A review of intravenous immunoglobulin in the treatment of neuroimmune conditions, acute COVID-19 infection, and post-acute sequelae of COVID-19 Syndrome

Abstract:

Intravenous immunoglobulin (IVIG) is an immunomodulatory therapy that has been studied in several neuroimmune conditions, such as Guillain-Barré Syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and multiple sclerosis. It has also been proposed as a potential treatment option for acute COVID-19 infection and post-acute sequelae of SARS-CoV-2 infection (PASC). IVIG is thought to function by providing the recipient with a pool of antibodies, which can, in turn, modulate immune responses through multiple mechanisms including neutralization of cytokines and autoantibodies, saturation of neonatal fragment crystallizable receptors, inhibition of complement activation, and regulation of T and B cell mediated inflammation.

In acute COVID-19, studies have shown that early administration of IVIG and plasmapheresis in severe cases can reduce the need for mechanical ventilation, shorten ICU and hospital stays, and lower mortality. Similarly, in PASC, while research is still in early stages, IVIG has been shown to alleviate persistent symptoms in small patient cohorts.

Furthermore, IVIG has shown benefits in another condition which has symptomatic overlap with PASC, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), though studies have yielded mixed results. It is important to note that IVIG can be associated with several potential adverse effects, such as anaphylaxis, headaches, thrombosis, liver enzyme elevations and renal complications. In addition, the high cost of IVIG can be a deterrent for payers and patients.

This review provides a comprehensive update on the use of IVIG in multiple neuroimmune conditions, ME/CFS, acute COVID-19, and PASC, as well as covers its history, production, pricing, and mechanisms of action. We also identify key areas of future research, including the need to optimize the use of Ig product dosing, timing, and patient selection across conditions, particularly in the context of COVID-19 and PASC.

Source: Morse BA, Motovilov K, Michael Brode W, Michael Tee F, Melamed E. A review of intravenous immunoglobulin in the treatment of neuroimmune conditions, acute COVID-19 infection, and post-acute sequelae of COVID-19 Syndrome. Brain Behav Immun. 2024 Oct 8:S0889-1591(24)00648-2. doi: 10.1016/j.bbi.2024.10.006. Epub ahead of print. PMID: 39389388. https://www.sciencedirect.com/science/article/abs/pii/S0889159124006482

Inhibition of HIF-2α Pathway as a Potential Therapeutic Strategy for Endothelial Dysfunction in Post-COVID Syndrome

Abstract:

Background SARS-CoV-2 infection may lead to Post-COVID Syndrome (PCS), characterized by debilitating symptoms like persistent fatigue, cardiovascular symptoms, and cognitive dysfunction. Persistent endothelial dysfunction (ED) is a potential driver of ongoing symptoms. Yet, the underlying biological mechanisms remain unclear.

Methods In this prospective observational study, we characterized 41 PCS patients and 24 healthy controls (HC, matched out of n = 204, recruited before the pandemic) and investigated the effect of SARS-CoV-2 Spike protein 1 (S1) and plasma from PCS patients on human retinal endothelial cells (HREC).

Results Plasma samples from PCS patients exhibited significantly elevated erythropoietin, VEGF and MCP-1 alongside decreased IL-6 levels compared to HC. Low Haemoglobin and Haematocrit were negatively associated with PCS severity. VEGF levels were positively correlated with Anti-S1 IgG levels in patients and upregulated on mRNA level in HREC exposed to S1. Additionally, S1 exposure promoted ROS production and transiently activated HIF-1α in HREC. Persistent activation of HIF-2α by S1 led to disrupted endothelial integrity. HREC exposed to plasma from severely affected PCS patients showed increased ROS and compromised barrier function. Treatment with Belzutifan, a HIF-2α inhibitor, restored barrier integrity in HREC exposed to S1 or PCS-plasma.

Conclusion These findings suggest that HIF-2α-mediated ED in PCS might be a potential therapeutical target for Belzutifan.

Trial registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05635552

What Is Known?

  • Endothelial dysfunction (ED) is a consequence of acute SARS-CoV-2 infection and may lead to Post-COVID syndrome (PCS) symptoms.

  • Patients with PCS show elevated inflammation and endothelial dysfunction markers.

