Long COVID is not a uniform syndrome: Evidence from person-level symptom clusters using latent class analysis

Abstract:

Background: The current study aims to enhance insight into the heterogeneity of long COVID by identifying symptom clusters and associated socio-demographic and health determinants.

Methods: A total of 458 participants (Mage 36.0 ± 11.9; 46.5% male) with persistent symptoms after COVID-19 completed an online self-report questionnaire including a 114-item symptom list. First, a k-means clustering analysis was performed to investigate overall clustering patterns and identify symptoms that provided meaningful distinctions between clusters. Next, a step-three latent class analysis (LCA) was performed based on these distinctive symptoms to analyze person-centered clusters. Finally, multinominal logistic models were used to identify determinants associated with the symptom clusters.

Results: From a 5-cluster solution obtained from k-means clustering, 30 distinctive symptoms were selected. Using LCA, six symptom classes were identified: moderate (20.7%) and high (20.7%) inflammatory symptoms, moderate malaise-neurocognitive symptoms (18.3%), high malaise-neurocognitive-psychosocial symptoms (17.0%), low-overall symptoms (13.3%) and high overall symptoms (9.8%). Sex, age, employment, COVID-19 suspicion, COVID-19 severity, number of acute COVID-19 symptoms, long COVID symptom duration, long COVID diagnosis, and impact of long COVID were associated with the different symptom clusters.

Conclusions: The current study’s findings characterize the heterogeneity in long COVID symptoms and underscore the importance of identifying determinants of different symptom clusters.

Source: van den Houdt SCM, Slurink IAL, Mertens G. Long COVID is not a uniform syndrome: Evidence from person-level symptom clusters using latent class analysis. J Infect Public Health. 2023 Dec 29;17(2):321-328. doi: 10.1016/j.jiph.2023.12.019. Epub ahead of print. PMID: 38183882. https://www.sciencedirect.com/science/article/pii/S1876034123004616 (Full text)

Preferential Impairment of Auditory Working Memory in Long COVID: An Observational Study of Undergraduate Medical Students

Abstract:

Background: Long COVID is a multisystem condition with prolonged symptoms that develop after recovery from the COVID-19 infection, often following a mild infection. Few studies have been conducted on cognitive function among medical students after recovery from mild COVID-19. This study aimed to assess the attention span and working memory (WM) capacity of medical students after six months of recovery.

Methods: A cross-sectional study was performed on 17 young adult medical students who had suffered a mild COVID-19 infection at least six months prior. Eighteen age-matched healthy medical students served as the controls. Audio-visual WM tasks and attention spans were assessed using computerized software for both the cases and controls.

Results: The mean ages of the case and control were 19.67±1.6 and 20.0±1.2 years, respectively. The most common symptoms among cases were fatigue (33%), weight loss (26%), and nasal stuffiness (13%). The overall proportion of correct responses across all visual and auditory WM tasks (p=0.085) and reaction times (p=0.609) did not differ between the cases and controls. However, the overall target hit rate of the auditory WM task was significantly lower in cases than in controls (p=0.002). This difference was not observed in the visual WM task (p=0.374).

Conclusion: In the current study, the overall WM functions (visual and auditory combined) and attention span did not differ between cases and controls. However, auditory WM performance was significantly impaired in patients compared with controls, indicating selective impairment of auditory WM in patients with long COVID.

Source: Manna S, Ghosh Dastidar S, S R, et al. (January 01, 2024) Preferential Impairment of Auditory Working Memory in Long COVID: An Observational Study of Undergraduate Medical Students. Cureus 16(1): e51457. doi:10.7759/cureus.51457 https://www.cureus.com/articles/217296-preferential-impairment-of-auditory-working-memory-in-long-covid-an-observational-study-of-undergraduate-medical-students#!/ (Full text)

Single-Cell RNA Sequencing Reveals Alterations in Patient Immune Cells with Pulmonary Long COVID-19 Complications

Abstract:

