Physiological assessment of orthostatic intolerance in chronic fatigue syndrome

Abstract:

Background: Orthostatic intolerance-OI is common in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-ME/CFS. We used a 10-min passive vertical lean test as orthostatic challenge-OC and measured changes in vitals and end tidal CO2 (eTCO2). An abnormal physiologic response to OC was identified in 60% of the 63 patients evaluated from one to three times over several years. Hypocapnia, either resting or induced by OC, was the most frequent abnormality, followed by postural orthostatic tachycardia.

Objective: Evaluate the physiologic response of patients with ME/CFS to a standardized OC.

Design: Respiratory and heart rate, blood pressure and eTCO2 were recorded twice at the end of 10-min supine rest and then every minute during the 10-min lean. Hypocapnia was eTCO2 ≤ 32 mmHg. Orthostatic tachycardia was heart rate increase ≥ 30 beats per minute compared with resting or ≥ 120 BPM. Orthostatic hypotension was decreased systolic pressure ≥ 20 mmHg from baseline. Tachypnea was respiratory rate of ≥ 20 breaths per minute-either supine or leaning. Questionnaire data on symptom severity, quality of life and mood were collected at visit #2.

Patients: 63 consecutive patients fulfilling the 1994 case definition for CFS underwent lean testing at first visit and then annually at visit 2 (n = 48) and 3 (n = 29).

Measures: Supine hypocapnia; orthostatic tachycardia, hypocapnia or hypotension.

Results: The majority of ME/CFS patients (60.3%, 38/63) had an abnormality detected during a lean test at any visit (51%, 50% and 45% at visits 1, 2 and 3, respectively). Hypocapnia at rest or induced by OC was more common and more likely to persist than postural orthostatic tachycardia. Anxiety scores did not differ between those with and without hypocapnia.

Conclusions: The 10-min lean test is useful in evaluation of OI in patients with ME/CFS. The most frequent abnormality, hypocapnia, would be missed without capnography.

Source: Natelson BH, Lin JS, Blate M, Khan S, Chen Y, Unger ER. Physiological assessment of orthostatic intolerance in chronic fatigue syndrome. J Transl Med. 2022 Feb 16;20(1):95. doi: 10.1186/s12967-022-03289-8. PMID: 35172863. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03289-8 (Full study)

Impaired TRPM3-dependent calcium influx and restoration using Naltrexone in natural killer cells of myalgic encephalomyelitis/chronic fatigue syndrome patients

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious disorder of unknown aetiology. While the pathomechanism of ME/CFS remains elusive, reduced natural killer (NK) cell cytotoxic function is a consistent immunological feature. NK cell effector functions rely on long-term sustained calcium (Ca2+) influx. In recent years evidence of transient receptor potential melastatin 3 (TRPM3) dysfunction supports the hypothesis that ME/CFS is potentially an ion channel disorder. Specifically, reports of single nucleotide polymorphisms, low surface expression and impaired function of TRPM3 have been reported in NK cells of ME/CFS patients. It has been reported that mu (µ)-opioid receptor (µOR) agonists, known collectively as opioids, inhibit TRPM3. Naltrexone hydrochloride (NTX), a µOR antagonist, negates the inhibitory action of µOR on TRPM3 function. Importantly, it has recently been reported that NTX restores impaired TRPM3 function in NK cells of ME/CFS patients.

Methods: Live cell immunofluorescent imaging was used to measure TRPM3-dependent Ca2+ influx in NK cells isolated from n = 10 ME/CFS patients and n = 10 age- and sex-matched healthy controls (HC) following modulation with TRPM3-agonist, pregnenolone sulfate (PregS) and TRPM3-antaognist, ononetin. The effect of overnight (24 h) NTX in vitro treatment on TRPM3-dependent Ca2+ influx was determined.

Results: The amplitude (p < 0.0001) and half-time of Ca2+ response (p < 0.0001) was significantly reduced at baseline in NK cells of ME/CFS patients compared with HC. Overnight treatment of NK cells with NTX significantly improved TRPM3-dependent Ca2+ influx in ME/CFS patients. Specifically, there was no significance between HC and ME/CFS patients for half-time response, and the amplitude of Ca2+ influx was significantly increased in ME/CFS patients (p < 0.0001).

