Tag: long Covid

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)

Investigating the possible mechanisms of autonomic dysfunction post-COVID-19

Abstract:

Patients with long COVID suffer from many neurological manifestations that persist for 3 months following infection by SARS-CoV-2. Autonomic dysfunction (AD) or dysautonomia is one complication of long COVID that causes patients to experience fatigue, dizziness, syncope, dyspnea, orthostatic intolerance, nausea, vomiting, and heart palpitations. The pathophysiology behind AD onset post-COVID is largely unknown. As such, this review aims to highlight the potential mechanisms by which AD occurs in patients with long COVID.

The first proposed mechanism includes the direct invasion of the hypothalamus or the medulla by SARS-CoV-2. Entry to these autonomic centers may occur through the neuronal or hematogenous routes. However, evidence so far indicates that neurological manifestations such as AD are caused indirectly.

Another mechanism is autoimmunity whereby autoantibodies against different receptors and glycoproteins expressed on cellular membranes are produced. Additionally, persistent inflammation and hypoxia can work separately or together to promote sympathetic overactivation in a bidirectional interaction. Renin-angiotensin system imbalance can also drive AD in long COVID through the downregulation of relevant receptors and formation of autoantibodies. Understanding the pathophysiology of AD post-COVID-19 may help provide early diagnosis and better therapy for patients.

Source: Jammoul M, Naddour J, Madi A, Reslan MA, Hatoum F, Zeineddine J, Abou-Kheir W, Lawand N. Investigating the possible mechanisms of autonomic dysfunction post-COVID-19. Auton Neurosci. 2022 Dec 24;245:103071. doi: 10.1016/j.autneu.2022.103071. Epub ahead of print. PMID: 36580747; PMCID: PMC9789535. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9789535/ (Full text)

Long Covid: Untangling the Complex Syndrome and the Search for Therapeutics

Abstract:

Long Covid can affect anyone who has previously had acute COVID-19. The root causes of this syndrome are still unknown, and no effective therapeutics are available. This complex syndrome, with a wide array of symptoms, is still evolving. Given the dire situation, it is important to identify the causes of Long Covid and the changes occurring within the immune system of affected patients to figure out how to treat it.
The immune system intersects with the persistent viral fragments and blood clots that are implicated in this syndrome; understanding how these complex systems interact may help in untangling the puzzling physiopathology of Long Covid and identifying mitigation measures to provide patients some relief. In this paper, we discuss evidence-based findings and formulate hypotheses on the mechanisms underlying Long Covid’s physiopathology and propose potential therapeutic options.
Source: Haque A, Pant AB. Long Covid: Untangling the Complex Syndrome and the Search for Therapeutics. Viruses. 2023; 15(1):42. https://doi.org/10.3390/v15010042 https://www.mdpi.com/1999-4915/15/1/42 (Full text)

Deep Dive into the Long Haul: Analysis of Symptom Clusters and Risk Factors for Post-Acute Sequelae of COVID-19 to Inform Clinical Care

Abstract:

Long COVID is a chronic condition characterized by symptoms such as fatigue, dyspnea, and cognitive impairment that persist or relapse months after an acute infection with the SARS-CoV-2 virus. Many distinct symptoms have been attributed to Long COVID; however, little is known about the potential clustering of these symptoms and risk factors that may predispose patients to certain clusters. In this study, an electronic survey was sent to patients in the UC San Diego Health (UCSDH) system who tested positive for COVID-19, querying if patients were experiencing symptoms consistent with Long COVID.

Based on survey results, along with patient demographics reported in the electronic health record (EHR), linear and logistic regression models were used to examine putative risk factors, and exploratory factor analysis was performed to determine symptom clusters. Among 999 survey respondents, increased odds of Long COVID (n = 421; 42%) and greater Long COVID symptom burden were associated with female sex (OR = 1.73, 99% CI: 1.16-2.58; β = 0.48, 0.22-0.75), COVID-19 hospitalization (OR = 4.51, 2.50-8.43; β = 0.48, 0.17-0.78), and poorer pre-COVID self-rated health (OR = 0.75, 0.57-0.97; β = -0.19, -0.32–0.07).

Over one-fifth of Long COVID patients screened positive for depression and/or anxiety, the latter of which was associated with younger age (OR = 0.96, 0.94-0.99). Factor analysis of 16 self-reported symptoms suggested five symptom clusters-gastrointestinal (GI), musculoskeletal (MSK), neurocognitive (NC), airway (AW), and cardiopulmonary (CP), with older age (β = 0.21, 0.11-0.30) and mixed race (β = 0.27, 0.04-0.51) being associated with greater MSK symptom burden. Greater NC symptom burden was associated with increased odds of depression (OR = 5.86, 2.71-13.8) and anxiety (OR = 2.83, 1.36-6.14).

