterized by: an increased content of CRP, complement system components C3 and C4 and cytokines (TNF-α, IL-6, IL-10, IL-18) activation, the formation of a wide range of autoantibodies ANA, the low efficiency of endocytosis in oxygen-independent phagocytosis; their phagocytic activity reaches its functional limit, and against this background, activation of neutrophil traps occurs, which can contribute to further induction of DAMPs. This self-sustaining cell-killing activation provided long-term preservation of PCS symptoms.

The transfer of blood serum components from selective group patients with PCS to rats was accompanied by the appearance of cytotoxic components in them which induced sensitization and immunopathological reactions. Preventive administration of a biologically active substance with polyfunctional properties MF to experimental animals “corrected” the initial functional state of the body’s immune-metabolic system and eliminated or facilitated immuno-inflammatory reactions.

Source: Klimova EM, Bozhkov AI, Lavinska OV, Drozdova LA, Kurhuzova NI. Low molecular weight cytotoxic components (DAMPs) form the post-COVID-19 syndrome. Immunobiology. 2023 Jan;228(1):152316. doi: 10.1016/j.imbio.2022.152316. Epub 2022 Dec 20. PMID: 36565610; PMCID: PMC9764760. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9764760/ (Full text)

The Role of Leptin and Inflammatory Related Biomarkers in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Purpose: Leptin is a member of the cytokine family; its receptor (LEPR-b) is the longest form receptor expressed in cells of the immune system; wherein LEPR-b deficiency causes a decrease in CD4+ cells. LEPR-b is located in hypothalamic and brain stem nuclei, and it primarily regulates energy status. As well, leptin indirectly regulates widespread pain and exercise tolerance by decreasing circulating cortisol.

Hyperinsulinemia increases leptin production in adipocytes on a diurnal rhythm; however, the precise relationship between insulin, leptin and pro-inflammatory markers remains uncertain. In clinical settings, high-sensitivity C-reactive protein (hsCRP) has been widely used, as an inflammatory predictor for leptin-related cardiometabolic outcomes and chronic inflammatory symptoms.

Leptin-related metabolic and inflammation dysregulations have been clinically reported in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), but not fully elucidated. We examined the association of plasma insulin, leptin, and hsCRP levels with ME/CFS self-reported symptom severity.

Methods: Prospective analyses were conducted on ME/CFS patients who met Fukuda/CDC criteria at Birmingham hospital, Alabama, U.S.A. The independent variables were hyperinsulinemia (>174 μIU/mL), hyperleptinemia/hypoleptinemia (>18.3/<3.3 ng/mL), residual inflammation risk (hsCRP ≥2 and ≠26.2 mg/L) and within-individual-variability (WIV) for each biomarker.

WIV was defined for each individual as standard deviation/sample residuals adjusting for time and calculated from once-daily random plasma samples over 10–12 weeks.

The primary outcomes were:

(1) ME/CFS symptom score trends [generalized pain, persistent fatigue, sleep disturbance, impairment of concentration and memory (brain fog), and post-exertional malaise (PEM)] calculated from the MFI-20 questionnaire with anchors from 0 to 100 and recorded once daily over a matching 12–14 weeks, and

(2) dichotomized symptom severity, with severe symptoms defined as scores > 60/100. After adjusting for age and time, we reported: (1) standard errors (SEM) and p-values for symptom trends using multivariable mixed-effect linear regression models, and (2) odds ratios for severe symptoms using multivariable alternating logistic regression models.

Results: We included 29 ME/CFS patients. All were females and >18 years old. Hyperinsulinemia, hyperleptinemia/hypoleptinemia, and residual inflammation risk were 7%, 80%/7%, and 74%, respectively.

The medians of insulin-WIV, leptin-WIV and hsCRP-WIV were [(0.24; IQR 0.15–0.38), (0.25; IQR 0.15–0.40), (0.33; IQR 0.18–0.51)] respectively. On average, hyperleptinemic patients had the highest leptin-WIV and 50% of them had residual inflammation risk.

Severe (fatigue, pain, brain fog, sleep disturbance, and PEM) were reported in 50%, 29%, 41%, 30%, and 57% of patients, respectively. In the adjusted analysis, worse fatigue scores (7.49; SEM, 2.23; p = 0.002) were associated with higher insulin-WIV.