Conclusion: TRPM3-dependent Ca2+ influx was restored in ME/CFS patients following overnight treatment of isolated NK cells with NTX in vitro. Collectively, these findings validate that TRPM3 loss of function results in altered Ca2+ influx supporting the growing evidence that ME/CFS is a TRP ion channel disorder and that NTX provides a potential therapeutic intervention for ME/CFS.

Source: Eaton-Fitch N, Du Preez S, Cabanas H, Muraki K, Staines D, Marshall-Gradisnik S. Impaired TRPM3-dependent calcium influx and restoration using Naltrexone in natural killer cells of myalgic encephalomyelitis/chronic fatigue syndrome patients. J Transl Med. 2022 Feb 16;20(1):94. doi: 10.1186/s12967-022-03297-8. PMID: 35172836. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03297-8  (Full text)

Implication of COVID-19 on Erythrocytes Functionality: Red Blood Cell Biochemical Implications and Morpho-Functional Aspects

Abstract:

Several diseases (such as diabetes, cancer, and neurodegenerative disorders) affect the morpho-functional aspects of red blood cells, sometimes altering their normal metabolism. In this review, the hematological changes are evaluated, with particular focus on the morphology and metabolic aspects of erythrocytes. Changes in the functionality of such cells may, in fact, help provide important information about disease severity and progression. The viral infection causes significant damage to the blood cells that are altered in size, rigidity, and distribution width. Lower levels of hemoglobin and anemia have been reported in several studies, and an alteration in the concentration of antioxidant enzymes has been shown to promote a dangerous state of oxidative stress in red blood cells.
Patients with severe COVID-19 showed an increase in hematological changes, indicating a progressive worsening as COVID-19 severity progressed. Therefore, monitored hematological alterations in patients with COVID-19 may play an important role in the management of the disease and prevent the risk of a severe course of the disease. Finally, monitored changes in erythrocytes and blood, in general, may be one of the causes of the condition known as Long COVID.
Source: Russo A, Tellone E, Barreca D, Ficarra S, Laganà G. Implication of COVID-19 on Erythrocytes Functionality: Red Blood Cell Biochemical Implications and Morpho-Functional Aspects. International Journal of Molecular Sciences. 2022; 23(4):2171. https://doi.org/10.3390/ijms23042171 https://www.mdpi.com/1422-0067/23/4/2171/htm (Full text)

FEATURE: Reduced brain function, immune disorder a possibility of “long COVID”

What happens to the body of a person who suffers from the long-term effects of the novel coronavirus?

A 33-year-old reporter for Kyodo News, my ailments related to COVID-19 continue to this day, more than a year after I recovered from the initial viral infection. Although I have seen slight improvements through treatment, I am still far from my former self.

In January, after an examination at the National Center of Neurology and Psychiatry in Tokyo, I was told I might be suffering from an immune disorder and reduced brain function due to the virus.

The exam I underwent included a brain perfusion scan, a test to determine blood flow in certain regions of the brain. It involves injecting radiotracers — radioactive substances that emit tiny particles — into a vein. A special camera is then used to track how the radioactive substance spreads throughout the brain to determine which areas are most active, which is believed to be indicated by blood supply.

Read the rest of this article HERE.

Source: Sayako Akita, Kyodo News, Feb 14, 2022. https://english.kyodonews.net/news/2022/02/263518f1cd8b-feature-reduced-brain-function-immune-disorder-a-possibility-of-long-covid.html

Study points to vagus nerve dysfunction as a central pathophysiological feature of long COVID

New research to be presented at this year’s European Congress of Clinical Microbiology and Infectious Diseases (ECCMID 2022, Lisbon, 23-26 April) suggests that many of the symptoms connected to post-COVID syndrome (PCC, also known as long COVID) could be linked to the effect of the virus on the vagus nerve – one of the most important multi-functional nerves in the body. The study is by Dr Gemma Lladós and Dr Lourdes Mateu, University Hospital Germans Trias i Pujol, Badalona, Spain, and colleagues.

