Tag: covid-19

Autoimmune complications of COVID-19 and potential consequences for long-lasting disease syndromes

Abstract:

The latest WHO report determined the increasing diversity within the CoV-2 omicron and its descendent lineages. Some heavily mutated offshoots of BA.5 and BA.2, such as BA.4.6, BF.7, BQ.1.1, and BA.2.75, are responsible for about 20% of infections and are spreading rapidly in multiple countries. It is a sign that Omicron subvariants are now developing a capacity to be more immune escaping and may contribute to a new wave of COVID-19.

Covid-19 infections often induce many alterations in human physiological defense and the natural control systems, with exacerbated activation of the inflammatory and homeostatic response, as for any infectious diseases. Severe activation of the early phase of hemostatic components, often occurs, leading to thrombotic complications and often contributing to a lethal outcome selectively in certain populations. Development of autoimmune complications increases the disease burden and lowers its prognosis.

While the true mechanism still remains unclear, it is believed to mainly be related to the host autoimmune responses as demonstrated, only in some patients suffering from the presence of autoantibodies that worsens the disease evolution. In fact in some studies the development of autoantibodies to angiotensin converting enzyme 2 (ACE2) was identified, and in other studies autoantibodies, thought to be targeting interferon or binding to annexin A1, or autoantibodies to phospholipids were seen. Moreover, the occurrence of autoimmune heparin induced thrombocytopenia has also been described in infected patients treated with heparin for controlling thrombogenicity.

This commentary focuses on the presence of various autoantibodies reported so far in Covid-19 diseases, exploring their association with the disease course and the durability of some related symptoms. Attempts are also made to further analyze the potential mechanism of actions and link the presence of antibodies with pathological complications.

Source: Amiral J, Seghatchian J. Autoimmune complications of COVID-19 and potential consequences for long-lasting disease syndromes. Transfus Apher Sci. 2022 Dec 17:103625. doi: 10.1016/j.transci.2022.103625. Epub ahead of print. PMID: 36585276; PMCID: PMC9757887. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9757887/ (Full text)

Cognitive impairments among patients in a long-COVID clinic: Prevalence, pattern and relation to illness severity, work function and quality of life

Abstract:

Background: A considerable proportion of people experience lingering symptoms after Coronavirus Disease 2019 (COVID-19). The aim of this study was to investigate the frequency, pattern and functional implications of cognitive impairments in patients at a long-COVID clinic who were referred after hospitalisation with COVID-19 or by their general practitioner.

Methods: Patients underwent cognitive screening and completed questionnaires regarding subjective cognition, work function and quality of life. Patients’ cognitive performance was compared with that of 150 age-, sex-, and education-matched healthy controls (HC) and with their individually expected performance calculated based on their age, sex and education.

Results: In total, 194 patients were assessed, on average 7 months (standard deviation: 4) after acute COVID-19.44-53 % of the patients displayed clinically relevant cognitive impairments compared to HC and to their expected performance, respectively. Moderate to large impairments were seen in global cognition and in working memory and executive function, while mild to moderate impairments occurred in verbal fluency, verbal learning and memory. Hospitalised (n = 91) and non-hospitalised (n = 103) patients showed similar degree of cognitive impairments in analyses adjusted for age and time since illness. Patients in the cognitively impaired group were older, more often hospitalised, had a higher BMI and more frequent asthma, and were more often female. More objective cognitive impairment was associated with more subjective cognitive difficulties, poorer work function and lower quality of life.

Limitations: The study was cross-sectional, which precludes causality inferences.

Conclusions: These findings underscore the need to assess and treat cognitive impairments in patients at long-COVID clinics.

Source: Miskowiak KW, Pedersen JK, Gunnarsson DV, Roikjer TK, Podlekareva D, Hansen H, Dall CH, Johnsen S. Cognitive impairments among patients in a long-COVID clinic: Prevalence, pattern and relation to illness severity, work function and quality of life. J Affect Disord. 2022 Dec 28;324:162-169. doi: 10.1016/j.jad.2022.12.122. Epub ahead of print. PMID: 36586593; PMCID: PMC9795797. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9795797/ (Full text)

Brain correlates of subjective cognitive complaints in COVID-19 survivors: A multimodal magnetic resonance imaging study

Abstract:

Cognitive impairment represents a leading residual symptom of COVID-19 infection, which lasts for months after the virus clearance. Up-to-date scientific reports documented a wide spectrum of brain changes in COVID-19 survivors following the illness’s resolution, mainly related to neurological and neuropsychiatric consequences.

Preliminary insights suggest abnormal brain metabolism, microstructure, and functionality as neural under-layer of post-acute cognitive dysfunction. While previous works focused on brain correlates of impaired cognition as objectively assessed, herein we investigated long-term neural correlates of subjective cognitive decline in a sample of 58 COVID-19 survivors with a multimodal imaging approach.

