Category: Overlapping Illnesses

Pathogenesis Underlying Neurological Manifestations of Long COVID Syndrome and Potential Therapeutics

Abstract:

The development of long-term symptoms of coronavirus disease 2019 (COVID-19) more than four weeks after primary infection, termed “long COVID” or post-acute sequela of COVID-19 (PASC), can implicate persistent neurological complications in up to one third of patients and present as fatigue, “brain fog”, headaches, cognitive impairment, dysautonomia, neuropsychiatric symptoms, anosmia, hypogeusia, and peripheral neuropathy. Pathogenic mechanisms of these symptoms of long COVID remain largely unclear; however, several hypotheses implicate both nervous system and systemic pathogenic mechanisms such as SARS-CoV2 viral persistence and neuroinvasion, abnormal immunological response, autoimmunity, coagulopathies, and endotheliopathy.
Outside of the CNS, SARS-CoV-2 can invade the support and stem cells of the olfactory epithelium leading to persistent alterations to olfactory function. SARS-CoV-2 infection may induce abnormalities in innate and adaptive immunity including monocyte expansion, T-cell exhaustion, and prolonged cytokine release, which may cause neuroinflammatory responses and microglia activation, white matter abnormalities, and microvascular changes. Additionally, microvascular clot formation can occlude capillaries and endotheliopathy, due to SARS-CoV-2 protease activity and complement activation, can contribute to hypoxic neuronal injury and blood–brain barrier dysfunction, respectively.
Current therapeutics target pathological mechanisms by employing antivirals, decreasing inflammation, and promoting olfactory epithelium regeneration. Thus, from laboratory evidence and clinical trials in the literature, we sought to synthesize the pathophysiological pathways underlying neurological symptoms of long COVID and potential therapeutics.
Source: Leng A, Shah M, Ahmad SA, Premraj L, Wildi K, Li Bassi G, Pardo CA, Choi A, Cho S-M. Pathogenesis Underlying Neurological Manifestations of Long COVID Syndrome and Potential Therapeutics. Cells. 2023; 12(5):816. https://doi.org/10.3390/cells12050816 (Full text)

“Long COVID”: the current state of the problem. Review of foreign scientific and medical publications

Abstract:

Not all the patients who are diagnosed with COVID-19 can completely recover; some of them experience miscellaneous persistent symptoms that subsequently wax or wane.  As the COVID-19 pandemic continues, the number of people with long-term symptoms is rapidly increasing, adding to the burden on healthcare and society. The prevalence of the consequences of COVID-19 varies between studies, with some reporting that more than half of hospitalized patients have prolonged symptoms for at least 6 months after acute SARS-CoV-2 infection, and others for more than 12 months. The overall prevalence of residual symptoms in patients infected with SARS-CoV-2 is currently estimated to be 10–30%.

This clinical syndrome is commonly referred to as post-acute COVID syndrome (PACS) or long COVID. This multifactorial syndrome is characterised by a variety of debilitating symptoms, including fatigue, brain fog, postural hypotension with tachycardia, and post-exertional malaise. Many of the observations of post COVID-19 condition, including changes in immune, cardiovascular, gastrointestinal, nervous and autonomic systems, are shared with the symptoms described in myalgic encephalitis/chronic fatigue syndrome (ME/CFS) patients.

Comprehensive longitudinal symptom monitoring is required to confirm of diagnosis, uncover the mechanisms of post-COVID-19-associated ME/CFS, and develop prevention and treatment measures. Current absence of the effective treatment reflects the unclear causes of the post COVID-19 conditions which cannot be targeted properly until the mechanism is established and confirmed.

The multisystem aspects of long COVID remain poorly understood. The COVID-19 pandemic has exposed a significant gap in knowledge about the post-acute consequences of infectious diseases and the need for a unified nomenclature and classification of post-COVID conditions, diagnostic criteria, and reliable assessments of these disorders. Unraveling the complex biology of PACS relies on the identification of biomarkers in plasma and tissue samples taken from individuals infected with SARS-CoV-2 that will allow classification of the phenotypes of patients who develop PACS.