The vagus nerve extends from the brain down into the torso and into the heart, lungs and intestines, as well as several muscles including those involved in swallowing. As such, this nerve is responsible for a wide variety of bodily functions including controlling heart rate, speech, the gag reflex, transferring food from the mouth to the stomach, moving food through the intestines, sweating, and many others.

Read the rest of this article HERE..

Source: European Society of Clinical Microbiology and Infectious Diseases. https://www.news-medical.net/news/20220212/Study-points-to-vagus-nerve-dysfunction-as-a-central-pathophysiological-feature-of-long-COVID.aspx

Treatment of chronic fatigue syndrome from yangming meridian

Abstract:

Based on the theory of “brain-gut communication” and “heart-stomach disease simultaneously”, the thinking and method of treating chronic fatigue syndrome (CFS) from yangming meridian were discussed. CFS is related to brain and heart. Based on the analysis of meridian circulation, zangfu function and the indication characteristics of yangming meridian, the indications of yangming meridian are closely related to brain and heart, so it is proposed to start from yangming meridian and use Chinese herbs combined with acupuncture to treat CFS, including the four methods of clearing away heat and moisturizing dryness, cooling blood and removing blood stasis, promoting qi to clear the organs, and strengthening and replenishing deficiency. It has certain guiding and reference significance for clinical treatment of CFS.

Source: Xue KY, Cui J. [Treatment of chronic fatigue syndrome from yangming meridian]. Zhongguo Zhen Jiu. 2022 Feb 12;42(2):203-7. Chinese. doi: 10.13703/j.0255-2930.20210106-0001. PMID: 35152588. https://pubmed.ncbi.nlm.nih.gov/35152588/

The Female-Predominant Persistent Immune Dysregulation of the Post-COVID Syndrome

Abstract:

Objective: To describe the clinical data from the first 108 patients seen in the Mayo Clinic post-COVID-19 care clinic (PCOCC).

Methods: After Institutional Review Board approval, we reviewed the charts of the first 108 patients seen between January 19, 2021, and April 29, 2021, in the PCOCC and abstracted from the electronic medical record into a standardized database to facilitate analysis. Patients were grouped into phenotypes by expert review.

Results: Most of the patients seen in our clinic were female (75%; 81/108), and the median age at presentation was 46 years (interquartile range, 37 to 55 years). All had post-acute sequelae of SARS-CoV-2 infection, with 6 clinical phenotypes being identified: fatigue predominant (n=69), dyspnea predominant (n=23), myalgia predominant (n=6), orthostasis predominant (n=6), chest pain predominant (n=3), and headache predominant (n=1). The fatigue-predominant phenotype was more common in women, and the dyspnea-predominant phenotype was more common in men. Interleukin 6 (IL-6) was elevated in 61% of patients (69% of women; P=.0046), which was more common than elevation in C-reactive protein and erythrocyte sedimentation rate, identified in 17% and 20% of cases, respectively.

Conclusion: In our PCOCC, we observed several distinct clinical phenotypes. Fatigue predominance was the most common presentation and was associated with elevated IL-6 levels and female sex. Dyspnea predominance was more common in men and was not associated with elevated IL-6 levels. IL-6 levels were more likely than erythrocyte sedimentation rate and C-reactive protein to be elevated in patients with post-acute sequelae of SARS-CoV-2 infection.

Source: Ganesh R, Grach SL, Ghosh AK, Bierle DM, Salonen BR, Collins NM, Joshi AY, Boeder ND Jr, Anstine CV, Mueller MR, Wight EC, Croghan IT, Badley AD, Carter RE, Hurt RT. The Female-Predominant Persistent Immune Dysregulation of the Post-COVID Syndrome. Mayo Clin Proc. 2022 Feb 5:S0025-6196(21)00888-0. doi: 10.1016/j.mayocp.2021.11.033. Epub ahead of print. PMID: 35135695; PMCID: PMC8817110. https://www.sciencedirect.com/science/article/pii/S0025619621008880 (Full text)

Inappropriate sinus tachycardia in long-COVID and other updates on recent autonomic research