Diffusion Tensor Imaging (DTI) analyses revealed widespread white matter disruption in the sub-group of cognitive complainers compared to the non-complainer one, as indexed by increased axial, radial, and mean diffusivity in several commissural, projection and associative fibres. Likewise, the Multivoxel Pattern Connectivity analysis (MVPA) revealed highly discriminant patterns of functional connectivity in resting-state among the two groups in the right frontal pole and in the middle temporal gyrus, suggestive of inefficient dynamic modulation of frontal brain activity and possible metacognitive dysfunction at rest.

Beyond COVID-19 actual pathophysiological brain processes, our findings point toward brain connectome disruption conceivably translating into clinical post-COVID cognitive symptomatology. Our results could pave the way for a potential brain signature of cognitive complaints experienced by COVID-19 survivors, possibly leading to identify early therapeutic targets and thus mitigating its detrimental long-term impact on quality of life in the post-COVID-19 stages.

Source: Paolini M, Palladini M, Mazza MG, Colombo F, Vai B, Rovere-Querini P, Falini A, Poletti S, Benedetti F. Brain correlates of subjective cognitive complaints in COVID-19 survivors: A multimodal magnetic resonance imaging study. Eur Neuropsychopharmacol. 2022 Dec 12;68:1-10. doi: 10.1016/j.euroneuro.2022.12.002. Epub ahead of print. PMID: 36640728. https://www.sciencedirect.com/science/article/pii/S0924977X22009130 (Full study)

A Review of Long COVID With a Special Focus on Its Cardiovascular Manifestations

Abstract:

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been the cause of the century’s worst pandemic so far: coronavirus disease 2019 (COVID-19). It has led to unprecedented mortality and morbidity, resulting in devastating consequences worldwide. The acute manifestations of COVID-19 including respiratory as well as multisystem involvement have been causes of great concern among physicians. However, the long-term effects of the coronavirus have left many patients battling with chronic symptoms, ranging from extreme fatigue to cardiomyopathy. In this article, we review the chronic manifestations of COVID-19 with a focus on cardiovascular manifestations.

We discuss the pathophysiology, post-acute sequelae, clinical manifestations, approach to the laboratory diagnosis of cardiovascular manifestations of long COVID, and a proposed multidisciplinary treatment method. We also explore the relationship between vaccination and the long COVID syndrome.

Source: Yousif E, Premraj S. A Review of Long COVID With a Special Focus on Its Cardiovascular Manifestations. Cureus. 2022 Nov 27;14(11):e31933. doi: 10.7759/cureus.31933. PMID: 36582565; PMCID: PMC9793803. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9793803/ (Full text)

A scoping review of regulatory T cell dynamics in convalescent COVID-19 patients – indications for their potential involvement in the development of Long COVID?

Abstract:

Background: Recovery from coronavirus disease 2019 (COVID-19) can be impaired by the persistence of symptoms or new-onset health complications, commonly referred to as Long COVID. In a subset of patients, Long COVID is associated with immune system perturbations of unknown etiology, which could be related to compromised immunoregulatory mechanisms.

Objective: The objective of this scoping review was to summarize the existing literature regarding the frequency and functionality of Tregs in convalescent COVID-19 patients and to explore indications for their potential involvement in the development of Long COVID.

Design: A systematic search of studies investigating Tregs during COVID-19 convalescence was conducted on MEDLINE (via Pubmed) and Web of Science.

Results: The literature search yielded 17 relevant studies, of which three included a distinct cohort of patients with Long COVID. The reviewed studies suggest that the Treg population of COVID-19 patients can reconstitute quantitatively and functionally during recovery. However, the comparison between recovered and seronegative controls revealed that an infection-induced dysregulation of the Treg compartment can be sustained for at least several months. The small number of studies investigating Tregs in Long COVID allowed no firm conclusions to be drawn about their involvement in the syndrome’s etiology. Yet, even almost one year post-infection Long COVID patients exhibit significantly altered proportions of Tregs within the CD4+ T cell population.

Conclusions: Persistent alterations in cell frequency in Long COVID patients indicate that Treg dysregulation might be linked to immune system-associated sequelae. Future studies should aim to address the association of Treg adaptations with different symptom clusters and blood parameters beyond the sole quantification of cell frequencies while adhering to consensualized phenotyping strategies.

