Tag: long covid pathophysiology

Dysregulated platelet function in patients with postacute sequelae of COVID-19

Abstract:

Background: Postacute sequelae of COVID-19 (PASC), also referred to as “Long COVID”, sometimes follows COVID-19, a disease caused by SARS-CoV-2. Although SARS-CoV-2 is well known to promote a prothrombotic state, less is known about the thrombosis risk in PASC. Our objective was to evaluate platelet function and thrombotic potential in patients following recovery from SARS-CoV-2, but with clear symptoms of patients with PASC.

Methods: patients with PASC and matched healthy controls were enrolled in the study on average 15 months after documented SARS-CoV-2 infection. Platelet activation was evaluated by light transmission aggregometry (LTA) and flow cytometry in response to platelet surface receptor agonists. Thrombosis in platelet-deplete plasma was evaluated by Factor Xa activity. A microfluidics system assessed thrombosis in whole blood under shear stress conditions.

Results: A mild increase in platelet aggregation in patients with PASC through the thromboxane receptor was observed, and platelet activation through the glycoprotein VI (GPVI) receptor was decreased in patients with PASC compared to age- and sex-matched healthy controls. Thrombosis under shear conditions as well as Factor Xa activity were reduced in patients with PASC. Plasma from patients with PASC was an extremely potent activator of washed, healthy platelets – a phenomenon not observed when stimulating healthy platelets after incubation with plasma from healthy individuals.

Conclusions: patients with PASC show dysregulated responses in platelets and coagulation in plasma, likely caused by a circulating molecule that promotes thrombosis. A hitherto undescribed protective response appears to exist in patients with PASC to counterbalance ongoing thrombosis that is common to SARS-CoV-2 infection.

Source: Aggarwal A, Singh TK, Pham M, Godwin M, Chen R, McIntyre TM, Scalise A, Chung MK, Jennings C, Ali M, Park H, Englund K, Khorana AA, Svensson LG, Kapadia S, McCrae KR, Cameron SJ. Dysregulated platelet function in patients with postacute sequelae of COVID-19. Vasc Med. 2024 Feb 9:1358863X231224383. doi: 10.1177/1358863X231224383. Epub ahead of print. PMID: 38334067. https://pubmed.ncbi.nlm.nih.gov/38334067/

Blood–brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment

Abstract:

Vascular disruption has been implicated in coronavirus disease 2019 (COVID-19) pathogenesis and may predispose to the neurological sequelae associated with long COVID, yet it is unclear how blood–brain barrier (BBB) function is affected in these conditions. Here we show that BBB disruption is evident during acute infection and in patients with long COVID with cognitive impairment, commonly referred to as brain fog. Using dynamic contrast-enhanced magnetic resonance imaging, we show BBB disruption in patients with long COVID-associated brain fog.

Transcriptomic analysis of peripheral blood mononuclear cells revealed dysregulation of the coagulation system and a dampened adaptive immune response in individuals with brain fog. Accordingly, peripheral blood mononuclear cells showed increased adhesion to human brain endothelial cells in vitro, while exposure of brain endothelial cells to serum from patients with long COVID induced expression of inflammatory markers. Together, our data suggest that sustained systemic inflammation and persistent localized BBB dysfunction is a key feature of long COVID-associated brain fog.

Source: Greene, C., Connolly, R., Brennan, D. et al. Blood–brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment. Nat Neurosci (2024). https://doi.org/10.1038/s41593-024-01576-9 https://www.nature.com/articles/s41593-024-01576-9 (Full text)

The Microbiota in Long COVID

Abstract:

Interest in the coronavirus disease 2019 (COVID-19) has progressively decreased lately, mainly due to the great effectivity of vaccines. Furthermore, no new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants able to circumvent the protection of these vaccines, while presenting high transmissibility and/or lethality, have appeared. However, long COVID has emerged as a huge threat to human health and economy globally.
The human microbiota plays an important role in health and disease, participating in the modulation of innate and adaptive immune responses. Thus, multiple studies have found that the nasopharyngeal microbiota is altered in COVID-19 patients, with these changes associated with the onset and/or severity of the disease.
Nevertheless, although dysbiosis has also been reported in long COVID patients, mainly in the gut, little is known about the possible involvement of the microbiota in the development of this disease. Therefore, in this work, we aim to fill this gap in the knowledge by discussing and comparing the most relevant studies that have been published in this field up to this point.
Hence, we discuss that the relevance of long COVID has probably been underestimated, and that the available data suggest that the microbiota could be playing a pivotal role on the pathogenesis of the disease. Further research to elucidate the involvement of the microbiota in long COVID will be essential to explore new therapeutic strategies based on manipulation of the microbiota.
Source: Álvarez-Santacruz C, Tyrkalska SD, Candel S. The Microbiota in Long COVID. International Journal of Molecular Sciences. 2024; 25(2):1330. https://doi.org/10.3390/ijms25021330 https://www.mdpi.com/1422-0067/25/2/1330 (Full text)

Gut Microbiome Composition and Dynamics in Hospitalized COVID-19 Patients and Patients with Post-Acute COVID-19 Syndrome

Abstract:

The gut microbiome plays a pivotal role in the modulation of host responses during viral infections, and recent studies have underscored its significance in the context of coronavirus disease 2019 (COVID-19). We aimed to investigate the dynamics and compositional changes in the gut microbiome of COVID-19 patients, addressing both the acute phase and the recovery process, with a particular focus on the emergence of post-COVID-19 conditions.
Involving 146 COVID-19 patients and 110 healthy controls, this study employed a shotgun metagenomics approach for cross-sectional and longitudinal analyses with one- and three-month follow-ups. We observed a decline in taxonomic diversity among hospitalized COVID-19 patients compared to healthy controls, while a subsequent increase in alpha diversity was shown during the recovery process.
A notable contribution of Enterococcus faecium was identified in the acute phase of the infection, accompanied by an increasing abundance of butyrate-producing bacteria (e.g., Roseburia, Lachnospiraceae_unclassified) during the recovery period. We highlighted a protective role of the Prevotella genus in the long-term recovery process and suggested a potential significance of population-specificity in the early gut microbiome markers of post-acute COVID-19 syndrome.
Our study represents distinctive gut microbiome signatures in COVID-19, with potential diagnostic and prognostic implications, pinpointing potential modulators of the disease progression.
Source: Brīvība M, Silamiķele L, Birzniece L, Ansone L, Megnis K, Silamiķelis I, Pelcmane L, Borisova D, Rozenberga M, Jagare L, et al. Gut Microbiome Composition and Dynamics in Hospitalized COVID-19 Patients and Patients with Post-Acute COVID-19 Syndrome. International Journal of Molecular Sciences. 2024; 25(1):567. https://doi.org/10.3390/ijms25010567 https://www.mdpi.com/1422-0067/25/1/567 (Full text)

New Alcohol Sensitivity in Patients With Post-acute Sequelae of SARS-CoV-2 (PASC): A Case Series

Abstract:

Post-acute sequelae of SARS-CoV-2 (PASC), or long COVID, is characterized by persistent symptoms after acute SARS-CoV-2 infection that can vary from patient to patient. Here, we present a case series of four patients with a history of SARS-CoV-2 infection referred to the Post-Acute COVID-19 Syndrome (PACS) Clinic at Stanford University for evaluation of persistent symptoms, who also experienced new-onset alcohol sensitivity.

Alcohol reactions and sensitivity are not well characterized in the literature as it relates to post-viral illness. While there have been some anecdotal reports of new alcohol sensitivity in PASC patients in the media, there is a paucity of published data in the medical literature about this topic. During their medical consultation, the patients self-reported new changes in their symptoms or behaviors following the use of alcohol. A new onset of alcohol sensitivities should be assessed along with other post-COVID-19 symptoms and may provide novel avenues to explore the pathobiology of illness and potential interventions.

