Impaired parasympathetic function in long-COVID postural orthostatic tachycardia syndrome – a case-control study

Abstract:

Purpose: Eighty percent of patients infected by SARS-CoV-2 report persistence of one symptom beyond the 4-week convalescent period. Those with orthostatic tachycardia and orthostatic symptoms mimicking postural tachycardia syndrome, they are defined as Long-COVID POTS [LCP]. This case-control study investigated potential differences in autonomic cardiovascular regulation between LCP patients and healthy controls.

Methods: Thirteen LCP and 16 healthy controls, all female subjects, were studied without medications. Continuous blood pressure and ECG were recorded during orthostatic stress test, respiratory sinus arrhythmia, and Valsalva maneuver. Time domain and power spectral analysis of heart rate [HR] and systolic blood pressure [SBP] variability were computed characterizing cardiac autonomic control and sympathetic peripheral vasoconstriction.

Results: LCP had higher deltaHR (+ 40 ± 6 vs. + 21 ± 3 bpm, p = 0.004) and deltaSBP (+ 8 ± 4 vs. -1 ± 2 mmHg, p = 0.04) upon standing; 47% had impaired Valsalva maneuver ratio compared with 6.2% in controls (p = 0.01). Spectral analysis revealed that LCP had lower RMSSD (32.1 ± 4.6 vs. 48.9 ± 6.8 ms, p = 0.04) and HFRRI, both in absolute (349 ± 105 vs. 851 ± 253ms2, p = 0.03) and normalized units (32 ± 4 vs. 46 ± 4 n.u., p = 0.02). LFSBP was similar between groups.

Conclusions: LCP have reduced cardiovagal modulation, but normal sympathetic cardiac and vasoconstrictive functions. Impaired parasympathetic function may contribute to the pathogenesis of Long-COVID POTS syndrome.

Source: Rigo S, Urechie V, Diedrich A, Okamoto LE, Biaggioni I, Shibao CA. Impaired parasympathetic function in long-COVID postural orthostatic tachycardia syndrome – a case-control study. Bioelectron Med. 2023 Sep 6;9(1):19. doi: 10.1186/s42234-023-00121-6. PMID: 37670400; PMCID: PMC10481607. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10481607/ (Full text)

The global challenges of the long COVID-19

Abstract:

COVID-19 may lead to a perseverance of symptoms after recovery from the disease, a condition known as long COVID, characterized by continual cognitive, somatic and behavioral symptoms. SARS-CoV-2 infection triggers different molecular to tissue level events, given by the inherent features of each patient. The potential pathological changes which determine the array of symptoms are arduous to anticipate.

There is an increasing interest to develop treatment strategies for survivors who experience a long COVID. In this respect, considering the anti-inflammatory, anti-oxidative and cytoprotective effects of melatonin (MEL) on viral infections, its potential links with COVID-19 should be researched. Several studies suggest that administration of MEL may prevent clinical deterioration and even death in patients with acute and long COVID-19.

This paper briefly reviews the current status of knowledge of the pathogenic, clinical, and therapeutic features of Long COVID-19 and forthcoming directions for research and implications for the management and therapy of the disease are analyzed.

Source: Leonor Chacin-Bonilla. The global challenges of the long COVID-19. Journal of Clinical Images and Medical Case Reports. ISSN 2766-7820 https://jcimcr.org/pdfs/JCIMCR-v4-2512.pdf (Full text)

Post-COVID symptoms are associated with endotypes reflecting poor inflammatory and hemostatic modulation

Abstract:

Introduction: Persistent symptoms after COVID-19 infection (“long COVID”) negatively affects almost half of COVID-19 survivors. Despite its prevalence, its pathophysiology is poorly understood, with multiple host systems likely affected. Here, we followed patients from hospital to discharge and used a systems-biology approach to identify mechanisms of long COVID.