Hyperleptinemia (OR 1.54; 95% CI 1.13–2.09) compared to hypoleptinemia, and residual inflammation risk (OR 1.65; 95% CI 1.21–2.25) were associated with higher odds of severe fatigue. Worse pain scores (7.17; SEM, 2.30; p = 0.005) were associated with higher leptin-WIV, and (8.45; SEM, 2.25; p = 0.0009) higher hsCRP-WIV, and residual inflammation risk (OR 1.75; 95% CI 1.34–2.29) was associated with higher odds of severe pain.

Severe brain fog scores (9.20; SEM, 2.44; p = 0.0008) were associated with higher insulin-WIV, higher leptin-WIV (4.73; SEM, 2.12; p = 0.03). Residual inflammation risk (OR 1.40; 95% CI 1.16–1.77) was associated with higher odds of severe brain fog.

Hyperleptinemia (OR 0.60; 95% CI 0.43–1.19) was associated with lower odds of severe PEM compared to hypoleptinemia, and better sleep quality was associated (6.07; SEM, 1.70; p = 0.001) with higher insulin-WIV, and (3.37; SEM, 1.47; p = 0.03) higher leptin-WIV.

Conclusions: In patients with ME/CFS, symptoms severity was associated with hyperleptinemia, inflammation and within-individual-variability of these biomarkers. Leptin and hsCRP may be clinically useful in predicting symptom severity.

Larger clinical trials are needed to further examine the prediction and causality of these biomarkers in the development of ME/CFS diagnosis. The efficacy and safety of anti-inflammatory therapies may be evaluated in sub-clusters of ME/CFS with metabolic responses and inflammation dysregulations to improve patient-reported symptoms.

Source: Rahaf Al Assil and Jarred W Younger. “The Role of Leptin and Inflammatory Related Biomarkers in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome” in Karandrea S, Agarwal N, Organizing Committee of Cardiometabolic Health Congress. Report from the Scientific Poster Session at the 16th Annual Cardiometabolic Health Congress in National Harbor, USA, 14–17 October 2021. Proceedings. 2022; 80(1):6. https://doi.org/10.3390/proceedings2022080006 (Full text)

Role of neuroinflammation mediated potential alterations in adult neurogenesis as a factor for neuropsychiatric symptoms in Post-Acute COVID-19 syndrome-A narrative review

Abstract:

Persistence of symptoms beyond the initial 3 to 4 weeks after infection is defined as post-acute COVID-19 syndrome (PACS). A wide range of neuropsychiatric symptoms like anxiety, depression, post-traumatic stress disorder, sleep disorders and cognitive disturbances have been observed in PACS. The review was conducted based on PRISMA-S guidelines for literature search strategy for systematic reviews.

A cytokine storm in COVID-19 may cause a breach in the blood brain barrier leading to cytokine and SARS-CoV-2 entry into the brain. This triggers an immune response in the brain by activating microglia, astrocytes, and other immune cells leading to neuroinflammation. Various inflammatory biomarkers like inflammatory cytokines, chemokines, acute phase proteins and adhesion molecules have been implicated in psychiatric disorders and play a major role in the precipitation of neuropsychiatric symptoms. Impaired adult neurogenesis has been linked with a variety of disorders like depression, anxiety, cognitive decline, and dementia.

Persistence of neuroinflammation was observed in COVID-19 survivors 3 months after recovery. Chronic neuroinflammation alters adult neurogenesis with pro-inflammatory cytokines supressing anti-inflammatory cytokines and chemokines favouring adult neurogenesis. Based on the prevalence of neuropsychiatric symptoms/disorders in PACS, there is more possibility for a potential impairment in adult neurogenesis in COVID-19 survivors. This narrative review aims to discuss the various neuroinflammatory processes during PACS and its effect on adult neurogenesis.

Source: Saikarthik J, Saraswathi I, Alarifi A, Al-Atram AA, Mickeymaray S, Paramasivam A, Shaikh S, Jeraud M, Alothaim AS. Role of neuroinflammation mediated potential alterations in adult neurogenesis as a factor for neuropsychiatric symptoms in Post-Acute COVID-19 syndrome-A narrative review. PeerJ. 2022 Nov 4;10:e14227. doi: 10.7717/peerj.14227. PMID: 36353605; PMCID: PMC9639419. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9639419/ (Full text)

The SARS-CoV-2 S1 Spike Protein Promotes MAPK and NF-kB Activation in Human Lung Cells and Inflammatory Cytokine Production in Human Lung and Intestinal Epithelial Cells

