Tag: long covid etiology

Lots of long COVID treatment leads, but few are proven

As the current crisis phase of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic winds down—and the world nervously awaits potentially dangerous new variants—research into the nature and treatment of so-called long coronavirus disease (COVID) is beginning to ramp up. The White House has promised funding and a federal research roadmap, and dedicated clinics have started cropping up at academic medical centers across the country.

But attempts to understand and treat long COVID have been underway almost since the pandemic began. For more than 2 years, clinicians have been coping—mostly on their own—with streams of patients complaining of persistent symptoms or mysterious new ones after a bout with COVID-19 had seemingly resolved ( 1 ). And collectively, doctors and researchers have already made headway toward identifying some of the mechanisms underlying the condition—formally known as post-acute sequelae of COVID (PASC).

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Source: Leah Shaffer. Lots of long COVID treatment leads, but few are proven. Vol. 119 | No. 36. https://www.pnas.org/doi/10.1073/pnas.2213524119 (Full text)

Post COVID syndrome: A novel challenge and threat to international health

Abstract:

The global pandemic caused by the SARS-CoV-2 virus has affected every continent worldwide. The novelty of this virus, its mutations and the rapid speed and unprecedented rate at which it has torn through the global community has in turn lead to an innate lack of knowledge and information about the actual disease caused and the severity of the complications associated with COVID-19.

The SARS-CoV-2 virus has been infecting individuals since 2019 and now as of 2022 has been circulating for just over 2 years within the global populous. As the number of cases have risen globally over this period (some of which having contracted the virus twice) further endeavours have been undertaken to better understand the pathogenesis and natural progression of the disease. A condition reported in some cases with extended bouts of sickness or symptoms following the initial infection with COVID was labelled “long COVID” towards the earlier phases of the pandemic (in the spring of 2020), but has only recently gained the global media and medical attention due to its affliction of more individuals on a global basis and has thus warranted further investigation.

Long COVID is described as a persistent, long-term state of poor health following an infection with COVID-19. The effect of Long COVID is multisystemic in nature with a wide array of signs and symptoms. The most commonly reported clinical features of long COVID are: headaches, myalgia, chest pain, rashes, abdominal pain, shortness of breath, palpitations, anosmia, persistent cough, brain fogs, forgetfulness, depression, insomnia, fatigue and anxiety. This research aims to explore the symptomatology, pathophysiology as well as the treatment and prevention of Long COVID.

Source: Banerjee I, Robinson J, Leclézio A, Sathian B, Banerjee I. Post COVID syndrome: A novel challenge and threat to international health. Nepal J Epidemiol. 2022 Jun 30;12(2):1215-1219. doi: 10.3126/nje.v12i2.46149. PMID: 35974973; PMCID: PMC9374107.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9374107/ (Full text)

COVID-19 and Therapeutic Apheresis

Abstract:

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, is an unprecedented challenge for the global community. The pathogenesis of COVID-19, its complications and long term sequelae (so called Long/Post-COVID) include, in addition to the direct virus-induced tissues injury, multiple secondary processes, such as autoimmune response, impairment of microcirculation, and hyperinflammation. Similar pathological processes, but in the settings of neurological, cardiovascular, rheumatological, nephrological, and dermatological diseases can be successfully treated by powerful methods of Therapeutic Apheresis (TA).

We describe here the rationale and the initial attempts of TA treatment in severe cases of acute COVID-19. We next review the evidence for the role of autoimmunity, microcirculatory changes and inflammation in pathogenesis of Long/Post COVID and the rationale for targeting those pathogenic processes by different methods of TA. Finally, we discuss the impact of COVID-19 pandemic on patients, who undergo regular TA treatments due to their underlying chronic conditions, with the specific focus on the patients with inherited lipid diseases being treated at the Dresden University Apheresis Center.