Since the emergence of the COVID-19 pandemic, the effects of SARS-CoV-2 have been extensively researched. While much is already known about the acute phase of the infection, increasing attention has turned to the prolonged symptoms experienced by a subset of individuals, commonly referred to as long COVID-19 patients. This study aims to delve deeper into the immune landscape of patients with prolonged symptoms by implementing single-cell mRNA analysis.
A 71-year-old COVID-19 patient presenting with persistent viral pneumonia was recruited, and peripheral blood samples were taken at 3 and 2 years post-acute infection onset. Patients and control peripheral blood mononuclear cells (PBMCs) were isolated and single-cell sequenced. Immune cell population identification was carried out using the ScType script.
Three months post-COVID-19 patients’ PBMCs contained a significantly larger immature neutrophil population compared to 2-year and control samples. However, the neutrophil balance shifted towards a more mature profile after 18 months. In addition, a notable increase in the CD8+ NKT-like cells could be observed in the 3-month patient sample as compared to the later one and control. The subsequent change in these cell populations over time may be an indicator of an ongoing failure to clear the SARS-CoV-2 infection and, thus, lead to chronic COVID-19 complications.
Source: Vaivode K, Saksis R, Litvina HD, Niedra H, Spriņģe ML, Krūmiņa U, Kloviņš J, Rovite V. Single-Cell RNA Sequencing Reveals Alterations in Patient Immune Cells with Pulmonary Long COVID-19 Complications. Current Issues in Molecular Biology. 2024; 46(1):461-468. https://doi.org/10.3390/cimb46010029 https://www.mdpi.com/1467-3045/46/1/29 (Full text)

The Multisystem Impact of Long COVID: A Comprehensive Review

Abstract:

Background: COVID-19 was responsible for the latest pandemic, shaking and reshaping healthcare systems worldwide. Its late clinical manifestations make it linger in medical memory as a debilitating illness over extended periods.
Methods: Recent literature was systematically analyzed to categorize and examine the symptomatology and pathophysiology of Long COVID across various bodily systems, including pulmonary, cardiovascular, gastrointestinal, neuropsychiatric, dermatological, renal, hematological, and endocrinological aspects.
Results: The review outlines the diverse clinical manifestations of Long COVID across multiple systems, emphasizing its complexity and challenges in diagnosis and treatment. Factors such as pre-existing conditions, initial COVID-19 severity, vaccination status, gender, and age were identified as influential in the manifestation and persistence of Long COVID symptoms. This condition is highlighted as a debilitating disease capable of enduring over an extended period and presenting new symptoms over time.
Conclusions: Long COVID emerges as a condition with intricate multi-systemic involvement, complicating its diagnosis and treatment. The findings underscore the necessity for a nuanced understanding of its diverse manifestations to effectively manage and address the evolving nature of this condition over time.
Source: Negrut, N.; Georgios, M.; Kampioti, S.; Bourelou, M.; Kopanyi, F.; Hassan, F.D.; Asowed, A.; Taleouine, F.Z.; Ferician, A.; Marian, P. The Multisystem Impact of Long COVID: A Comprehensive Review. Preprints 2024, 2024010099. https://doi.org/10.20944/preprints202401.0099.v1 https://www.preprints.org/manuscript/202401.0099/v1 (Full text available as PDF file)

The effectiveness of COVID-19 vaccines to prevent long COVID symptoms: staggered cohort study of data from the UK, Spain, and Estonia

Summary:

Background: Although vaccines have proved effective to prevent severe COVID-19, their effect on preventing long-term symptoms is not yet fully understood. We aimed to evaluate the overall effect of vaccination to prevent long COVID symptoms and assess comparative effectiveness of the most used vaccines (ChAdOx1 and BNT162b2).

Methods: We conducted a staggered cohort study using primary care records from the UK (Clinical Practice Research Datalink [CPRD] GOLD and AURUM), Catalonia, Spain (Information System for Research in Primary Care [SIDIAP]), and national health insurance claims from Estonia (CORIVA database). All adults who were registered for at least 180 days as of Jan 4, 2021 (the UK), Feb 20, 2021 (Spain), and Jan 28, 2021 (Estonia) comprised the source population. Vaccination status was used as a time-varying exposure, staggered by vaccine rollout period. Vaccinated people were further classified by vaccine brand according to their first dose received. The primary outcome definition of long COVID was defined as having at least one of 25 WHO-listed symptoms between 90 and 365 days after the date of a PCR-positive test or clinical diagnosis of COVID-19, with no history of that symptom 180 days before SARS-Cov-2 infection. Propensity score overlap weighting was applied separately for each cohort to minimise confounding. Sub-distribution hazard ratios (sHRs) were calculated to estimate vaccine effectiveness against long COVID, and empirically calibrated using negative control outcomes. Random effects meta-analyses across staggered cohorts were conducted to pool overall effect estimates.