  • Spike proteins can persist for up to 12 months post-infection, driving ongoing inflammation and immune activation.

What New Information Does This Article Contribute?

  • Low haemoglobin (Hb) and high VEGF correlate with higher Anti-S1 IgG and low Hb is associated with higher C19-YRS severity score.

  • PCS patients exhibit higher Erythropoietin (EPO) levels when compared to HC.

  • Spike protein 1 (S1) alone and PCS patient’s plasma induce endothelial dysfunction primarily through HIF-2α activation.

  • Both S1 and PCS plasma cause oxidative stress and disrupting endothelial integrity.

  • Inhibition of HIF-2α effectively restores endothelial barrier integrity disrupted by S1 and PCS plasma.

What New Information Does This Article Contribute? Persistent circulation of spike proteins can sustain chronic inflammation and immune activation in patients with PCS. Here we show that plasma from PCS patients exhibits significantly elevated levels of VEGF which positively correlates with Anti-S1 IgG. Low haemoglobin was associated with higher Anti-S1 IgG titres and correlated with a higher C19-YRS severity score. Levels of EPO were higher in PCS patients, with a more pronounced effect observed in patients with cardiovascular symptoms. In human retinal endothelial cells, both S1 and plasma from PCS patients primarily induce ED through HIF-2α activation, rather than NF-κB. Both factors lead to significant oxidative stress, evidenced by increased ROS production which in turn disrupts endothelial barrier integrity and function. Notably, Belzutifan, a HIF-2α inhibitor, can restore this compromised endothelial function, offering a potential therapeutic target for PCS.

Source: Andrea Ribeiro, Timon Kuchler, Maciej Lech, Javier Carbajo-Lozoya, Kristina Adorjan, Hans Christian Stubbe, Martina Seifert, Anna Wöhnle, Veronika Kesseler, Johanna Negele, Uwe Heemann, Christoph Schmaderer. Inhibition of HIF-2α Pathway as a Potential Therapeutic Strategy for Endothelial Dysfunction in Post-COVID Syndrome medRxiv 2024.09.10.24313403; doi: https://doi.org/10.1101/2024.09.10.24313403 https://www.medrxiv.org/content/10.1101/2024.09.10.24313403v1.full-text (Full text)

A multimodal approach for treating post-acute infectious syndrome

Abstract:

Long-term complications, such as extensive fatigue and cognitive issues, are known from various infections, including SARS-CoV-2, influenza
virus, or Borrelia burgdorferi. The pathology is mostly unknown and differs between patients. Unfortunately, there is currently no common and
effective treatment. In this perspective, we imply that post-acute infectious syndromes are due to a variety of factors, including among others
diminished tissue perfusion, tissue infiltration by viruses, inflammation, and oxidative stress, and that not one specific biomarker can be used
to measure these syndromes. Thus, we suggest that a score based on a number of criteria/factors should be used to assess post-acute infectious
syndromes.

Consequently, probably not one single treatment can be used to treat this group of patients, and we suggest a multimodal
treatment regimen comprising a combination of pharmacotherapy, such as metformin and naltrexone with anti-inflammatory effects,
alongside physical therapies such as extracorporeal apheresis and transcutaneous neurotherapy. This combined approach aims to reduce
biomarker levels and enhance cognitive functions. This implies that a reset of the systems can be achieved by a multimodal approach based on a
score for post-acute infectious syndromes.

Source:  Charlotte Steenblock, Nicole Toepfner, Yannick P. Kok, Philip Mavberg, Horst Bruckmoser, Alfons Breu, Johannes Korth, Harald Heidecke, Milo A. Puhan, and Stefan R. Bornstein. A multimodal approach for treating post-acute infectious syndrome. Brain Medicine (2024) 1, 1–7; doi: https://doi.org/10.61373/bm024p.0064; Published online: 30 August 2024. https://bm.genomicpress.com/wp-content/uploads/2024/08/BM0064-Steenblock-2024.pdf (Full text)

Long COVID as a Disease of Accelerated Biological Aging: An Opportunity to Translate Geroscience Interventions

Abstract:

It has been four years since long COVID-the protracted consequences that survivors of COVID-19 face-was first described. Yet, this entity continues to devastate the quality of life of an increasing number of COVID-19 survivors without any approved therapy. Furthermore, there remains a paucity of clinical trials addressing the biological root causes of this disease. Notably, the symptoms of long COVID-including but not limited to exercise intolerance, cognitive impairment, orthostasis, and functional decline-are typically seen with advancing age.