Source: Tselmin S, Julius U, Jarzebska N, Rodionov R. COVID-19 and Therapeutic Apheresis. Horm Metab Res. 2022 Aug;54(8):571-577. doi: 10.1055/a-1864-9482. Epub 2022 Aug 9. PMID: 35944525.  https://pubmed.ncbi.nlm.nih.gov/35944525/

Mast cell activation syndrome and the link with long COVID

Abstract:

Mast cells are innate immune cells found in connective tissues throughout the body, most prevalent at tissue-environment interfaces. They possess multiple cell-surface receptors which react to various stimuli and, after activation, release many mediators including histamine, heparin, cytokines, prostaglandins, leukotrienes and proteases.

In mast cell activation syndrome, excessive amounts of inflammatory mediators are released in response to triggers such as foods, fragrances, stress, exercise, medications or temperature changes. Diagnostic markers may be difficult to assess because of their rapid degradation; these include urinary N-methyl histamine, urinary prostaglandins D2, DM and F2α and serum tryptase (which is stable) in the UK. Self-management techniques, medications and avoiding triggers may improve quality of life. Treatments include mast cell mediator blockers, mast cell stabilisers and anti-inflammatory agents. ‘Long COVID’ describes post-COVID-19 syndrome when symptoms persist for more than 12 weeks after initial infection with no alternative diagnosis.

Both mast cell activation syndrome and long COVID cause multiple symptoms. It is theorised that COVID-19 infection could lead to exaggeration of existing undiagnosed mast cell activation syndrome, or could activate normal mast cells owing to the persistence of viral particles. Other similarities include the relapse-remission cycle and improvements with similar treatments. Importantly, however, aside from mast cell disorders, long COVID could potentially be attributed to several other conditions.

Source: Arun S, Storan A, Myers B. Mast cell activation syndrome and the link with long COVID. Br J Hosp Med (Lond). 2022 Jul 2;83(7):1-10. doi: 10.12968/hmed.2022.0123. Epub 2022 Jul 26. PMID: 35938771. https://pubmed.ncbi.nlm.nih.gov/35938771/

Prevalence of symptoms, comorbidities, fibrin amyloid microclots and platelet pathology in individuals with Long COVID/Post-Acute Sequelae of COVID-19 (PASC)

Abstract:

Background: Fibrin(ogen) amyloid microclots and platelet hyperactivation previously reported as a novel finding in South African patients with the coronavirus 2019 disease (COVID-19) and Long COVID/Post-Acute Sequelae of COVID-19 (PASC), might form a suitable set of foci for the clinical treatment of the symptoms of Long COVID/PASC. A Long COVID/PASC Registry was subsequently established as an online platform where patients can report Long COVID/PASC symptoms and previous comorbidities.

Methods: In this study, we report on the comorbidities and persistent symptoms, using data obtained from 845 South African Long COVID/PASC patients. By using a previously published scoring system for fibrin amyloid microclots and platelet pathology, we also analysed blood samples from 80 patients, and report the presence of significant fibrin amyloid microclots and platelet pathology in all cases.

Results: Hypertension, high cholesterol levels (dyslipidaemia), cardiovascular disease and type 2 diabetes mellitus (T2DM) were found to be the most important comorbidities. The gender balance (70% female) and the most commonly reported Long COVID/PASC symptoms (fatigue, brain fog, loss of concentration and forgetfulness, shortness of breath, as well as joint and muscle pains) were comparable to those reported elsewhere. These findings confirmed that our sample was not atypical. Microclot and platelet pathologies were associated with Long COVID/PASC symptoms that persisted after the recovery from acute COVID-19.

Conclusions: Fibrin amyloid microclots that block capillaries and inhibit the transport of O2 to tissues, accompanied by platelet hyperactivation, provide a ready explanation for the symptoms of Long COVID/PASC. Removal and reversal of these underlying endotheliopathies provide an important treatment option that urgently warrants controlled clinical studies to determine efficacy in patients with a diversity of comorbidities impacting on SARS-CoV-2 infection and COVID-19 severity. We suggest that our platelet and clotting grading system provides a simple and cost-effective diagnostic method for early detection of Long COVID/PASC as a major determinant of effective treatment, including those focusing on reducing clot burden and platelet hyperactivation.