Source: Haunhorst S, Bloch W, Javelle F, Krüger K, Baumgart S, Drube S, Lemhöfer C, Reuken P, Stallmach A, Müller M, Zielinski CE, Pletz MW, Gabriel HHW, Puta C. A scoping review of regulatory T cell dynamics in convalescent COVID-19 patients – indications for their potential involvement in the development of Long COVID? Front Immunol. 2022 Dec 13;13:1070994. doi: 10.3389/fimmu.2022.1070994. PMID: 36582234; PMCID: PMC9792979. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9792979/ (Full text)

Natural and Semi-Synthetic Flavonoid Anti-SARS-CoV-2 Agents for the Treatment of Long COVID-19 Disease and Neurodegenerative Disorders of Cognitive Decline

Abstract:

The aim of this review is to highlight the beneficial attributes of flavonoids, a diverse family of widely-distributed polyphenolic phytochemicals that have beneficial cell and tissue protective properties. Phytochemicals are widely distributed in plants, herbs and shrubs used in traditional complimentary medical formulations for centuries. The bioactive components that convey beneficial medicinal effects in these complex herbal preparations are now being identified using network pharmacology and molecular docking procedures that identify their molecular targets. Flavonoids have anti-oxidant, anti-inflammatory, antiviral, antibacterial and anti-cancer properties that have inspired the development of potent multifunctional derivatised flavonoids of improved efficacy.

The antiviral properties of flavonoids and the emergence of the severe acute respiratory syndrome (SARS-CoV-2) pandemic has resulted in a resurgence of interest in phytochemicals in the search for efficacious compounds that can prevent viral infection or replication, with many promising plant compounds identified. Promising semi-synthetic flavonoid derivatives have also been developed that inhibit multiple pathological neurodegenerative processes; these offer considerable promise in the treatment of diseases of cognitive decline. Clinical trials are currently being undertaken to evaluate the efficacy of dietary supplements rich in flavonoids for the treatment of virally-mediated diseases. Such trials are expected to identify flavonoids with cell and tissue protective properties that can be harnessed in biomedical applications that may serve as supportive adjunctive procedures to conventional anti-viral drug therapies against diseases such as COVID-19.

Source: Melrose J, Smith MM. Natural and Semi-Synthetic Flavonoid Anti-SARS-CoV-2 Agents for the Treatment of Long COVID-19 Disease and Neurodegenerative Disorders of Cognitive Decline. Front Biosci (Elite Ed). 2022 Oct 9;14(4):27. doi: 10.31083/j.fbe1404027. PMID: 36575843.  https://www.imrpress.com/journal/FBE/14/4/10.31083/j.fbe1404027/htm (Full text)

Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study

Abstract:

Background and purpose: Long COVID with regard to the neurological system deserves more attention, as a surge of treated patients are being discharged from the hospital. As the dynamic changes in white matter after two years remain unknown, this characteristic was the focus of this study.

Methods: We investigated 17 recovered COVID-19 patients at two years after discharge. Diffusion tensor imaging, neurite orientation dispersion and density imaging were performed to identify white matter integrity and changes from one to two years after discharge. Data for 13 revisited healthy controls were collected as a reference. Subscales of the Wechsler Intelligence scale were used to assess cognitive function. Repeated-measures ANOVA was used to detect longitudinal changes in 17 recovered COVID-19 patients and 13 healthy controls after one-year follow-up. Correlations between diffusion metrics, cognitive function, and other clinical characteristics (i.e., inflammatory factors) were also analyzed.

Results: Longitudinal analysis showed the recovery trends of large-scale brain regions, with small-scale brain region deterioration from one year to two years after SARS-CoV-2 infection. However, persistent white matter abnormalities were noted at two years after discharge. Longitudinal changes of cognitive function showed no group difference. But cross-sectional cognitive difference between recovered COVID-19 patients and revisited HCs was detected. Inflammation levels in the acute stage correlated positively with white matter abnormalities and negatively with cognitive function. Moreover, the more abnormal the white matter was at two years, the greater was the cognitive deficit present.

Conclusion: Recovered COVID-19 patients showed longitudinal recovery trends of white matter. But also had persistent white matter abnormalities at two years after discharge. Inflammation levels in the acute stage may be considered predictors of cognition and white matter integrity, and the white matter microstructure acts as a biomarker of cognitive function in recovered COVID-19 patients. These findings provide an objective basis for early clinical intervention.

Source: Huang S, Zhou X, Zhao W, Du Y, Yang D, Huang Y, Chen Y, Zhang H, Yang G, Liu J, Luo H. Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study. Theranostics. 2023 Jan 1;13(2):724-735. doi: 10.7150/thno.79902. PMID: 36632218; PMCID: PMC9830428. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9830428/ (Full text)

A cross-sectional, multicenter survey of the prevalence and risk factors for Long COVID

Abstract:

Long-term sequelae of the coronavirus disease (COVID-19) constitute Long COVID. Although Long COVID has been reported globally, its risk factors and effects on quality of life (QOL) remain unclear. We conducted a cross-sectional study using questionnaires and electronic medical records of COVID-19 patients who were diagnosed or hospitalized at five facilities in Japan.