Leveraging this similarity, we posit that Geroscience-which aims to target the biological drivers of aging to prevent age-associated conditions as a group-could offer promising therapeutic avenues for long COVID. Bearing this in mind, this review presents a framework for studying long COVID as a state of effectively accelerated biological aging. Thus, we comprehensively review here the role of biological hallmarks of aging in long COVID, identifying research gaps and proposing directions for future preclinical and clinical studies.

Source: Shafqat A, Masters MC, Tripathi U, Tchkonia T, Kirkland JL, Hashmi SK. Long COVID as a Disease of Accelerated Biological Aging: An Opportunity to Translate Geroscience Interventions. Ageing Res Rev. 2024 Jun 28:102400. doi: 10.1016/j.arr.2024.102400. Epub ahead of print. PMID: 38945306. https://www.sciencedirect.com/science/article/abs/pii/S1568163724002186

Reduction of long COVID symptoms after stellate ganglion block: A retrospective chart review study

Abstract:

The SARS-CoV-2 pandemic has left millions of individuals with a host of post-viral symptoms that can be debilitating and persist indefinitely. To date there are no definitive tests or treatments for the collection of symptoms known as “Long COVID” or Post-acute sequelae of COVID-19 (PASC). Following our initial case report detailing improvement of Long COVID symptoms after sequential bilateral stellate ganglion blockade (SGB), we performed a retrospective chart analysis study on individuals treated with the same protocol over the course of six months (2021-2022) in our clinic.

Patients self-reported symptoms on a 10-point scale as part of optional patient follow-up using an online survey. After one month or more following treatment, patients reported striking reductions in Fatigue, Worsening of Symptoms following Mental and Physical Activity, Memory Problems, Problems Concentrating, Sleep Problems, Anxiety, and Depression. Loss of Taste and Loss of Smell in some individuals did not respond to treatment, likely indicating structural damage following infection.

This study suggests that neuromodulation may provide relief of Long COVID symptoms for at least a subset of individuals, and provides support for prospective studies of this potential treatment.

Source: Duricka D, Liu L. Reduction of long COVID symptoms after stellate ganglion block: A retrospective chart review study. Auton Neurosci. 2024 Jun 13;254:103195. doi: 10.1016/j.autneu.2024.103195. Epub ahead of print. PMID: 38901177. https://www.autonomicneuroscience.com/article/S1566-0702(24)00049-3/fulltext (Full text)

Systems Modeling Reveals Shared Metabolic Dysregulation and Novel Therapeutic Treatments in ME/CFS and Long COVID

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long COVID are complex, multisystemic conditions that pose ongoing challenges to healthcare professionals. Emerging research suggests that ME/CFS and Long COVID exhibit overlapping metabolic symptoms, indicating possible shared metabolic dysfunctions. This study aims to systematically explore these shared metabolic disturbances and their potential treatments.

Utilizing our novel metabolic modeling method, GPMM, we identified the key metabolic irregularities in patients with ME/CFS and Long COVID, notably the downregulation of the alanine and aspartate metabolism pathway, and the arginine and proline metabolism pathway.

Genome-wide knockout analyses indicated that supplementation with aspartate (ASP) or asparagine (ASN) could potentially ameliorate these metabolic deficiencies. Further metabolic assessments in Long COVID patients highlighted the significant downregulation of ASP in both blood and muscle, supporting our predictions.

Consequently, we propose that the combination of l-ornithine and l-aspartate (LOLA) offers a promising approach to alleviate metabolic symptoms in both ME/CFS and Long COVID patients. This study not only elucidates the shared metabolic pathways in ME/CFS and Long COVID but also positions LOLA as a viable candidate for future clinical trials.

Source: Gong-Hua LiFeifei HanQing-Peng KongWenzhong Xiao. Systems Modeling Reveals Shared Metabolic Dysregulation and Novel Therapeutic Treatments in ME/CFS and Long COVID.