Source: Pretorius E, Venter C, Laubscher GJ, Kotze MJ, Oladejo SO, Watson LR, Rajaratnam K, Watson BW, Kell DB. Prevalence of symptoms, comorbidities, fibrin amyloid microclots and platelet pathology in individuals with Long COVID/Post-Acute Sequelae of COVID-19 (PASC). Cardiovasc Diabetol. 2022 Aug 6;21(1):148. doi: 10.1186/s12933-022-01579-5. PMID: 35933347; PMCID: PMC9356426. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9356426/ (Full text)

COVID-19 May Be a Trigger for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

ALBANY, N.Y. (July 25, 2022) – UAlbany researcher Roxana Moslehi from the Department of Epidemiology and Biostatistics is conducting important investigations on myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to better understand the illness, including its potential connection to cancer, auto-immune disease, and long-haul COVID-19.

According to the CDC, 1 in thirteen adults in the U.S. have COVID-19 symptoms lasting three or more months after contracting the virus—a condition often referred to as “long COVID.” However, research suggests that long COVID is complex, and in some instances may not be COVID-19 at all, but rather ME/CFS—triggered by COVID-19.

ME/CFS is a complex disabling disorder with no known treatment. Between 25 and 50 percent of those with the illness are bed or housebound for extended periods of time, with overwhelming fatigue that does not diminish after resting and difficulty performing daily tasks. Prior to the COVID-19 pandemic, it was estimated that up to 3.4 million people in the US suffered from the illness—the range is large due to the difficulty in diagnosing the disease as it is often dismissed or assumed to be another disorder.

Since ME/CFS is believed to be triggered by the onset of an infectious illness, research suggests that COVID-19 may be a trigger for ME/CFS. The chronic long-haul COVID-19 symptoms that some people report as following the resolution of their acute illness have similarities to symptoms of ME/CFS, such as persistent fatigue, sleep dysfunction, cognitive impairment, impaired memory, and more.

“It is estimated that in the wake of the COVID-19 pandemic, more than 10 million new ME/CFS cases may be triggered around the world,” Moslehi explains. “This makes it urgent to identify risk factors and underlying biologic mechanisms for this condition along with its potential connection to COVID-19.”

Moslehi conducted a molecular epidemiologic investigation of ME/CFS (funded by an NIH research grant awarded to her) to better understand the illness, providing the most compelling evidence to date that ME/CFS may be an auto-immune disorder. She compared people who developed ME/CFS after having an infectious illness with a group of individuals without ME/CFS (called the control group). She looked at various intrinsic factors related to the participants’ health, such as personal history of allergy and asthma, and extrinsic or environmental factors such as exposure to contaminants. She also assessed the prevalence of illnesses such as auto-immune diseases and cancer in their families, levels of serum immune system markers such as cytokines, and molecular evidence of viral reactivation such as mono flare-ups.

The study, published in the proceedings of the American Society of Human Genetics (ASHG), the International Genetic Epidemiology Society (IGES) and the American Association for Cancer Research (AACR), found that those with ME/CFS were five times more likely to have a family history of auto-immune diseases than the control group. ME/CFS was also associated with an increased risk of early-onset cancer (diagnosed before 60 years old) among the first-degree relatives. ME/CFS was associated with certain risk factors such as a history of allergies requiring medication and exposure to contaminants. The analysis by the Moslehi lab also identified a panel of cytokines that predict the risk of ME/CFS with high accuracy. A couple of the identified cytokines are involved in inflammatory processes and have been linked to other auto-immune diseases.

“Our multidimensional analysis of pedigree, epidemiologic, and molecular data not only provides the most objective evidence to date that ME/CFS may be an auto-immune disease— it provides etiologic clues and leads for prevention” says Moslehi. “In addition, our results may enable defining a subset of COVID-19 patients, who are at risk of developing long COVID or ME/CFS, for targeted monitoring and/or therapy.”