For the full treatment of patients with post-COVID syndrome, multidisciplinary therapy and rehabilitation are required. Understanding the physiological mechanisms underlying the long-term clinical manifestations of COVID-19 and the post-COVID-19 state is vital to the development of appropriate effective therapies.

Source: Golota A.S., Vologzhanin D.A., Kamilova T.A., Sсherbak S.G., Makarenko S.V. “Long COVID”: the current state of the problem. Review of foreign scientific and medical publications // Physical and rehabilitation medicine, medical rehabilitation. – 2023. – Vol. 5. – N. 1. doi: 10.36425/rehab121733 (Full text available in Russian)

Symptomatic Characteristics of Hypozincemia Detected in Long COVID Patients

Abstract:

Objectives: The aim of this study was to determine the characteristics of hypozincemia in long COVID patients.
Methods: This study was a single-center retrospective observational study for outpatients who visited the long COVID clinic established in a university hospital during the period from 15 February 2021 to 28 February 2022. Characteristics of patients with a serum zinc concentration lower than 70 μg/dL (10.7 μmol/L) were compared with characteristics of patients with normozincemia.
Results: In a total of 194 patients with long COVID after excluding 32 patients, hypozincemia was detected in 43 patients (22.2%) including 16 male patients (37.2%) and 27 female patients (62.8%). Among various parameters including the background characteristics of the patients and medical histories, the patients with hypozincemia were significantly older than the patients with normozincemia (median age: 50 vs. 39 years). A significant negative correlation was found between serum zinc concentrations and age in male patients (R = −0.39; p < 0.01) but not in female patients. In addition, there was no significant correlation between serum zinc levels and inflammatory markers. General fatigue was the most frequent symptom in both male patients with hypozincemia (9 out of 16: 56.3%) and female patients with hypozincemia (8 out of 27: 29.6%). Patients with severe hypozincemia (serum zinc level lower than 60 μg/dL) had major complaints of dysosmia and dysgeusia, which were more frequent complaints than general fatigue.
Conclusions: The most frequent symptom in long COVID patients with hypozincemia was general fatigue. Serum zinc levels should be measured in long COVID patients with general fatigue, particularly in male patients.
Source: Matsuda Y, Tokumasu K, Otsuka Y, Sunada N, Honda H, Sakurada Y, Nakano Y, Hasegawa T, Obika M, Ueda K, Otsuka F. Symptomatic Characteristics of Hypozincemia Detected in Long COVID Patients. Journal of Clinical Medicine. 2023; 12(5):2062. https://doi.org/10.3390/jcm12052062 https://www.mdpi.com/2077-0383/12/5/2062 (Full text)

The role of immune activation and antigen persistence in acute and long COVID

Abstract:

In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered the global coronavirus disease 2019 (COVID-19) pandemic. Although most infections cause a self-limited syndrome comparable to other upper respiratory viral pathogens, a portion of individuals develop severe illness leading to substantial morbidity and mortality. Furthermore, an estimated 10%-20% of SARS-CoV-2 infections are followed by post-acute sequelae of COVID-19 (PASC), or long COVID.

Long COVID is associated with a wide variety of clinical manifestations including cardiopulmonary complications, persistent fatigue, and neurocognitive dysfunction. Severe acute COVID-19 is associated with hyperactivation and increased inflammation, which may be an underlying cause of long COVID in a subset of individuals. However, the immunologic mechanisms driving long COVID development are still under investigation.

Early in the pandemic, our group and others observed immune dysregulation persisted into convalescence after acute COVID-19. We subsequently observed persistent immune dysregulation in a cohort of individuals experiencing long COVID. We demonstrated increased SARS-CoV-2-specific CD4+ and CD8+ T-cell responses and antibody affinity in patients experiencing long COVID symptoms. These data suggest a portion of long COVID symptoms may be due to chronic immune activation and the presence of persistent SARS-CoV-2 antigen.

This review summarizes the COVID-19 literature to date detailing acute COVID-19 and convalescence and how these observations relate to the development of long COVID. In addition, we discuss recent findings in support of persistent antigen and the evidence that this phenomenon contributes to local and systemic inflammation and the heterogeneous nature of clinical manifestations seen in long COVID.