Longitudinal Progression of Patients with Long COVID Treated in a Post-COVID Clinic: A Cross-Sectional Survey

Abstract:

Background: In addition to the morbidity and mortality associated with acute infection, COVID-19 has been associated with persistent symptoms (>30 days), often referred to as Long COVID (LC). LC symptoms often cluster into phenotypes, resembling conditions such as fibromyalgia, postural orthostatic tachycardiac syndrome (POTS), and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). LC clinics have been established to best address the needs of LC patients and continuity of care. We developed a cross-sectional survey to assess treatment response through our LC Clinic (LCC).

Methods: A 25-question survey (1-10 Likert scale) was expert- and content-validated by LCC clinicians, patients, and patient advocates. The survey assessed LC symptoms and the helpfulness of different interventions, including medications and supplements. A total of 852 LCC patients were asked to complete the survey, with 536 (62.9%) responding.

Results: The mean time from associated COVID-19 infection to survey completion was 23.2 ± 6.4 months. The mean age of responders was 52.3 ± 14.1 (63% females). Self-reported symptoms were all significantly improved (P < .001) from the initial visit to the LCC (baseline) to the time of the follow-up survey. However, only 4.5% (24/536) of patients rated all symptoms low (1-2) at the time of the survey, indicating low levels of full recovery in our cohort. The patients rated numerous interventions as being helpful, including low-dose naltrexone (45/77; 58%), vagal nerve stimulation (18/34; 53%), and fisetin (28/44; 64%).

Conclusions: Patients report general improvements in symptoms following the initial LCC visit, but complete recovery rates remain low at 23.2 ± 6.4 months.

Source: Hurt RT, Yadav S, Schroeder DR, Croghan IT, Mueller MR, Grach SL, Aakre CA, Gilman EA, Stephenson CR, Overgaard J, Collins NM, Lawson DK, Thompson AM, Natividad LT, Mohamed Elfadil O, Ganesh R. Longitudinal Progression of Patients with Long COVID Treated in a Post-COVID Clinic: A Cross-Sectional Survey. J Prim Care Community Health. 2024 Jan-Dec;15:21501319241258671. doi: 10.1177/21501319241258671. PMID: 38813984. https://journals.sagepub.com/doi/10.1177/21501319241258671 (Full text)

The Role of Heparin in Postural Orthostatic Tachycardia Syndrome and Other Post-Acute Sequelae of COVID-19

Abstract:

The therapeutic management and short-term consequences of the coronavirus disease 2019 (COVID-19) are well known. However, COVID-19 post-acute sequelae are less known and represent a public health problem worldwide. Patients with COVID-19 who present post-acute sequelae may display immune dysregulation, a procoagulant state, and persistent microvascular endotheliopathy that could trigger microvascular thrombosis. These elements have also been implicated in the physiopathology of postural orthostatic tachycardia syndrome, a frequent sequela in post-COVID-19 patients.
These mechanisms, directly associated with post-acute sequelae, might determine the thrombotic consequences of COVID-19 and the need for early anticoagulation therapy. In this context, heparin has several potential benefits, including immunomodulatory, anticoagulant, antiviral, pro-endothelial, and vascular effects, that could be helpful in the treatment of COVID-19 post-acute sequelae. In this article, we review the evidence surrounding the post-acute sequelae of COVID-19 and the potential benefits of the use of heparin, with a special focus on the treatment of postural orthostatic tachycardia syndrome.

Source: Gómez-Moyano E, Pavón-Morón J, Rodríguez-Capitán J, Bardán-Rebollar D, Ramos-Carrera T, Villalobos-Sánchez A, Pérez de Pedro I, Ruiz-García FJ, Mora-Robles J, López-Sampalo A, et al. The Role of Heparin in Postural Orthostatic Tachycardia Syndrome and Other Post-Acute Sequelae of COVID-19. Journal of Clinical Medicine. 2024; 13(8):2405. https://doi.org/10.3390/jcm13082405 https://www.mdpi.com/2077-0383/13/8/2405 (Full text)

A Narrative Review on Gut Microbiome Disturbances and Microbial Preparations in ME/CFS: Implications for Long COVID

Abstract:

Myalgic Encephalomyelitis, also known as Chronic Fatigue Syndrome (ME/CFS) and Long COVID are characterized by debilitating post-exertional malaise and other core symptoms related to immune dysregulation resultant from post-viral infection, including mitochondrial dysfunction, chronic neuroinflammation and gut dysbiosis. The reported associations between altered microbiota composition and cardinal symptoms of ME/CFS and Long COVID, suggesting that use of microbial preparations, such as probiotics, by restoring the homeostasis of the brain-immune-gut axis may help in the management of symptoms in both conditions.