More recently, Moslehi, in collaboration with her colleagues at the NIH, obtained two additional NIH (intramural) grants to continue her research on ME/CFS. Through these grants, the DNA and RNA of ME/CFS cases and controls have been sequenced and will be analyzed to identify genes and genetic variations that are associated with ME/CFS.

“The ultimate goal is to conduct an integrative analysis of multi-omics (genomics, proteomics, transcriptomics) data to gain deeper insight into the biologic mechanisms of ME/CFS and identify druggable targets for ME/CFS therapy,” she says.

 

Cardiometabolic syndrome — an emergent feature of Long COVID?

Large-scale clinical studies on the post-infectious impacts of SARS-CoV-2 have suggested that patients who have recovered from acute infection have increased risk for cardiometabolic syndrome-associated morbidities such as diabetes, chronic kidney disease and heart failure. Initial studies have taken the first steps towards unravelling the molecular processes that may be driving these findings, including the role of immune and inflammatory factors, but a comprehensive aetiology remains unclear. Given that cardiometabolic syndrome progression in patients with Long COVID may pose a significant global health and economic burden post pandemic, there is an emergent need to identify therapeutic targets and treatment options.

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Source: Frere, J.J., tenOever, B.R. Cardiometabolic syndrome — an emergent feature of Long COVID?. Nat Rev Immunol (2022). https://doi.org/10.1038/s41577-022-00739-8 (Full text)

Autoantibodies against apolipoprotein A-1 after COVID-19 predict symptoms persistence

Abstract:

Background: SARS-CoV-2 infection triggers different auto-antibodies, including anti-apolipoprotein A-1 IgGs (AAA1), which could be of concern as mediators of persistent symptoms. We determined the kinetics of AAA1 response over after COVID-19, and the impact of AAA1 on the inflammatory response and symptoms persistence.

Methods: All serologies were assessed at one, three, six, and twelve months in 193 hospital employees with COVID-19. ROC curve analyses and logistic regression models (LRM) were used to determine the prognostic accuracy of AAA1 and their association with patient-reported COVID-19 symptoms persistence at 12 months. Interferon (IFN)-α and-γ production by AAA1-stimulated human monocyte-derived macrophages (HMDM) was assessed in vitro.

Results: AAA1 seropositivity was 93% at one month and declined to 15% at 12 months after COVID-19. Persistent symptoms at 12 months were observed in 45.1% of participants, with a predominance of neurological (28.5%), followed by general (15%) and respiratory symptoms (9.3%). Over time, strength of correlations between AAA1 and anti-SARS-COV2 serologies decreased, but remained significant. From the 3rd month on, AAA1 levels predicted persistent respiratory symptoms (area under the curves 0.72-0.74; p<0.001), independently of disease severity, age and gender (adjusted odds ratios 4.81-4.94; p=0.02), while anti-SARS-CoV-2 serologies did not. AAA1 increased IFN-α production by HMDMs (p=0.03), without affecting the IFN-γ response.

Conclusion: COVID-19 induces a marked though transient AAA1 response, independently predicting one-year persistence of respiratory symptoms. By increasing IFN-α response, AAA1 may contribute to persistent symptoms. If and how AAA1 levels assessment could be of use for COVID-19 risk stratification remains to be determined

Source: L’Huillier AG, Pagano S, Baggio S, Meyer B, Andrey DO, Nehme M, Guessous I, Eberhardt CS, Huttner A, Posfay-Barbe KM, Yerly S, Siegrist CA, Kaiser L, Vuilleumier N. Autoantibodies against apolipoprotein A-1 after COVID-19 predict symptoms persistence. Eur J Clin Invest. 2022 May 22:e13818. doi: 10.1111/eci.13818. Epub ahead of print. PMID: 35598178.  https://pubmed.ncbi.nlm.nih.gov/35598178/ (Full text available as PDF file)

Impaired exercise capacity in post-COVID syndrome: the role of VWF-ADAMTS13 axis

Abstract:

Post-COVID syndrome (PCS) or Long-COVID is an increasingly recognised complication of acute SARS-CoV-2 infection, characterised by persistent fatigue, reduced exercise tolerance chest pain, shortness of breath and cognitive slowing. Acute COVID-19 is strongly linked with increased risk of thrombosis; a prothrombotic state, quantified by elevated Von Willebrand Factor (VWF) Antigen (Ag):ADAMTS13 ratio, and is associated with severity of acute COVID-19 infection. We investigated if patients with PCS also had evidence of a pro-thrombotic state associating with symptom severity.