These results can inform clinicians in identifying patients at increased risk for Long COVID-related medical issues, particularly neurocognitive symptoms and symptom clusters, as well as informing health systems to manage operational expectations on a population-health level.

Source: Goldhaber NH, Kohn JN, Ogan WS, Sitapati A, Longhurst CA, Wang A, Lee S, Hong S, Horton LE. Deep Dive into the Long Haul: Analysis of Symptom Clusters and Risk Factors for Post-Acute Sequelae of COVID-19 to Inform Clinical Care. Int J Environ Res Public Health. 2022 Dec 15;19(24):16841. doi: 10.3390/ijerph192416841. PMID: 36554723; PMCID: PMC9778884. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9778884/ (Full text)

Low molecular weight cytotoxic components (DAMPs) form the post-COVID-19 syndrome

Abstract:

We studied the role of cytotoxic components (DAMPs) formed in the body of patients with COVID-19 in ensuring the long-term preservation of post-COVID-19 manifestations and the possibility of creating an experimental model by transferring DAMPs to rats. In patients with post-COVID-19 syndrome (PCS) 2 months after SARS-CoV-2 infection we determined the presence of cytotoxic components in the blood serum (Terasaki test, Dunaliella viridis test and content of DAMPs).

In post-COVID-19 syndrome patients with a high content of serum cytotoxic oligopeptide fraction (selective group, n = 16) we determined the number of leukocytes, lymphocytes, neutrophil granulocytes and monocytes in the blood, the content of C-reactive protein (CRP), the concentration of C3 and C4 complement components and circulating immune complexes, the serum content of IL-6, IL -10, IL-18, TNF-α, phagocytic activity of neutrophils, presence of neutrophil traps and autoantibodies ANA.

It has been shown that in patients with PCS, there are components with cytotoxicity in the blood serum, form specific immunopathological patterns, which are characterized by: an increased content of CRP, complement system components C3 and C4 and cytokines (TNF-α, IL-6, IL-10, IL-18) activation, the formation of a wide range of autoantibodies ANA, the low efficiency of endocytosis in oxygen-independent phagocytosis; their phagocytic activity reaches its functional limit, and against this background, activation of neutrophil traps occurs, which can contribute to further induction of DAMPs. This self-sustaining cell-killing activation provided long-term preservation of PCS symptoms.

The transfer of blood serum components from selective group patients with PCS to rats was accompanied by the appearance of cytotoxic components in them which induced sensitization and immunopathological reactions. Preventive administration of a biologically active substance with polyfunctional properties MF to experimental animals “corrected” the initial functional state of the body’s immune-metabolic system and eliminated or facilitated immuno-inflammatory reactions.

Source: Klimova EM, Bozhkov AI, Lavinska OV, Drozdova LA, Kurhuzova NI. Low molecular weight cytotoxic components (DAMPs) form the post-COVID-19 syndrome. Immunobiology. 2023 Jan;228(1):152316. doi: 10.1016/j.imbio.2022.152316. Epub 2022 Dec 20. PMID: 36565610; PMCID: PMC9764760. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9764760/ (Full text)

Generalisable long COVID subtypes: Findings from the NIH N3C and RECOVER programmes

Abstract:

Background: Stratification of patients with post-acute sequelae of SARS-CoV-2 infection (PASC, or long COVID) would allow precision clinical management strategies. However, long COVID is incompletely understood and characterised by a wide range of manifestations that are difficult to analyse computationally. Additionally, the generalisability of machine learning classification of COVID-19 clinical outcomes has rarely been tested.

Methods: We present a method for computationally modelling PASC phenotype data based on electronic healthcare records (EHRs) and for assessing pairwise phenotypic similarity between patients using semantic similarity. Our approach defines a nonlinear similarity function that maps from a feature space of phenotypic abnormalities to a matrix of pairwise patient similarity that can be clustered using unsupervised machine learning.

Findings: We found six clusters of PASC patients, each with distinct profiles of phenotypic abnormalities, including clusters with distinct pulmonary, neuropsychiatric, and cardiovascular abnormalities, and a cluster associated with broad, severe manifestations and increased mortality. There was significant association of cluster membership with a range of pre-existing conditions and measures of severity during acute COVID-19. We assigned new patients from other healthcare centres to clusters by maximum semantic similarity to the original patients, and showed that the clusters were generalisable across different hospital systems. The increased mortality rate originally identified in one cluster was consistently observed in patients assigned to that cluster in other hospital systems.

Interpretation: Semantic phenotypic clustering provides a foundation for assigning patients to stratified subgroups for natural history or therapy studies on PASC.