Findings: A total of 1 618 395 (CPRD GOLD), 5 729 800 (CPRD AURUM), 2 744 821 (SIDIAP), and 77 603 (CORIVA) vaccinated people and 1 640 371 (CPRD GOLD), 5 860 564 (CPRD AURUM), 2 588 518 (SIDIAP), and 302 267 (CORIVA) unvaccinated people were included. Compared with unvaccinated people, overall HRs for long COVID symptoms in people vaccinated with a first dose of any COVID-19 vaccine were 0·54 (95% CI 0·44–0·67) in CPRD GOLD, 0·48 (0·34–0·68) in CPRD AURUM, 0·71 (0·55–0·91) in SIDIAP, and 0·59 (0·40–0·87) in CORIVA. A slightly stronger preventative effect was seen for the first dose of BNT162b2 than for ChAdOx1 (sHR 0·85 [0·60–1·20] in CPRD GOLD and 0·84 [0·74–0·94] in CPRD AURUM).

Interpretation: Vaccination against COVID-19 consistently reduced the risk of long COVID symptoms, which highlights the importance of vaccination to prevent persistent COVID-19 symptoms, particularly in adults.

Source: Martí Català, Núria Mercadé-Besora, Raivo Kolde,Nhung T H Trinh,Elena Roel,Edward Burn, Trishna Rathod-Mistry, Kristin Kostka, Wai Yi Man, Antonella Delmestri, Hedvig M E Nordeng, Anneli Uusküla, Talita Duarte-Salles, Daniel Prieto-Alhambra, Annika M Jödicke. The effectiveness of COVID-19 vaccines to prevent long COVID symptoms: staggered cohort study of data from the UK, Spain, and Estonia. The Lancet Respiratory Medicine. Published:January 11, 2024 ,DOI: https://doi.org/10.1016/S2213-2600(23)00414-9  https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(23)00414-9/fulltext (Full text)

Electroencephalographic Abnormalities in a Patient Suffering from Long-Term Neuropsychological Complications following SARS-CoV-2 Infection

Abstract:

Introduction: Emotional apathy has recently been identified as a common symptom of long COVID. While recent meta-analyses have demonstrated generalized EEG slowing with the emergence of delta rhythms in patients hospitalized for severe SARS-CoV-2 infection, no EEG study or dopamine transporter scintigraphy (DaTSCAN) has been performed in patients with long COVID presenting with apathy. The objective of this case report was to explore the pathophysiology of neuropsychological symptoms in long COVID.

Case presentation: A 47-year-old patient who developed a long COVID with prominent apathy following an initially clinically mild SARS-CoV-2 infection underwent neuropsychological assessment, cerebral MRI, DaTSCAN, and resting-state high-density EEG 7 months after SARS-CoV-2 infection. The EEG data were compared to those of 21 healthy participants. The patient presented with apathy, cognitive difficulties with dysexecutive syndrome, moderate attentional and verbal episodic memory disturbances, and resolution of premorbid mild gaming disorder, mild mood disturbances, and sleep disturbances. His MRI and DaTSCAN were unremarkable. EEG revealed a complex pattern of oscillatory abnormalities compared to the control group, with a strong increase in whole-scalp delta and beta band activity, as well as a decrease in alpha band activity. Overall, these effects were more prominent in the frontal-central-temporal region.

Conclusion: These results suggest widespread changes in EEG oscillatory patterns in a patient with long COVID characterized by neuropsychological complications with prominent apathy. Despite the inherent limitations of a case report, these results suggest dysfunction in the cortical networks involved in motivation and emotion.

Source: Benis D, Voruz P, Chiuve SC, Garibotto V, Assal F, Krack P, Péron J, Fleury V. Electroencephalographic Abnormalities in a Patient Suffering from Long-Term Neuropsychological Complications following SARS-CoV-2 Infection. Case Rep Neurol. 2023 Dec 5;16(1):6-17. doi: 10.1159/000535241. PMID: 38179211; PMCID: PMC10764086. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10764086/ (Full text)

Exploring the central mechanism of mind-regulation electroacupuncture in treatment of chronic fatigue syndrome with anxiety and depression comorbidity based on functional magnetic resonance imaging

Abstract:

in English, Chinese

Objectives: To observe the changes in the regional homogeneity (ReHo) and functional brain network in treatment of chronic fatigue syndrome (CFS) with anxiety and depression comorbidity with the mind-regulation electroacupuncture (EA), using resting-state functional magnetic resonance imaging (rs-fMRI).