In a large cohort of patients referred to a dedicated post-COVID-19 clinic, thrombotic risk including VWF(Ag):ADAMTS13 ratio, was investigated. An elevated VWF(Ag):ADAMTS13 ratio (≥1.5) was raised in nearly one-third of the cohort and four times more likely in patients with impaired exercise capacity as evidenced by desaturation ≥3% and/or rise in lactate level more than 1 from baseline on 1-minute sit to stand test and/or 6-minute walk test (p<0.0001). 20% (56/276) had impaired exercise capacity, of which 55% (31/56) had a raised VWF(Ag):ADAMTS13 ratio ≥1.5 (p<0.0001). FVIII and VWF(Ag) were elevated in 26% and 18% respectively and support a hypercoagulable state in some patients with PCS.

These findings suggest possible ongoing microvascular/endothelial dysfunction in the pathogenesis of PCS and highlight a potential role for antithrombotic therapy in the management of these patients.

Source: Prasannan N, Heightman M, Hillman T, Wall E, Bell R, Kessler A, Neave L, Doyle AJ, Devaraj A, Singh D, Dehbi HM, Scully M. Impaired exercise capacity in post-COVID syndrome: the role of VWF-ADAMTS13 axis. Blood Adv. 2022 May 11:bloodadvances.2021006944. doi: 10.1182/bloodadvances.2021006944. Epub ahead of print. PMID: 35543533; PMCID: PMC9098525. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9098525/ (Full text)

Obesity and lipid metabolism disorders determine the risk for development of long COVID syndrome: a cross-sectional study from 50,402 COVID-19 patients

Abstract:

Purpose: Metabolic disorders have been identified as major risk factors for severe acute courses of COVID-19. With decreasing numbers of infections in many countries, the long COVID syndrome (LCS) represents the next major challenge in pandemic management, warranting the precise definition of risk factors for LCS development.

Methods: We identified 50,402 COVID-19 patients in the Disease Analyzer database (IQVIA) featuring data from 1056 general practices in Germany. Multivariate logistic regression analysis was used to identify risk factors for the development of LCS.

Results: Of the 50,402 COVID-19 patients included into this analysis, 1,708 (3.4%) were diagnosed with LCS. In a multivariate regression analysis, we identified lipid metabolism disorders (OR 1.46, 95% CI 1.28-1.65, p < 0.001) and obesity (OR 1.25, 95% CI 1.08-1.44, p = 0.003) as strong risk factors for the development of LCS. Besides these metabolic factors, patients’ age between 46 and 60 years (compared to age ≤ 30, (OR 1.81 95% CI 1.54-2.13, p < 0.001), female sex (OR 1.33, 95% CI 1.20-1.47, p < 0.001) as well as pre-existing asthma (OR 1.67, 95% CI 1.39-2.00, p < 0.001) and depression (OR 1.27, 95% CI 1.09-1.47, p = < 0.002) in women, and cancer (OR 1.4, 95% CI 1.09-1.95, p = < 0.012) in men were associated with an increased likelihood of developing LCS.

Conclusion: Lipid metabolism disorders and obesity represent age-independent risk factors for the development of LCS, suggesting that metabolic alterations determine the risk for unfavorable disease courses along all phases of COVID-19.

Source: Loosen SH, Jensen BO, Tanislav C, Luedde T, Roderburg C, Kostev K. Obesity and lipid metabolism disorders determine the risk for development of long COVID syndrome: a cross-sectional study from 50,402 COVID-19 patients. Infection. 2022 Mar 30:1–6. doi: 10.1007/s15010-022-01784-0. Epub ahead of print. PMID: 35355237; PMCID: PMC8966865. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8966865/ (Full text)