Responses were obtained from 285 out of 1,150 patients. More than half of the participants reported Long COVID symptoms of varying severity 1 year after COVID-19. Common sequelae included fatigue, dyspnea, alopecia, concentration problems, memory problems, sleeplessness, and joint pain, which often significantly reduced their QOL. COVID-19 severity was strongly associated with sputum production, chest pain, dyspnea, sore throat, and diarrhea, but not with fatigue, dysgeusia, anosmia, alopecia, and sleeplessness. Fatigue, dysgeusia, anosmia, alopecia, and sleeplessness affected the QOL among participants with asymptomatic or mild COVID-19 during the acute phase. Moreover, these sequelae persisted for prolonged periods.

Source: Imoto W, Yamada K, Kawai R, Imai T, Kawamoto K, Uji M, Kanda H, Takada M, Ohno Y, Ohtani H, Kono M, Hikiishi A, Eguchi Y, Namikawa H, Kawaguchi T, Kakeya H. A cross-sectional, multicenter survey of the prevalence and risk factors for Long COVID. Sci Rep. 2022 Dec 27;12(1):22413. doi: 10.1038/s41598-022-25398-6. PMID: 36575200; PMCID: PMC9793373. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9793373/ (Full text)

Autonomic Nerve Involvement in Post-Acute Sequelae of SARS-CoV-2 Syndrome (PASC)

Abstract:

The novel SARS-CoV-2 virus and resulting COVID-19 global pandemic emerged in 2019 and continues into 2022. While mortality from COVID-19 is slowly declining, a subset of patients have developed chronic, debilitating symptoms following complete recovery from acute infection with COVID-19. Termed as post-acute sequelae of SARS-CoV-2 syndrome (PASC), the underlying pathophysiology of PASC is still not well understood.

Given the similarity between the clinical phenotypes of PASC and postural orthostatic tachycardia syndrome (POTS), it has been postulated that dysautonomia may play a role in the pathophysiology of PASC. However, there have been only a few studies that have examined autonomic function in PASC.

In this retrospective study, we performed an analysis of autonomic nerve function testing in PASC patients and compared the results with those of POTS patients and healthy controls. Our results suggest that a significant number of PASC patients have abnormal autonomic function tests, and their clinical features are indistinguishable from POTS.

Source: Chung TH, Azar A. Autonomic Nerve Involvement in Post-Acute Sequelae of SARS-CoV-2 Syndrome (PASC). J Clin Med. 2022 Dec 22;12(1):73. doi: 10.3390/jcm12010073. PMID: 36614874; PMCID: PMC9821608. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9821608/ (Full text)

Prevalence of Post–COVID-19 Conditions Depends on the Method of Assessment

To the Editor—In their systematic review and meta-analysis on the global prevalence of long coronavirus disease 2019 (COVID-19), Chen et al report that a significant share of patients with COVID-19 suffer from sequelae of acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection [1]. The authors performed a database search in PubMed, Embase, and iSearch and included 50 studies comprising hospitalized and nonhospitalized patients from the Americas, Europe, and Asia, of which 41 studies were meta-analyzed. The estimated pooled prevalence of a post–COVID-19 condition was 0.43 (95% confidence interval, .39–.46) [1].

Concerning a post–COVID-19 condition, or long COVID, and their global burden of disease, we think it is important to bear in mind that many studies (including our own [2], which was in the meta-analysis) assess long COVID symptoms via self-report/questionnaires. Self-reported outcomes do not necessarily match clinical reports that are based on physical and/or technical examinations. Thus, there is a difference between functional impairment based on objective medical findings and self-estimation, giving rise to potential detection bias, as the authors briefly mention in the supplement. Moreover, possible bias through elevated media attention, resulting in potentially altered response behavior, must be considered.

Making causal links between nonspecific symptoms, such as dizziness, headache, or fatigue, to SARS-CoV-2 or acute COVID-19 remains challenging [3]. Furthermore, precise pathophysiological mechanisms underlying specific long COVID symptoms have not been fully elucidated [4, 5]. Fatigue, for example, is associated with several chronic conditions and its prevalence in the population is estimated to be in the same range as found in SARS-CoV-2 cases in the present meta-analysis [6]. With regard to the World Health Organization definition, a post–COVID-19 condition may represent a diagnosis per exclusion in many cases [7]. Nonetheless, even if the prevalence of long COVID was overestimated in the underlying studies, COVID-19 sequelae pose a considerable burden on health, social insurance systems, and economies worldwide given the high attack rate of SARS-CoV-2 [8].

Source: Lampl BMJ, Leitzmann MF, Salzberger B. Prevalence of Post-COVID-19 Conditions Depends on the Method of Assessment. J Infect Dis. 2023 Jan 11;227(2):306. doi: 10.1093/infdis/jiac467. PMID: 36546758. https://academic.oup.com/jid/article/227/2/306/6853665 (Full text)