As the COVID-19 pandemic continues to affect hundreds of millions of people worldwide, autonomic complications are being recognized with increasing frequency in both the acute and chronic form of the illness, the latter now designated as post-acute sequelae of SARS-CoV-2 (PASC), colloquially termed long-COVID. Tachycardia is a common symptom of PASC, and some patients may be diagnosed with postural tachycardia syndrome (POTS) or inappropriate sinus tachycardia (IST). While post-COVID POTS has garnered more attention from the scientific and popular press, IST may be equally or more common and has been reported in survivors of the prior SARS coronavirus pandemic [1]. The etiology of IST is unknown; however, the proposed mechanisms overlap with those of POTS, including increased sympathetic and/or reduced cardiovagal activity.

In their recent publication [2], “Inappropriate sinus tachycardia in post-COVID-19 syndrome” Aranyo and colleagues identified 200 consecutive patients with PASC. IST was defined according to consensus criteria as symptomatic sinus rhythm rate ≥ 100 bpm at rest with a mean 24-h heart rate above 90 beats/min in the absence of any acute physiological demand or conditions known to produce sinus tachycardia. All patients underwent a 10-min active stand test to help rule out disorders of orthostatic intolerance, such as POTS and orthostatic hypotension. In addition, patients underwent an echocardiogram, 24-h Holter monitoring, a 6-min walk test (6MWT), and measurements of blood markers of inflammation and myocardial damage, including ferritin and interleukin-6. Heart rate variability (HRV) analysis was performed from the 24-h Holter data, focusing on standard time-domain parameters such as the RR interval, standard deviation of the inter-beat interval (SDNN), and the percentage of adjacent NN intervals that differed from each other by more than 50 ms (PNN50), as well as standard frequency-domain parameters including very low-frequency (VLF; 0.003–0.04 Hz), low-frequency (LF; 0.04–0.15 Hz), and high-frequency (HF; 0.15–0.40 Hz) bands. The HF band and PNN50 are regarded as indicators of the parasympathetic influence on heart rate, whereas the LF and VLF bands have more complex physiology that integrates both the sympathetic and parasympathetic components. Comparison groups included age- and gender-matched PCR-confirmed COVID patients without IST (fully recovered group, N = 19) and age- and gender-matched controls who had no history of SARS-COV-2 disease, as confirmed by negative serology (uninfected group, N = 17).

The authors identified 40 patients with IST from the cohort of 200 patients with PASC yielding an estimated prevalence of 20%. Eighty-five percent of the subjects were women and 83% had a history of mild COVID defined as the presence of symptoms without evidence of viral pneumonia or hypoxia. Most patients reported cardiopulmonary symptoms at the onset of their infection, including palpitations (90%), dyspnea (83%), and chest pain (78%); 53% reported dizziness and 48% anosmia. Compared to fully recovered patients, patients with IST were more likely to report palpitations (90% vs. 5%; p < 0.001), dyspnea (82% vs. 16%; p < 0.001), chest pain (78% vs. 21%; p < 0.001), headache (73% vs. 37%; p = 0.007), dizziness (53% vs. 5%; p = 0.002), diarrhea (53% vs. 16%; p = 0.003), and dermatological alterations (35% vs. 5%; p = 0.009) during the acute phase of SARS-CoV-2 infection. Patients with IST were also more likely to report environmental allergies compared to the fully recovered and uninfected groups (25% vs. 0%; p = 0.01), hinting at a potential mast cell component.

The 6MWT showed that patients with PASC with IST had a significantly reduced exercise capacity, with a 60% reduction in their estimated normal distance. Frequency analysis of heart rate variability revealed that patients with IST had a reduction in VLF, LF, and HF domains compared to controls, with more severe impairment in the parasympathetic-influenced domains. There was no difference in blood inflammatory markers between groups.

Limitations of this work include the small sample sizes of the control groups, as well as the lack of systematic pulmonary evaluations, measurement of markers of physical deconditioning, and systematic autonomic testing. Nonetheless, this study provides the first glimpse of how common IST may be in PASC and adds to the growing body of literature on autonomic dysfunction as a potential mechanism in PASC-related disability. With the Omicron variant currently surging across the globe, PASC-related autonomic complications will, unfortunately, be with us for some time, and clinicians should be familiar with their manifestations and potential treatment options.