Methods: RNA-seq was performed on whole blood collected early in hospital and 4-12 weeks after discharge from 24 adult COVID-19 patients (10 reported post-COVID symptoms after discharge). Differential gene expression analysis, pathway enrichment, and machine learning methods were used to identify underlying mechanisms for post-COVID symptom development.

Results: Compared to patients with post-COVID symptoms, patients without post-COVID symptoms had larger temporal gene expression changes associated with downregulation of inflammatory and coagulation genes over time. Patients could also be separated into three patient endotypes with differing mechanistic trajectories, which was validated in another published patient cohort. The “Resolved” endotype (lowest rate of post-COVID symptoms) had robust inflammatory and hemostatic responses in hospital that resolved after discharge. Conversely, the inflammatory/hemostatic responses of “Suppressive” and “Unresolved” endotypes (higher rates of patients with post-COVID symptoms) were persistently dampened and activated, respectively. These endotypes were accurately defined by specific blood gene expression signatures (6-7 genes) for potential clinical stratification.

Discussion: This study allowed analysis of long COVID whole blood transcriptomics trajectories while accounting for the issue of patient heterogeneity. Two of the three identified and externally validated endotypes (“Unresolved” and “Suppressive”) were associated with higher rates of post-COVID symptoms and either persistently activated or suppressed inflammation and coagulation processes. Gene biomarkers in blood could potentially be used clinically to stratify patients into different endotypes, paving the way for personalized long COVID treatment.

Source: An AY, Baghela A, Zhang PGY, Blimkie TM, Gauthier J, Kaufmann DE, Acton E, Lee AHY, Levesque RC, Hancock REW. Post-COVID symptoms are associated with endotypes reflecting poor inflammatory and hemostatic modulation. Front Immunol. 2023 Aug 23;14:1243689. doi: 10.3389/fimmu.2023.1243689. PMID: 37680625; PMCID: PMC10482103. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10482103/ (Full text)

Structural and functional impairments of skeletal muscle in patients with post-acute sequelae of SARS-CoV-2 infection

Abstract:

Background: Following acute COVID-19, a substantial proportion of patients showed symptoms and sequelae for several months, namely the post-acute sequelae of COVID-19 (PASC) syndrome. Major phenomena are exercise intolerance, muscle weakness and fatigue. We aimed to investigate the physiopathology of exercise intolerance in patients with PASC syndrome by structural and functional analyses of skeletal muscle.

Methods: At least 3 months after infection, non-hospitalized patients with PASC (n=11,ys:54±11; PASC) and patients without long-term symptoms (n=12,ys:49±9; CTRL) visited the laboratory on four non-consecutive days. Spirometry, lung diffusion capacity and quality of life were assessed at rest. Cardiopulmonary incremental exercise test was performed. Oxygen consumption (VO2) kinetics were determined by moderate-intensity exercises. Muscle oxidative capacity (k) was assessed by near-infrared spectroscopy. Histochemical analysis, O2 flux (JO2) by high-resolution respirometry, and quantification of key molecular markers of mitochondrial biogenesis and dynamics were performed in vastus lateralis biopsies.

Results: Pulmonary and cardiac functions were within normal range in all patients. VO2peak was lower in PASC than CTRL (24.7±5.0vs32.9±7.4mL*min-1*kg-1, respectively, P<.05). VO2 kinetics was slower in PASC than CTRL (41±12vs30±9s-1, P<.05). k was lower in PASC than CTRL (1.54±0.49vs2.07±0.51min-1, P<.05). Citrate synthase, PGC1alfa and JO2 for mitochondrial complex II were significantly lower in PASC vs CTRL (all P<.05).

Conclusion: In our cohort of patients with PASC, we showed limited exercise tolerance mainly due to “peripheral” determinants. Substantial reductions were observed for biomarkers of mitochondrial function, content, and biogenesis. PASC syndrome appears to negatively impact skeletal muscle function, although the disease is an heterogenous condition.