Source: Opsteen S, Files JK, Fram T, Erdmann N. The role of immune activation and antigen persistence in acute and long COVID. J Investig Med. 2023 Mar 6:10815589231158041. doi: 10.1177/10815589231158041. Epub ahead of print. PMID: 36879504; PMCID: PMC9996119. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9996119/ (Full text)

Autoantibodies against chemokines post-SARS-CoV-2 infection correlate with disease course

Abstract:

Infection with severe acute respiratory syndrome coronavirus 2 associates with diverse symptoms, which can persist for months. While antiviral antibodies are protective, those targeting interferons and other immune factors are associated with adverse coronavirus disease 2019 (COVID-19) outcomes.

Here we discovered that antibodies against specific chemokines were omnipresent post-COVID-19, were associated with favorable disease outcome and negatively correlated with the development of long COVID at 1 yr post-infection. Chemokine antibodies were also present in HIV-1 infection and autoimmune disorders, but they targeted different chemokines compared with COVID-19. Monoclonal antibodies derived from COVID-19 convalescents that bound to the chemokine N-loop impaired cell migration.

Given the role of chemokines in orchestrating immune cell trafficking, naturally arising chemokine antibodies may modulate the inflammatory response and thus bear therapeutic potential.

Source: Muri J, Cecchinato V, Cavalli A, Shanbhag AA, Matkovic M, Biggiogero M, Maida PA, Moritz J, Toscano C, Ghovehoud E, Furlan R, Barbic F, Voza A, De Nadai G, Cervia C, Zurbuchen Y, Taeschler P, Murray LA, Danelon-Sargenti G, Moro S, Gong T, Piffaretti P, Bianchini F, Crivelli V, Podešvová L, Pedotti M, Jarrossay D, Sgrignani J, Thelen S, Uhr M, Bernasconi E, Rauch A, Manzo A, Ciurea A, Rocchi MBL, Varani L, Moser B, Bottazzi B, Thelen M, Fallon BA, Boyman O, Mantovani A, Garzoni C, Franzetti-Pellanda A, Uguccioni M, Robbiani DF. Autoantibodies against chemokines post-SARS-CoV-2 infection correlate with disease course. Nat Immunol. 2023 Mar 6. doi: 10.1038/s41590-023-01445-w. Epub ahead of print. PMID: 36879067. https://www.nature.com/articles/s41590-023-01445-w (Full text)

Aging and long COVID-19 syndrome: what’s new in 2023?

Abstract:

Since 2019 that saw the onset of the COVID-19 pandemic, its ongoing impact on many older adults remains a persistent public health concern, especially among those who report suffering from long or post-acute COVID-19 disease health challenges. This report presents data published largely since January 1 2023 on this topic and concerning: Long COVID or COVID-19, Older Adults, Post-Acute COVID-19 Outcomes, and Prevention.

Data show that even though long COVID-19 was discussed in 2021 at some length, it still remains a relatively unchartered poorly understood topic in which a sizeable percentage of older adult COVID-19 survivors may experience delayed features of breathing, movement, cognitive and mental health challenges. What causes the observed and perceived problems, what may help to identify who is at risk, and what will reduce these remains unknown, but may benefit from insightful research and extended observations and possible multi pronged efforts that target those symptoms of most concern.

Source: Marks R. Aging and long COVID-19 syndrome: what’s new in 2023? MOJ Gerontol Ger. 2023;8(1):9-14. DOI: 10.15406/mojgg.2023.08.00302 (Full text)

Quality of life and ability to work of patients with Post-COVID syndrome in relation to the number of existing symptoms and the duration since infection up to 12 months: a cross-sectional study

Abstract:

Purpose: Following SARS-CoV-2 virus infection, patients may suffer from long-lasting symptoms regardless of disease severity. Preliminary results show limitations in health-related quality of life (HRQoL). The aim of this study is to show a possible change depending on the duration since infection and the accumulation of symptoms. Additionally, other possible influencing factors will be analyzed.