Read the rest of this article HERE.

Source: Miglis MG, Larsen N, Muppidi S. Inappropriate sinus tachycardia in long-COVID and other updates on recent autonomic research. Clin Auton Res. 2022 Feb 7. doi: 10.1007/s10286-022-00854-5. Epub ahead of print. PMID: 35129713. https://link.springer.com/article/10.1007/s10286-022-00854-5 (Full text)

Prevalence of post-acute COVID-19 syndrome symptoms at different follow-up periods: A systematic review and meta-analysis

Abstract:

Background: Post-acute COVID-19 Syndrome is now recognized as a complex systemic disease that is associated with substantial morbidity.

Objectives: To estimate the prevalence of persistent symptoms and signs at least 12 weeks after acute COVID-19 at different follow-up periods.

Data sources: Searches were conducted up to October 2021 in Ovid Embase, Ovid Medline, and PubMed.

Study eligibility criteria: Articles in English that reported the prevalence of persistent symptoms among individuals with confirmed SARS-CoV-2 infection and included at least 50 patients with a follow-up of at least 12 weeks after acute illness.

Methods: Random-effect meta-analysis was performed to produce pooled prevalence for each symptom at 4 different follow-up time intervals. Between-studies heterogeneity was evaluated using the I2 statistic and was explored via meta-regression, considering several a priori study level variables. Risk of bias was assessed using the Joanna Briggs Institute (JBI) tool and the Newcastle-Ottawa Scale for prevalence studies and comparative studies, respectively.

Results: After screening 3209 studies, a total of 63 studies were eligible, with a total COVID-19 population of 257,348. The most commonly reported symptoms were fatigue, dyspnea, sleep disorder and concentration difficulty (32%, 25%, 24%, and 22% respectively at 3-<6 months follow-up), effort intolerance, fatigue, sleep disorder and dyspnea (45%, 36%, 29% and 25% respectively at 6-<9 months follow-up), fatigue (37%) and dyspnea (21%) at 9-<12 months and fatigue, dyspnea, sleep disorder, myalgia (41%, 31%, 30%, and 22% respectively at >12 months follow-up). There was substantial between-studies heterogeneity for all reported symptoms prevalence. Meta-regressions identified statistically significant effect modifiers: world region, male gender, diabetes mellitus, disease severity and overall study quality score. Five of six studies including a comparator group consisting of COVID-19 negative cases observed significant adjusted associations between COVID-19 and several long-term symptoms.

Conclusions: This systematic review found that a large proportion of patients experience PACS 3 to 12 months after recovery from the acute phase of COVD-19. However, available studies of PACS are highly heterogeneous. Future studies need to have appropriate comparator groups, standardized symptoms definitions and measurements and longer follow-up.

Source: Alkodaymi MS, Omrani OA, Fawzy NA, Shaar BA, Almamlouk R, Riaz M, Obeidat M, Obeidat Y, Gerberi D, Taha RM, Kashour Z, Kashour T, Berbari EF, Alkattan K, Tleyjeh IM. Prevalence of post-acute COVID-19 syndrome symptoms at different follow-up periods: A systematic review and meta-analysis. Clin Microbiol Infect. 2022 Feb 3:S1198-743X(22)00038-6. doi: 10.1016/j.cmi.2022.01.014. Epub ahead of print. PMID: 35124265; PMCID: PMC8812092. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8812092/ (Full text)

Long COVID Patient Fact Sheet

‘Long COVID’ is the term that is often used to describe these persistent symptoms. You are considered to have ‘Long COVID’ when you are still having symptoms at least 4 weeks after the initial infection. Long COVID may also be referred to by other names such as post-COVID conditions, PASC (post-acute sequelae of COVID-19) or long-haul COVID.

Who Could Develop Long COVID?

Researchers around the world are trying to understand why some people develop Long COVID. People of all ages have been diagnosed with long COVID, including people with no underlying health conditions. Young and otherwise healthy people, and even those with mild infections, can be affected. More research is needed on the wide range of symptoms and why some people have more severe symptoms than others.

Read the full fact sheet as a PDF file HERE.