Source: Reese JT, Blau H, Casiraghi E, Bergquist T, Loomba JJ, Callahan TJ, Laraway B, Antonescu C, Coleman B, Gargano M, Wilkins KJ, Cappelletti L, Fontana T, Ammar N, Antony B, Murali TM, Caufield JH, Karlebach G, McMurry JA, Williams A, Moffitt R, Banerjee J, Solomonides AE, Davis H, Kostka K, Valentini G, Sahner D, Chute CG, Madlock-Brown C, Haendel MA, Robinson PN; N3C Consortium; RECOVER Consortium. Generalisable long COVID subtypes: Findings from the NIH N3C and RECOVER programmes. EBioMedicine. 2022 Dec 21;87:104413. doi: 10.1016/j.ebiom.2022.104413. Epub ahead of print. PMID: 36563487; PMCID: PMC9769411. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9769411/ (Full text)

Characteristics and predictors of Long COVID among diagnosed cases of COVID-19

Abstract:

Background: Long COVID or long-term symptoms after COVID-19 has the ability to affect health and quality of life. Knowledge about the burden and predictors could aid in their prevention and management. Most of the studies are from high-income countries and focus on severe acute COVID-19 cases. We did this study to estimate the incidence and identify the characteristics and predictors of Long COVID among our patients.

Methodology: We recruited adult (≥18 years) patients who were diagnosed as Reverse Transcription Polymerase Chain Reaction (RTPCR) confirmed SARS-COV-2 infection and were either hospitalized or tested on outpatient basis. Eligible participants were followed up telephonically after four weeks and six months of diagnosis of SARS-COV-2 infection to collect data on sociodemographic, clinical history, vaccination history, Cycle threshold (Ct) values during diagnosis and other variables. Characteristics of Long COVID were elicited, and multivariable logistic regression was done to find the predictors of Long COVID.

Results: We have analyzed 487 and 371 individual data with a median follow-up of 44 days (Inter quartile range (IQR): 39,47) and 223 days (IQR:195,251), respectively. Overall, Long COVID was reported by 29.2% (95% Confidence interval (CI): 25.3%,33.4%) and 9.4% (95% CI: 6.7%,12.9%) of participants at four weeks and six months of follow-up, respectively. Incidence of Long COVID among patients with mild/moderate disease (n = 415) was 23.4% (95% CI: 19.5%,27.7%) as compared to 62.5% (95% CI: 50.7%,73%) in severe/critical cases(n = 72) at four weeks of follow-up. At six months, the incidence among mild/moderate (n = 319) was 7.2% (95% CI:4.6%,10.6%) as compared to 23.1% (95% CI:12.5%,36.8%) in severe/critical (n = 52). The most common Long COVID symptom was fatigue. Statistically significant predictors of Long COVID at four weeks of follow-up were-Pre-existing medical conditions (Adjusted Odds ratio (aOR) = 2.00, 95% CI: 1.16,3.44), having a higher number of symptoms during acute phase of COVID-19 disease (aOR = 11.24, 95% CI: 4.00,31.51), two doses of COVID-19 vaccination (aOR = 2.32, 95% CI: 1.17,4.58), the severity of illness (aOR = 5.71, 95% CI: 3.00,10.89) and being admitted to hospital (Odds ratio (OR) = 3.89, 95% CI: 2.49,6.08).

Conclusion: A considerable proportion of COVID-19 cases reported Long COVID symptoms. More research is needed in Long COVID to objectively assess the symptoms and find the biological and radiological markers.

Source: Arjun MC, Singh AK, Pal D, Das K, G A, Venkateshan M, Mishra B, Patro BK, Mohapatra PR, Subba SH. Characteristics and predictors of Long COVID among diagnosed cases of COVID-19. PLoS One. 2022 Dec 20;17(12):e0278825. doi: 10.1371/journal.pone.0278825. PMID: 36538532; PMCID: PMC9767341. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9767341/ (Full text)

Long COVID: major findings, mechanisms and recommendations

Abstract:

Long COVID is an often debilitating illness that occurs in at least 10% of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. More than 200 symptoms have been identified with impacts on multiple organ systems. At least 65 million individuals worldwide are estimated to have long COVID, with cases increasing daily. Biomedical research has made substantial progress in identifying various pathophysiological changes and risk factors and in characterizing the illness; further, similarities with other viral-onset illnesses such as myalgic encephalomyelitis/chronic fatigue syndrome and postural orthostatic tachycardia syndrome have laid the groundwork for research in the field.

In this Review, we explore the current literature and highlight key findings, the overlap with other conditions, the variable onset of symptoms, long COVID in children and the impact of vaccinations. Although these key findings are critical to understanding long COVID, current diagnostic and treatment options are insufficient, and clinical trials must be prioritized that address leading hypotheses. Additionally, to strengthen long COVID research, future studies must account for biases and SARS-CoV-2 testing issues, build on viral-onset research, be inclusive of marginalized populations and meaningfully engage patients throughout the research process.

Source: Davis, H.E., McCorkell, L., Vogel, J.M. et al. Long COVID: major findings, mechanisms and recommendations. Nat Rev Microbiol (2023). https://doi.org/10.1038/s41579-022-00846-2 https://www.nature.com/articles/s41579-022-00846-2