Source: Colosio M, Brocca L, Gatti M, Neri M, Crea E, Cadile F, Canepari M, Pellegrino MA, Polla B, Porcelli S, Bottinelli R. Structural and functional impairments of skeletal muscle in patients with post-acute sequelae of SARS-CoV-2 infection. J Appl Physiol (1985). 2023 Sep 7. doi: 10.1152/japplphysiol.00158.2023. Epub ahead of print. PMID: 37675472. https://journals.physiology.org/doi/abs/10.1152/japplphysiol.00158.2023 (Full text available as PDF file)

Unveiling the Mysteries of Long COVID Syndrome: Exploring the Distinct Tissue and Organ Pathologies Linked to Prolonged COVID-19 Symptoms

Abstract:

The ongoing battle against the coronavirus disease 2019 (COVID-19) pandemic has encountered a complex aspect with the emergence of long COVID syndrome. There has been a growing prevalence of COVID-19-affected individuals experiencing persistent and diverse symptoms that extend beyond the initial infection phase. The phenomenon known as long COVID syndrome raises significant questions about the underlying mechanisms driving these enduring symptoms.

This comprehensive analysis explores the complex domain of long COVID syndrome with a view to shed light on the specific tissue and organ pathologies contributing to its intricate nature. This review aims to analyze the various clinical manifestations of this condition across different bodily systems and explore potential mechanisms such as viral persistence, immune dysregulation, autoimmunity, and molecular mimicry. The goal is to gain a better understanding of the intricate network of pathologies contributing to long COVID syndrome.

Understanding these distinct pathological indicators provides valuable insights into comprehending the complexities of long COVID and presents opportunities for developing more accurate diagnostic and therapeutic strategies, thereby improving the quality of patient care by effectively  addressing the ever-changing medical challenge in a more focused manner.

Source: Sapna F, Deepa F, Sakshi F, et al. (September 02, 2023) Unveiling the Mysteries of Long COVID Syndrome: Exploring the Distinct Tissue and Organ Pathologies Linked to Prolonged COVID-19 Symptoms. Cureus 15(9): e44588. DOI 10.7759/cureus.44588. https://assets.cureus.com/uploads/review_article/pdf/182615/20230903-23556-1g56qsl.pdf (Full text)

Fatigue, chronic fatigue syndrome and migraine: Intersecting the lines through a cross-sectional study in patients with episodic and chronic migraine

Abstract:

Objectives: Fatigue is a common symptom occurring in a variety of disorders. Chronic fatigue syndrome (CFS) is characterized by debilitating fatigue as the core symptom. The risk of CFS is nearly 1.5 times higher in migraine while headaches have been reported in 59% of cases with CFS. However, details of its occurrence and severity remain largely unexplored.

The primary objective of our study was to determine the occurrence and severity of fatigue and CFS in patients with episodic and chronic migraine. The secondary objectives were to define their relationship with other common comorbidities.

Materials and methods: 60 migraine patients (30 each, episodic [EM] and chronic migraine [CM]) were recruited from Neurology Outpatient Department, GIPMER a tertiary referral center in New Delhi, India. Patients’ headache severity was analyzed using the Headache impact test-6 (HIT-6) score while fatigue and other migraine accompaniments were assessed using Fatigue severity scale (FSS), Chalder fatigue scale, CDC diagnostic criteria for CFS, American College of Rheumatology Diagnostic Criteria for fibromyalgia, Hamilton Depression Scale, the Generalized Anxiety Disorder 7-Item Scale, and Epworth sleepiness Scale (ESS). Comparative analysis was further done among migraine patients with and without fatigue and CFS.

Results: The mean HIT-6 score was significantly higher in CM versus EM. The CM group had a higher mean FSS score (47.87 vs. 37.3 in EM; P = 0.004), a percentage of patients with severe fatigue (60% vs. 20% in EM; P = 0.004), and a higher percentage of patients with pathological fatigue (83.3% vs. 63.3% in EM; P = 0.04). Around 23.33% of CM patients fulfilled the criteria of CFS. Fatigue correlated positively with severity, frequency, attack duration and chronicity of the migraine episodes, along with depression, anxiety, and excessive daytime sleepiness.