Methods: The study population consisted of patients (18-65 years) presenting to the Post-COVID outpatient clinic of the University Hospital Jena, Germany, between March and October 2021. The HRQoL was assessed by the use of the RehabNeQ and the SF-36. Data analysis was descriptive with frequencies, means, and/or percentages. In addition, a univariate analysis of variance was performed to show the dependence of physical and psychological HRQoL on specific factors. This was finally tested for significance at an alpha level of 5%.

Results: Data from 318 patients were analyzed, most of whom had 3-6 months of infection (56%) and 5-10 symptoms persisted (60.4%). Both mental (MCS) and physical sum score (PCS) of HRQoL were significantly lower than those of the German normal population (p < .001). The number of remaining symptoms (MCS p = .0034, PCS p = .000) as well as the perceived ability to work (MCS p = .007, PCS p = .000) influenced the HRQoL.

Conclusion: The HRQoL of patients with Post-COVID-syndrome is still reduced months after infection and so is their occupational performance. In particular, the number of symptoms could have an influence on this deficit, which would need to be further investigated. Further research is needed to detect other factors influencing HRQoL and to implement appropriate therapeutic interventions.

Source: Lemhöfer C, Sturm C, Loudovici-Krug D, Guntenbrunner C, Bülow M, Reuken P, Quickert S, Best N. Quality of life and ability to work of patients with Post-COVID syndrome in relation to the number of existing symptoms and the duration since infection up to 12 months: a cross-sectional study. Qual Life Res. 2023 Mar 3:1–12. doi: 10.1007/s11136-023-03369-2. Epub ahead of print. PMID: 36869248; PMCID: PMC9984128. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9984128/ (Full text)

Conceptualising the episodic nature of disability among adults living with Long COVID: a qualitative study

Abstract:

Introduction: Our aim was to describe episodic nature of disability among adults living with Long COVID.

Methods: We conducted a community-engaged qualitative descriptive study involving online semistructured interviews and participant visual illustrations. We recruited participants via collaborator community organisations in Canada, Ireland, UK and USA. We recruited adults who self-identified as living with Long COVID with diversity in age, gender, race/ethnicity, sexual orientation and duration since initial COVID infection between December 2021 and May 2022. We used a semistructured interview guide to explore experiences of disability living with Long COVID, specifically health-related challenges and how they were experienced over time. We asked participants to draw their health trajectory and conducted a group-based content analysis.

Results: Among the 40 participants, the median age was 39 years (IQR: 32-49); majority were women (63%), white (73%), heterosexual (75%) and living with Long COVID for ≥1 year (83%). Participants described their disability experiences as episodic in nature, characterised by fluctuations in presence and severity of health-related challenges (disability) that may occur both within a day and over the long-term living with Long COVID. They described living with ‘ups and downs’, ‘flare-ups’ and ‘peaks’ followed by ‘crashes’, ‘troughs’ and ‘valleys’, likened to a ‘yo-yo’, ‘rolling hills’ and ‘rollercoaster ride’ with ‘relapsing/remitting’, ‘waxing/waning’, ‘fluctuations’ in health. Drawn illustrations demonstrated variety of trajectories across health dimensions, some more episodic than others. Uncertainty intersected with the episodic nature of disability, characterised as unpredictability of episodes, their length, severity and triggers, and process of long-term trajectory, which had implications on broader health.

Conclusion: Among this sample of adults living with Long COVID, experiences of disability were described as episodic, characterised by fluctuating health challenges, which may be unpredictable in nature. Results can help to better understand experiences of disability among adults living with Long COVID to inform healthcare and rehabilitation.

Source: O’Brien KK, Brown DA, McDuff K, St Clair-Sullivan N, Solomon P, Chan Carusone S, McCorkell L, Wei H, Goulding S, O’Hara M, Thomson C, Roche N, Stokes R, Vera JH, Erlandson KM, Bergin C, Robinson L, Cheung AM, Torres B, Avery L, Bannan C, Harding R. Conceptualising the episodic nature of disability among adults living with Long COVID: a qualitative study. BMJ Glob Health. 2023 Mar;8(3):e011276. doi: 10.1136/bmjgh-2022-011276. PMID: 36863719; PMCID: PMC9979585. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9979585/ (Full text)

Effect of Repetitive Transcranial Magnetic Stimulation on Long Coronavirus Disease 2019 with Fatigue and Cognitive Dysfunction

Abstract:

Objectives: There is no established treatment for chronic fatigue and various cognitive dysfunctions (brain fog) caused by long coronavirus disease 2019 (COVID-19). We aimed to clarify the effectiveness of repetitive transcranial magnetic stimulation (rTMS) for treating these symptoms.