Source: Eastin E F, Tiwari A, Quach T C, et al. (December 29, 2023) New Alcohol Sensitivity in Patients With Post-acute Sequelae of SARS-CoV-2 (PASC): A Case Series. Cureus 15(12): e51286. doi:10.7759/cureus.51286 https://www.cureus.com/articles/152512-new-alcohol-sensitivity-in-patients-with-post-acute-sequelae-of-sars-cov-2-pasc-a-case-series#!/ (Full text)

Muscle abnormalities worsen after post-exertional malaise in long COVID

Abstract:

A subgroup of patients infected with SARS-CoV-2 remain symptomatic over three months after infection. A distinctive symptom of patients with long COVID is post-exertional malaise, which is associated with a worsening of fatigue- and pain-related symptoms after acute mental or physical exercise, but its underlying pathophysiology is unclear.

With this longitudinal case-control study (NCT05225688), we provide new insights into the pathophysiology of post-exertional malaise in patients with long COVID. We show that skeletal muscle structure is associated with a lower exercise capacity in patients, and local and systemic metabolic disturbances, severe exercise-induced myopathy and tissue infiltration of amyloid-containing deposits in skeletal muscles of patients with long COVID worsen after induction of post-exertional malaise. This study highlights novel pathways that help to understand the pathophysiology of post-exertional malaise in patients suffering from long COVID and other post-infectious diseases.

Source: Appelman, B., Charlton, B.T., Goulding, R.P. et al. Muscle abnormalities worsen after post-exertional malaise in long COVID. Nat Commun 15, 17 (2024). https://doi.org/10.1038/s41467-023-44432-3 https://www.nature.com/articles/s41467-023-44432-3 (Full text)

Persisting Shadows: Unraveling the Impact of Long COVID-19 on Respiratory, Cardiovascular, and Nervous Systems

Abstract:

The coronavirus disease 2019 (COVID-19), instigated by the zoonotic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), rapidly transformed from an outbreak in Wuhan, China, into a widespread global pandemic. A significant post-infection condition, known as ‘long- COVID-19′ (or simply ‘long- COVID’), emerges in a substantial subset of patients, manifesting with a constellation of over 200 reported symptoms that span multiple organ systems. This condition, also known as ‘post-acute sequelae of SARS-CoV-2 infection’ (PASC), presents a perplexing clinical picture with far-reaching implications, often persisting long after the acute phase.
While initial research focused on the immediate pulmonary impact of the virus, the recognition of COVID-19 as a multiorgan disruptor has unveiled a gamut of protracted and severe health issues. This review summarizes the primary effects of long COVID on the respiratory, cardiovascular, and nervous systems. It also delves into the mechanisms underlying these impacts and underscores the critical need for a comprehensive understanding of long COVID’s pathogenesis.
Source: Sideratou C-M, Papaneophytou C. Persisting Shadows: Unraveling the Impact of Long COVID-19 on Respiratory, Cardiovascular, and Nervous Systems. Infectious Disease Reports. 2023; 15(6):806-830. https://doi.org/10.3390/idr15060072 https://www.mdpi.com/2036-7449/15/6/72 (Full text)

Investigating the Human Intestinal DNA Virome and Predicting Disease-Associated Virus-Host Interactions in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Understanding how the human virome, and which of its constituents, contributes to health or disease states is reliant on obtaining comprehensive virome profiles. By combining DNA viromes from isolated virus-like particles (VLPs) and whole metagenomes from the same faecal sample of a small cohort of healthy individuals and patients with severe myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), we have obtained a more inclusive profile of the human intestinal DNA virome.

Key features are the identification of a core virome comprising tailed phages of the class Caudoviricetes, and a greater diversity of DNA viruses including extracellular phages and integrated prophages. Using an in silico approach, we predicted interactions between members of the Anaerotruncus genus and unique viruses present in ME/CFS microbiomes. This study therefore provides a framework and rationale for studies of larger cohorts of patients to further investigate disease-associated interactions between the intestinal virome and the bacteriome.