Conclusion: Fatigue and related comorbid disorders are significantly more common in CM than in EM, expanding the morbidity of the condition and underscores the need to address these accompanying symptoms for devising a holistic treatment plan.

Source: Kumar H, Dhamija K, Duggal A, Khwaja GA, Roshan S. Fatigue, chronic fatigue syndrome and migraine: Intersecting the lines through a cross-sectional study in patients with episodic and chronic migraine. J Neurosci Rural Pract. 2023 Jul-Sep;14(3):424-431. doi: 10.25259/JNRP_63_2022. Epub 2023 Apr 20. PMID: 37692810; PMCID: PMC10483198. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10483198/ (Full text)

Efficiency of comprehensive rehabilitation of chronic fatigue syndrome due to coronavirus infections COVID-19

Abstract:

The aim of the study was to study the effectiveness of complex rehabilitation in patients with chronic fatigue syndrome caused by coronavirus infections.

In 120 patients with a confirmed diagnosis of SARS-CoV-2 (COVID-19) aged 20-58 years, post-COVID syndrome or chronic fatigue syndrome was detected, 52 men and 68 women. Patients had asthenic, cognitive, vegetative manifestations, sleep disorders, smell and taste disorders, anxiety and depression.

Patients received drug therapy: succinic acid preparations, brain metabolic drugs, stimulating antidepressants, sleeping pills – melatonin and B vitamins, among other things, received micropolarization of the head and translingualneurostimulation.

The results of treatment confirmed the effectiveness of the proposed conservative therapy. The neurological symptoms of post-COVID syndrome – chronic fatigue syndrome (CFS) were studied in 120 patients with a confirmed diagnosis of SARS-CoV-2 (COVID-19), aged 20-58 years.

Patients were examined according to the “Questionnaire for the detection of asthenia”, “Mini Mental State Assessment (MMSE)”, et.al. Sleep disorders were studied using the Epworth Sleepiness Scale, anxiety and depression were studied using the “Questionnaire for Determining Anxiety and Depression”.

The patients were divided into 2 groups: the main group (MG) – 69 patients and the control group (CG) – 51 patients. Patients with MG and CG received drug therapy: succinic acid preparations, brain metabolic drugs, stimulating antidepressants, sleeping pills – melatonin and B vitamins. And patients with MG, among other things, received micropolarization of the head and translingualneurostimulation.

Source: Z.I. Adambaev, I.A. Kilichev, A.B. Nurzhonov, N.Yu. Khudoyberganov, and M.R. Niyazmetov. Efficiency of comprehensive rehabilitation of chronic fatigue syndrome due to coronavirus infections COVID-19. BIO Web of Conferences 65, 05039 (2023) https://www.bio-conferences.org/articles/bioconf/abs/2023/10/bioconf_ebwff2023_05039/bioconf_ebwff2023_05039.html (Full text available as PDF file)

Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID?

Abstract:

Both myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) and long COVID (LC) are characterized by similar immunological alterations, persistence of chronic viral infection, autoimmunity, chronic inflammatory state, viral reactivation, hypocortisolism, and microclot formation. They also present with similar symptoms such as asthenia, exercise intolerance, sleep disorders, cognitive dysfunction, and neurological and gastrointestinal complaints. In addition, both pathologies present Epstein-Barr virus (EBV) reactivation, indicating the possibility of this virus being the link between both pathologies.

Therefore, we propose that latency and recurrent EBV reactivation could generate an acquired immunodeficiency syndrome in three steps: first, an acquired EBV immunodeficiency develops in individuals with “weak” EBV HLA-II haplotypes, which prevents the control of latency I cells. Second, ectopic lymphoid structures with EBV latency form in different tissues (including the CNS), promoting inflammatory responses and further impairment of cell-mediated immunity.