Methods: High-frequency rTMS was applied to occipital and frontal lobes in 12 patients with chronic fatigue and cognitive dysfunction 3 months after severe acute respiratory syndrome coronavirus 2 infection. Before and after ten sessions of rTMS, Brief Fatigue Inventory (BFI), Apathy Scale (AS), and Wechsler Adult Intelligence Scale-fourth edition (WAIS4) were determined and N-isopropyl-p-[123I]iodoamphetamine single photon emission computed tomography (SPECT) was performed.

Results: Twelve subjects completed ten sessions of rTMS without adverse events. The mean age of the subjects was 44.3 ± 10.7 years, and the mean duration of illness was 202.4 ± 114.5 days. BFI, which was 5.7 ± 2.3 before the intervention, decreased significantly to 1.9 ± 1.8 after the intervention. The AS was significantly decreased after the intervention from 19.2 ± 8.7 to 10.3 ± 7.2. All WAIS4 sub-items were significantly improved after rTMS intervention, and the full-scale intelligence quotient increased from 94.6 ± 10.9 to 104.4 ± 13.0. Hypoperfusion in the bilateral occipital and frontal lobes observed on SPECT improved in extent and severity after ten sessions of rTMS.

Conclusions: Although we are still in the early stages of exploring the effects of rTMS, the procedure has the potential for use as a new non-invasive treatment for the symptoms of long COVID.

Source: Sasaki N, Yamatoku M, Tsuchida T, Sato H, Yamaguchi K. Effect of Repetitive Transcranial Magnetic Stimulation on Long Coronavirus Disease 2019 with Fatigue and Cognitive Dysfunction. Prog Rehabil Med. 2023 Feb 28;8:20230004. doi: 10.2490/prm.20230004. PMID: 36861061; PMCID: PMC9968785. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9968785/ (Full text)

Could the fibromyalgia syndrome be triggered or enhanced by COVID-19?

Abstract:

Fibromyalgia (FM) is a complex disease with an uncertain aetiology and intricate pathophysiology. Although its genesis is not fully explained, potential environmental factors, such as viral infections might trigger FM or worsen patients’ clinical outcomes.

The SARS-CoV-2 virus may affect central and peripheral nervous systems, leading to musculoskeletal, neurological, and psychological disturbances. These symptoms might persist at least 12 months beyond the recovery, often referred to as post-COVID syndrome, which resembles FM syndrome. In this sense, we argued the potential consequences of COVID-19 exclusively on FM syndrome.

First, we have described post-COVID syndrome and its painful symptoms. Afterwards, we argued whether FM syndrome could be triggered or enhanced by COVID-19 infection or by numerous and persistent stressors imposed daily by the pandemic setting (isolation, uncertainty, depression, mental stress, generalized anxiety, and fear of the virus). In addition, we have demonstrated similarities between pathophysiological mechanisms and cardinal symptoms of FM and COVID-19, speculating that SARS-CoV-2 might represent a critical mediator of FM or an exacerbator of its symptoms once both syndromes share similar mechanisms and complaints.

Therefore, pharmacologic and non-pharmacological approaches commonly used to treat FM could serve as strategic therapies to attenuate painful and neurological manifestations of post-COVID syndrome. Although it is still theoretical, clinicians and researchers should be alert of patients who develop symptoms similar to FM or those who had their FM symptoms increased post-COVID to manage them better.

Source: Fialho MFP, Brum ES, Oliveira SM. Could the fibromyalgia syndrome be triggered or enhanced by COVID-19? Inflammopharmacology. 2023 Feb 27:1–19. doi: 10.1007/s10787-023-01160-w. Epub ahead of print. PMID: 36849853; PMCID: PMC9970139. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970139/ (Full text)