Source: Hsieh SY, Savva GM, Telatin A, Tiwari SK, Tariq MA, Newberry F, Seton KA, Booth C, Bansal AS, Wileman T, Adriaenssens EM, Carding SR. Investigating the Human Intestinal DNA Virome and Predicting Disease-Associated Virus-Host Interactions in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Int J Mol Sci. 2023 Dec 8;24(24):17267. doi: 10.3390/ijms242417267. PMID: 38139096. https://www.mdpi.com/1422-0067/24/24/17267 (Full text)

The association of insomnia with long COVID: An international collaborative study (ICOSS-II)

Abstract:

Objective: There is evidence of a strong association between insomnia and COVID-19, yet few studies have examined the relationship between insomnia and long COVID. This study aimed to investigate whether COVID-19 patients with pre-pandemic insomnia have a greater risk of developing long COVID and whether long COVID is in turn associated with higher incident rates of insomnia symptoms after infection.

Methods: Data were collected cross-sectionally (May-Dec 2021) as part of an international collaborative study involving participants from 16 countries. A total of 2311 participants (18-99 years old) with COVID-19 provided valid responses to a web-based survey about sleep, insomnia, and health-related variables. Log-binomial regression was used to assess bidirectional associations between insomnia and long COVID. Analyses were adjusted for age, sex, and health conditions, including sleep apnea, attention and memory problems, chronic fatigue, depression, and anxiety.

Results: COVID-19 patients with pre-pandemic insomnia showed a higher risk of developing long COVID than those without pre-pandemic insomnia (70.8% vs 51.4%; adjusted relative risk [RR]: 1.33, 95% confidence interval [CI]: 1.07-1.65). Among COVID-19 cases without pre-pandemic insomnia, the rates of incident insomnia symptoms after infection were 24.1% for short COVID cases and 60.6% for long COVID cases (p < .001). Compared with short COVID cases, long COVID cases were associated with an increased risk of developing insomnia symptoms (adjusted RR: 2.00; 95% CI: 1.50-2.66).

Conclusions: The findings support a bidirectional relationship between insomnia and long COVID. These findings highlight the importance of addressing sleep and insomnia in the prevention and management of long COVID.

Source: Chen SJ, Morin CM, Ivers H, Wing YK, Partinen M, Merikanto I, Holzinger B, Espie CA, De Gennaro L, Dauvilliers Y, Chung F, Yordanova J, Vidović D, Reis C, Plazzi G, Penzel T, Nadorff MR, Matsui K, Mota-Rolim S, Leger D, Landtblom AM, Korman M, Inoue Y, Hrubos-Strøm H, Chan NY, Bjelajac AK, Benedict C, Bjorvatn B. The association of insomnia with long COVID: An international collaborative study (ICOSS-II). Sleep Med. 2023 Dec;112:216-222. doi: 10.1016/j.sleep.2023.09.034. Epub 2023 Oct 24. PMID: 37922783. https://www.sciencedirect.com/science/article/abs/pii/S1389945723003672

Post-COVID exercise intolerance is associated with capillary alterations and immune dysregulations in skeletal muscles

Abstract:

The SARS-CoV-2 pandemic not only resulted in millions of acute infections worldwide, but also in many cases of post-infectious syndromes, colloquially referred to as “long COVID”. Due to the heterogeneous nature of symptoms and scarcity of available tissue samples, little is known about the underlying mechanisms.

We present an in-depth analysis of skeletal muscle biopsies obtained from eleven patients suffering from enduring fatigue and post-exertional malaise after an infection with SARS-CoV-2. Compared to two independent historical control cohorts, patients with post-COVID exertion intolerance had fewer capillaries, thicker capillary basement membranes and increased numbers of CD169+ macrophages. SARS-CoV-2 RNA could not be detected in the muscle tissues.

In addition, complement system related proteins were more abundant in the serum of patients with PCS, matching observations on the transcriptomic level in the muscle tissue. We hypothesize that the initial viral infection may have caused immune-mediated structural changes of the microvasculature, potentially explaining the exercise-dependent fatigue and muscle pain.

Source: Aschman, T., Wyler, E., Baum, O. et al. Post-COVID exercise intolerance is associated with capillary alterations and immune dysregulations in skeletal muscles. acta neuropathol commun 11, 193 (2023). https://doi.org/10.1186/s40478-023-01662-2 https://actaneurocomms.biomedcentral.com/articles/10.1186/s40478-023-01662-2 (Full text)