Finally, immune exhaustion occurs due to chronic exposure to viral antigens, with consolidation of the disease. In the case of LC, prior to the first step, there is the possibility of previous SARS-CoV-2 infection in individuals with “weak” HLA-II haplotypes against this virus and/or EBV.

Source: Ruiz-Pablos M, Paiva B, Zabaleta A. Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID? J Transl Med. 2023 Sep 17;21(1):633. doi: 10.1186/s12967-023-04515-7. PMID: 37718435. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04515-7 (Full text)

Severity of neurological long-COVID symptoms correlates with increased level of autoantibodies targeting vasoregulatory and autonomic nervous system receptors

Abstract:

Background: The Long-COVID syndrome constitutes a plethora of persisting symptoms with neurological disorders being the most disabling ones. The pathogenesis of Long-COVID is currently under heavy scrutiny and existing data on the role of auto-immune reaction to G-protein coupled receptors (GPCR) are conflicting.

Methods: This monocentric, cross-sectional study included patients who suffered a mild to moderate SARS-CoV-2 infection up to 12 months prior to enrollment with (n = 72) or without (n = 58) Long-COVID diagnosis according to the German S1 guideline or with no known history of SARS-CoV-2 infection (n = 70). While autoantibodies towards the vasoregulation associated Adrenergic Receptor (ADR) B1 and B2 and the CNS and vasoregulation associated muscarinic acetylcholine receptor (CHR) M3 and M4 were measured by ELISA, neurological disorders were quantified by internationally standardized questionnaires.

Results: The prevalence and concentrations of evaluated autoantibodes were significantly higher in Long-COVID compared to the 2 other groups (p = 2.1*10−9) with a significantly higher number of patients with simultaneous detection of more than one autoantibody in Long-COVID group (p = 0.0419). Importantly, the overall inflammatory state was low in all 3 groups. ARB1 and ARB2 correlated negatively CERAD Trail Marking A and B (R ≤ −0.26, p ≤ 0.043), while CHRM3 correlated positively with Chadler Fatigue Scale (R = 0.37, p = 0.0087).

Conclusions: Concentrations of autoantibodies correlates to intensity of neurological disorders including psychomotor speed, visual search, attention, and fatigue.

Source: Felix S. Seibert, Ulrik Stervbo, Lea Wiemers, Sarah Skrzypczyk, Maximillian Hogeweg, Sebastian Bertram, Julia Kurek, Moritz Anft, Timm H. Westhoff, Nina Babel. Severity of neurological long-COVID symptoms correlates with increased level of autoantibodies targeting vasoregulatory and autonomic nervous system receptors. Autoimmunity Reviews,2023, 103445, ISSN 1568-9972. https://www.sciencedirect.com/science/article/abs/pii/S1568997223001799 (Full text)

The Potential Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Post-COVID-19 Condition: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog

Abstract:

Post-COVID-19 condition (commonly known as Long COVID) is a heterogeneous clinical condition in which Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and brain fog stand out among the different clinical symptoms and syndromes. Cerebral metabolic alterations and neuroendocrine disorders seem to constitute an important part of the pathophysiology of Post-COVID-19 condition (PCC).

Given the substantial lack of specific drugs and effective therapeutic strategies, hypothalamic phospholipid liposomes, which have been on the market for several years as adjuvant therapy for cerebral metabolic alterations resulting from neuroendocrine disorders, might represent a potential option in an overall therapeutic strategy that aims to control PCC-associated symptoms and syndromes. Their pharmacological mechanisms and clinical effects strongly support their potential effectiveness in PCC. Our initial clinical experience seems to corroborate this rationale. Further controlled clinical research is warranted in order to verify this hypothesis.

Source: Menichetti F. The Potential Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Post-COVID-19 Condition: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog. J Clin Med. 2023 Aug 23;12(17):5478. doi: 10.3390/jcm12175478. PMID: 37685544; PMCID: PMC10488182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10488182/ (Full text)