Therefore, this review aims to investigate the implications of alerted gut microbiome and assess the evidence supporting use of microbial-based preparations, including probiotics, synbiotics, postbiotics alone and/or in combination with other nutraceuticals in the management of fatigue, inflammation, as well as neuropsychiatric and gastrointestinal symptoms among patients with ME/CFS and Long COVID.

Source: Jurek, J.M.; Castro-Marrero, J. A Narrative Review on Gut Microbiome Disturbances and Microbial Preparations in ME/CFS: Implications for Long COVID. Preprints 2024, 2024042021. https://doi.org/10.20944/preprints202404.2021.v1  https://www.preprints.org/manuscript/202404.2021/v1 (Full text available as PDF file)

Investigation into the restoration of TRPM3 ion channel activity in post-COVID-19 condition: a potential pharmacotherapeutic target

Abstract:

Introduction: Recently, we reported that post COVID-19 condition patients also have Transient Receptor Potential Melastatin 3 (TRPM3) ion channel dysfunction, a potential biomarker reported in natural killer (NK) cells from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients. As there is no universal treatment for post COVID-19 condition, knowledge of ME/CFS may provide advances to investigate therapeutic targets. Naltrexone hydrochloride (NTX) has been demonstrated to be beneficial as a pharmacological intervention for ME/CFS patients and experimental investigations have shown NTX restored TRPM3 function in NK cells. This research aimed to: i) validate impaired TRPM3 ion channel function in post COVID-19 condition patients compared with ME/CFS; and ii) investigate NTX effects on TRPM3 ion channel activity in post COVID-19 condition patients.

Methods: Whole-cell patch-clamp was performed to characterize TRPM3 ion channel activity in freshly isolated NK cells of post COVID-19 condition (N = 9; 40.56 ± 11.26 years), ME/CFS (N = 9; 39.33 ± 9.80 years) and healthy controls (HC) (N = 9; 45.22 ± 9.67 years). NTX effects were assessed on post COVID-19 condition (N = 9; 40.56 ± 11.26 years) and HC (N = 7; 45.43 ± 10.50 years) where NK cells were incubated for 24 hours in two protocols: treated with 200 µM NTX, or non-treated; TRPM3 channel function was assessed with patch-clamp protocol.

Results: This investigation confirmed impaired TRPM3 ion channel function in NK cells from post COVID-19 condition and ME/CFS patients. Importantly, PregS-induced TRPM3 currents were significantly restored in NTX-treated NK cells from post COVID-19 condition compared with HC. Furthermore, the sensitivity of NK cells to ononetin was not significantly different between post COVID-19 condition and HC after treatment with NTX.

Discussion: Our findings provide further evidence identifying similarities of TRPM3 ion channel dysfunction between ME/CFS and post COVID-19 condition patients. This study also reports, for the first time, TRPM3 ion channel activity was restored in NK cells isolated from post COVID-19 condition patients after in vitro treatment with NTX. The TRPM3 restoration consequently may re-establish TRPM3-dependent calcium (Ca2+) influx. This investigation proposes NTX as a potential therapeutic intervention and TRPM3 as a treatment biomarker for post COVID-19 condition.

Source: Etianne Martini Sasso, Katsuhiko Muraki, Natalie Eaton-Fitch, Peter Smith, Andrew Jeremijenko, Paul Griffin, Sonya Marshall-Gradisnik. Investigation into the restoration of TRPM3 ion channel activity in post-COVID-19 condition: a potential pharmacotherapeutic target. Front. Immunol., 02 May 2024; Sec. Multiple Sclerosis and Neuroimmunology; Volume 15 – 2024 | https://doi.org/10.3389/fimmu.2024.1264702. https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1264702/full (Full text)