Methods: Thirty CFS patients with anxiety and depression comorbidity were enrolled from medical staffs as the observation group. The other 30 healthy subjects were recruited from medical university students as the control group, matching gender, age and education years with the observation group. No any acupuncture intervention was delivered in the control group, and EA for regulating the mind was operated in the observation group. Main points were the emotional area of Sun‘s scalp acupuncture, the regions 1 and 8 of Sun‘s abdominal acupuncture. Supplementary acupoints included Baihui (GV 20), Guanyuan (CV 4) and bilateral.

Results: The scores of the five domains in MFI-20 (i.e. general fatigue, physical fatigue, mental fatigue, reduced motivation and reduced activity), the total score of MFI-20, and the scores of SDS, SAS and PSQI in the observation group before treatment were higher than those of the control group (P<0.05). Except the score of reduced motivation in MFI-20, the scores of the other domains and the total score of MFI-20, as well as the scores of SDS, SAS and PSQI after treatment were lower than those before treatment in the observation group (P<0.05).

Compared with the values before treatment, ReHo value was increased in the the right precuneus and decreased in the left inferior temporal gyrus and the left angular gyrus of the brain in the observation group after treatment. In the observation group, when compared with the control group, ReHo values were increased in the left inferior cerebral lobe, the interhemispheric region, the right occipital lobe and the thalamus; and it was reduced in the left middle temporal gyrus, the right posterior central gyrus, the right middle temporal gyrus, the right orbital middle frontal gyrus, the paracentral lobule and the right fusiform gyrus before treatment.

In the observation group, the functional connectivity was decreased between the right thalamus and the left posterior central gyrus, the right hippocampus and the right fusiform gyrus before treatment, respectively; it was re-constructed after treatment between the right thalamus and the left posterior central gyrus, and the right fusiform gyrus.

Compared with the control group, the functional connectivity between the right thalamus and the left posterior central gyrus, the right hippocampus, and the right fusiform gyrus was reduced before treatment; while after treatment, the functional connectivity was reduced between the right thalamus and the hippocampus in the observation group. With Spearman correlation analysis between the differential brain regions and the scores of MFI-20, SAS, SDS and PSQI, it was found that the left middle temporal gyrus, the paracentral lobule, the right precuneus, and the left inferior temporal gyrus had a partial positive correlation with the above clinical scales; and the interhemispheric region, the thalamus, the right fusiform gyrus, and the right middle temporal gyrus showed a partial negative correlation.

Conclusions: There is the decrease of ReHo in many brain regions and the numbers of the local brain functional network connectivity in CFS patients with anxiety and depression comorbidity. The mind-regulation electroacupuncture therapy may relieve the clinical symptoms of the patients through adjusting the abnormal brain regions and activating emotion-related brain regions.

Source: Zeng X, Feng C, Zhang M, Cheng W, Sun Z, Yang T. Exploring the central mechanism of mind-regulation electroacupuncture in treatment of chronic fatigue syndrome with anxiety and depression comorbidity based on functional magnetic resonance imaging. Zhongguo Zhen Jiu. 2023 Jan 12;44(1):3-11. English, Chinese. doi: 10.13703/j.0255-2930.20230603-k0003. PMID: 38191152. https://pubmed.ncbi.nlm.nih.gov/38191152/

Acupoint massage at Shenque (CV 8) for chronic fatigue syndrome: a randomized controlled trial

Abstract:

in English, Chinese

Objectives: To observe the clinical efficacy of acupoint massage at Shenque (CV 8) for chronic fatigue syndrome (CFS).

Methods: A total of 71 patients with CFS were randomized into an observation group (36 cases, 2 cases were eliminated, 3 cases dropped out) and a control group (35 cases). Using a specially made massage instrument, acupoint massage was adopted at the the five points of Shenque (CV 8), i.e. the center and the upper, lower, left, and right parts of the inner wall. The manipulation was given 10 min a time, once every 2 days, 3 times a week for 4 weeks continuously. No intervention was delivered in the control group. Before and after treatment, the scores of fatigue scale-14 (FS-14) and Pittsburgh sleep quality index (PSQI) were observed, and the clinical efficacy was evaluated in the both groups.