The coronavirus disease 2019 (COVID-19) pandemic began in January 2020 in Wuhan, China, with a new coronavirus designated SARS-CoV-2. The principal cause of death from COVID-19 disease quickly emerged as acute respiratory distress syndrome (ARDS). A key ARDS pathogenic mechanism is the “Cytokine Storm”, which is a dramatic increase in inflammatory cytokines in the blood.
In the last two years of the pandemic, a new pathology has emerged in some COVID-19 survivors, in which a variety of long-term symptoms occur, a condition called post-acute sequelae of COVID-19 (PASC) or “Long COVID”. Therefore, there is an urgent need to better understand the mechanisms of the virus.
The spike protein on the surface of the virus is composed of joined S1–S2 subunits. Upon S1 binding to the ACE2 receptor on human cells, the S1 subunit is cleaved and the S2 subunit mediates the entry of the virus. The S1 protein is then released into the blood, which might be one of the pivotal triggers for the initiation and/or perpetuation of the cytokine storm.
In this study, we tested the hypothesis that the S1 spike protein is sufficient to activate inflammatory signaling and cytokine production, independent of the virus. Our data support a possible role for the S1 spike protein in the activation of inflammatory signaling and cytokine production in human lung and intestinal epithelial cells in culture. These data support a potential role for the SARS-CoV-2 S1 spike protein in COVID-19 pathogenesis and PASC.
Source: Forsyth CB, Zhang L, Bhushan A, Swanson B, Zhang L, Mamede JI, Voigt RM, Shaikh M, Engen PA, Keshavarzian A. The SARS-CoV-2 S1 Spike Protein Promotes MAPK and NF-kB Activation in Human Lung Cells and Inflammatory Cytokine Production in Human Lung and Intestinal Epithelial Cells. Microorganisms. 2022; 10(10):1996. https://doi.org/10.3390/microorganisms10101996 https://www.mdpi.com/2076-2607/10/10/1996/htm (Full text)

Plasma cytokine levels reveal deficiencies in IL-8 and gamma interferon in Long-COVID

Abstract:

Up to half of individuals who contract SARS-CoV-2 develop symptoms of long-COVID approximately three months after initial infection. These symptoms are highly variable, and the mechanisms inducing them are yet to be understood.

We compared plasma cytokine levels from individuals with long-COVID to healthy individuals and found that those with long-COVID had 100% reductions in circulating levels of interferon gamma (IFNγ) and interleukin-8 (IL-8). Additionally, we found significant reductions in levels of IL-6, IL-2, IL-17, IL-13, and IL-4 in individuals with long-COVID.

We propose immune exhaustion as the driver of long-COVID, with the complete absence of IFNγ and IL-8 preventing the lungs and other organs from healing after acute infection, and reducing the ability to fight off subsequent infections, both contributing to the myriad of symptoms suffered by those with long-COVID.

Source: Williams ESCP, Martins TB, Hill HR, Coiras M, Shah KS, Planelles V, Spivak AM. Plasma cytokine levels reveal deficiencies in IL-8 and gamma interferon in Long-COVID. medRxiv [Preprint]. 2022 Oct 5:2022.10.03.22280661. doi: 10.1101/2022.10.03.22280661. PMID: 36238724; PMCID: PMC9558442. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9558442/ (Full text)

Epipharyngeal Abrasive Therapy (EAT) Reduces the mRNA Expression of Major Proinflammatory Cytokine IL-6 in Chronic Epipharyngitis

Abstract:

The epipharynx, located behind the nasal cavity, is responsible for upper respiratory tract immunity; however, it is also the site of frequent acute and chronic inflammation. Previous reports have suggested that chronic epipharyngitis is involved not only in local symptoms such as cough and postnasal drip, but also in systemic inflammatory diseases such as IgA nephropathy and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long COVID.

Epipharyngeal Abrasive Therapy (EAT), which is an effective treatment for chronic epipharyngitis in Japan, is reported to be effective for these intractable diseases. The sedation of chronic epipharyngitis by EAT induces suppression of the inflammatory cytokines and improves systemic symptoms, which is considered to be one of the mechanisms, but there is no report that has proved this hypothesis. The purpose of this study was to clarify the anti-inflammatory effect of EAT histologically.

The study subjects were 8 patients who were not treated with EAT and 11 patients who were treated with EAT for chronic epipharyngitis for 1 month or more. For immunohistochemical assessment, the expression pattern of IL-6 mRNA, which plays a central role in the human cytokine network, was analyzed using in situ hybridization. The expression of IL-6 in the EAT-treated group was significantly lower than those in the EAT nontreated group (p = 0.0015). In addition, EAT suppressed the expression of tumor necrosis factor alpha (TNFα), a crucial proinflammatory cytokine. As a result, continuous EAT suppressed submucosal cell aggregation and reduced inflammatory cytokines. Thus, EAT may contribute to the improvement of systemic inflammatory diseases through the suppression of IL-6 expression.

Source: Nishi K, Yoshimoto S, Nishi S, Nishi T, Nishi R, Tanaka T, Tsunoda T, Imai K, Tanaka H, Hotta O, Tanaka A, Hiromatsu K, Shirasawa S, Nakagawa T, Yamano T. Epipharyngeal Abrasive Therapy (EAT) Reduces the mRNA Expression of Major Proinflammatory Cytokine IL-6 in Chronic Epipharyngitis. Int J Mol Sci. 2022 Aug 16;23(16):9205. doi: 10.3390/ijms23169205. PMID: 36012469; PMCID: PMC9409341. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9409341/ (Full text)

Inflammation and autoreactivity define a discrete subset of patients with post-acute sequelae of COVID-19, or long-COVID

Abstract:

While significant attention has been paid to the immunologic determinants of disease states associated with COVID-19, their contributions to post-acute sequelae of COVID-19 (PASC) remain less clear. Due to the wide array of PASC presentations, it is critical to understand if specific features of the disease are associated with discrete immune processes, and whether those processes may be therapeutically targeted. To this end, we performed wide immunologic and serological characterization of patients in the early recovery phase of COVID-19 across a breadth of symptomatic presentations.

Using high-parameter proteomics screening and applied machine learning (ML), we identify clear signatures of immunologic activity between PASC patients and uncomplicated recovery, dominated by inflammatory cytokine signaling, neutrophil activity, and markers of cell death. Consistent with disease complexity, heterogeneity in plasma profiling reveals distinct PASC subsets with striking divergence in these ongoing inflammatory processes, here termed plasma quiescent (plaq) and inflammatory (infl) PASC.

In addition to elevated inflammatory blood proteomics, inflPASC patients display positive clinical tests of acute inflammation including C-reactive protein and fibrinogen, increased B cell activity with extrafollicular involvement coupled with elevated targeting of viral nucleocapsid protein and clinical autoreactivity. Further, the unique plasma signatures of PASC patients allowed for the creation of refined models with high sensitivity and specificity for the positive identification of inflPASC with a streamlined assessment of 12 blood markers. Additionally, refined ML modeling highlights the unexpected significance of several markers of potential diagnostic or therapeutic use for PASC in general, including the peptide hormone, epiregulin.

In all, this work identifies clear biological signatures of PASC with potential diagnostic and therapeutic potential and establishes clear disease subtypes that are both easily identifiable and highly relevant to ongoing efforts in both therapeutic targeting and epidemiological investigation of this highly complex disease.

Source: Matthew Woodruff, Kevin S Bonham, Fabliha A Anam, Tiffany Walker, Yusho Ishii, Candice Y Kaminski, Martin Runnstrom, Alexander Truong, Adviteeya Dixit, Jenny Han, Richard Ramonell, Natalie S. Haddad, Mark Rudoloph, Arezou Khosroshahi, Scott A Jenks, F. Eun-Hyung Lee, Ignacio Sanz. Inflammation and autoreactivity define a discrete subset of patients with post-acute sequelae of COVID-19, or long-COVID. medRxiv 2021.09.21.21263845; doi: https://doi.org/10.1101/2021.09.21.21263845.  (Full text available as PDF file)

Current knowledge about Chronic fatigue syndrome / myalgic encephalomyelitis (CFS/ME) causes – summary

Abstract:

Chronic Fatigue Syndrome (CFE) is a severe and disabling disease whose etiology has not yet been elucidated. This implies the lack of a specific biomarker for the diagnosis of PE, and no causal treatment.

There are a number of diagnostic criteria that facilitate the diagnosis of PE, but it is still a diagnosis with exclusion. This chapter reviews the scientific literature systematically, summarizing the available knowledge about the probable etiology of Chronic Fatigue Syndrome.

The current topic of the influence of SARS-Cov-2 virus infection on the development of symptoms of IPC was also taken into account in particular.