Results: After treatment, the physical fatigue and mental fatigue scores, as well as the total score of FS-14 were decreased compared with those before treatment in the observation group (P<0.001); the above scores in the observation group were lower than those in the control group (P<0.001). After treatment, excepted for the sleep time and hypnotic scores, the remaining item scores and the total score of PSQI were decreased compared with those before treatment in the observation group (P<0.05); the each item score and the total score of PSQI were lower than those in the control group (P<0.05). The total effective rate in the observation group was superior to that in the control group (P<0.01).

Conclusions: Acupoint massage at Shenque (CV 8) can effectively improve the fatigue state and sleep quality in patients with chronic fatigue syndrome.

Source: Li Z, Ji R, Yan C, Chen Y, Cao Z, Wang J. Acupoint massage at Shenque (CV 8) for chronic fatigue syndrome: a randomized controlled trial. Zhongguo Zhen Jiu. 2023 Jan 12;44(1):67-70. English, Chinese. doi: 10.13703/j.0255-2930.20230307-0002. PMID: 38191162. https://pubmed.ncbi.nlm.nih.gov/38191162/

Advancing Research and Treatment: An Overview of Clinical Trials in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Future Perspectives

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, debilitating, and multi-faceted illness. Heterogenous onset and clinical presentation with additional comorbidities make it difficult to diagnose, characterize, and successfully treat. Current treatment guidelines focus on symptom management, but with no clear target or causative mechanism, remission rates are low, and fewer than 5% of patients return to their pre-morbid activity levels. Therefore, there is an urgent need to undertake robust clinical trials to identify effective treatments.
This review synthesizes insights from clinical trials exploring pharmacological interventions and dietary supplements targeting immunological, metabolic, gastrointestinal, neurological, and neuroendocrine dysfunction in ME/CFS patients which require further exploration. Additionally, the trialling of alternative interventions in ME/CFS based on reported efficacy in the treatment of illnesses with overlapping symptomology is also discussed. Finally, we provide important considerations and make recommendations, focusing on outcome measures, to ensure the execution of future high-quality clinical trials to establish clinical efficacy of evidence-based interventions that are needed for adoption in clinical practice.
Source: Seton KA, Espejo-Oltra JA, Giménez-Orenga K, Haagmans R, Ramadan DJ, Mehlsen J on behalf of the European ME Research Group for Early Career Researchers (Young EMERG). Advancing Research and Treatment: An Overview of Clinical Trials in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Future Perspectives. Journal of Clinical Medicine. 2024; 13(2):325. https://doi.org/10.3390/jcm13020325 https://www.mdpi.com/2077-0383/13/2/325 (Full text)

Nutrition and Chronobiology as Key Components of Multidisciplinary Therapeutic Interventions for Fibromyalgia and Associated Chronic Fatigue Syndrome: A Narrative and Critical Review

Abstract:

Fibromyalgia (FM) is often accompanied by chronic fatigue syndrome (CFS). It is a poorly understood disorder that mainly affects women and leads to chronic pain, fatigue, and insomnia, among other symptoms, which decrease quality of life. Due to the inefficiency of current pharmacological treatments, increasing interest is being directed towards non-pharmacological multicomponent therapies. However, nutrition and chronobiology are often overlooked when developing multicomponent therapies.

This narrative and critical review explore the relevance of nutritional and chronobiological strategies in the therapeutic management of FM and the often-associated CFS. Reviewed literature offers scientific evidence for the association of dietary habits, nutrient levels, body composition, gut microbiota imbalance, chronobiological alterations, and their interrelation with the development and severity of symptoms. This review highlights the key role of nutrition and chronobiology as relevant and indispensable components in a multidisciplinary approach to FM and CFS.

Source: Carrasco-Querol N, Cabricano-Canga L, Bueno Hernández N, Gonçalves AQ, Caballol Angelats R, Pozo Ariza M, Martín-Borràs C, Montesó-Curto P, Castro Blanco E, Dalmau Llorca MR, et al. Nutrition and Chronobiology as Key Components of Multidisciplinary Therapeutic Interventions for Fibromyalgia and Associated Chronic Fatigue Syndrome: A Narrative and Critical Review. Nutrients. 2024; 16(2):182. https://doi.org/10.3390/nu16020182 https://www.mdpi.com/2072-6643/16/2/182 (Full text)