A clear explanation of the etiology of PE is necessary for the further development of scientific knowledge about the Chronic Fatigue Syndrome.

Source: PRYLIŃSKA-JAŚKOWIAK, Monika & KOŻUCHOWSKI, Marcin. Current knowledge about Chronic fatigue syndrome / myalgic encephalomyelitis (CFS/ME) causes – summary. Journal of Education, Health and Sport [online]. 13 September 2022, T. 12, nr 9, s. 712–719. [accessed 26.9.2022]. DOI 10.12775/JEHS.2022.12.09.084.  https://apcz.umk.pl/JEHS/article/view/39954 https://apcz.umk.pl/JEHS/article/view/39954/33214 (Full text)

Exosome-Associated Mitochondrial DNA from Patients with ME/CFS Stimulates Human Cultured Microglia to Release IL-1β

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating disease that presents with fatigue, sleep disturbances, malaise, and cognitive problems. The pathogenesis of ME/CFS is presently unknown and serum levels of potential biomarkers have been inconsistent. Here we show that mitochondrial DNA (mtDNA) associated with serum exosomes, is increased in ME/CFS patients only after exercise. Moreover, exosomes isolated from patients with ME/CFS stimulate significant release of IL-1β from cultured human microglia. These results provide evidence that activation of microglia by serum-derived exosomes may serve as a potential novel pathogenetic factor and target for treatment of ME/CFS.

Source: Tsilioni I, Natelson B, Theoharides TC. Exosome-Associated Mitochondrial DNA from Patients with ME/CFS Stimulates Human Cultured Microglia to Release IL-1β. Eur J Neurosci. 2022 Sep 24. doi: 10.1111/ejn.15828. Epub ahead of print. PMID: 36153118. https://pubmed.ncbi.nlm.nih.gov/36153118/

Cytokine Profiles Associated With Acute COVID-19 and Long COVID-19 Syndrome

Abstract:

The duration and severity of COVID-19 are related to age, comorbidities, and cytokine synthesis. This study evaluated the impact of these factors on patients with clinical presentations of COVID-19 in a Brazilian cohort.

A total of 317 patients diagnosed with COVID-19 were included; cases were distributed according to clinical status as severe (n=91), moderate (n=56) and mild (n=170). Of these patients, 92 had acute COVID-19 at sample collection, 90 had already recovered from COVID-19 without sequelae, and 135 had sequelae (long COVID syndrome).

In the acute COVID-19 group, patients with the severe form had higher IL-6 levels (p=0.0260). In the post-COVID-19 group, there was no significant difference in cytokine levels between groups with different clinical conditions. In the acute COVID-19 group, younger patients had higher levels of TNF-α, and patients without comorbidities had higher levels of TNF-α, IL-4 and IL-2 (p<0.05). In contrast, patients over age 60 with comorbidities had higher levels of IL-6. In the post-COVID-19 group, subjects with long COVID-19 had higher levels of IL-17 and IL-2 (p<0.05), and subjects without sequelae had higher levels of IL-10, IL-6 and IL- 4 (p<0.05).

Our results suggest that advanced age, comorbidities and elevated serum IL-6 levels are associated with severe COVID-19 and are good markers to differentiate severe from mild cases. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 and IL-10 appear to constitute a cytokine profile of long COVID-19, and these markers are potential targets for COVID-19 treatment and prevention strategies.

Source: Queiroz MAF, Neves PFMD, Lima SS, Lopes JDC, Torres MKDS, Vallinoto IMVC, Bichara CDA, Dos Santos EF, de Brito MTFM, da Silva ALS, Leite MM, da Costa FP, Viana MNDSA, Rodrigues FBB, de Sarges KML, Cantanhede MHD, da Silva R, Bichara CNC, van den Berg AVS, Veríssimo AOL, Carvalho MDS, Henriques DF, Dos Santos CP, Nunes JAL, Costa IB, Viana GMR, Carneiro FRO, Palacios VRDCM, Quaresma JAS, Brasil-Costa I, Dos Santos EJM, Falcão LFM, Vallinoto ACR. Cytokine Profiles Associated With Acute COVID-19 and Long COVID-19 Syndrome. Front Cell Infect Microbiol. 2022 Jun 30;12:922422. doi: 10.3389/fcimb.2022.922422. PMID: 35846757; PMCID: PMC9279918. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9279918/ (Full text)