Rheumatology and Long COVID: lessons from the study of fibromyalgia

Abstract:

Rheumatology, such as other subspecialties, has both a unique perspective to offer as well as an evolving role to play in the global COVID-19 pandemic. Our field has already contributed meaningfully to the development and repurposing of many of the immune-based therapeutics which are now standard treatments for severe forms of the disease as well as to the understanding of the epidemiology, risk factors and natural history of COVID-19 in immune-mediated inflammatory diseases. Still in evolution is our potential to contribute to burgeoning research efforts in the next phase of the pandemic: the syndrome of postacute sequelae of COVID-19 or Long COVID. While our field brings many assets to the study of Long COVID including our expertise in the investigation of chronic inflammation and autoimmunity, our Viewpoint focuses on the strong similarities between fibromyalgia (FM) and Long COVID. While one can speculate on how embracing and confident practising rheumatologists already are regarding these interrelationships, we assert that in the emerging field of Long COVID the potential lessons from the field of fibromyalgia care and research have been underappreciated and marginalised and most importantly now deserve a critical appraisal.

Source: Clauw DJ, Calabrese L. Rheumatology and Long COVID: lessons from the study of fibromyalgia. Ann Rheum Dis. 2023 May 25:ard-2023-224250. doi: 10.1136/ard-2023-224250. Epub ahead of print. PMID: 37230736. https://ard.bmj.com/content/early/2023/05/24/ard-2023-224250 (Full text)

Identifying Demographic Trends in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients Presenting with Fibromyalgia as a Comorbidity in the Nationwide Inpatient Sample Database

Abstract

This retrospective observational study investigates the demographic differences between Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients with and without Fibromyalgia as a comorbidity using the Nationwide Inpatient Sample database.

Results reveal significant differences in demographics, including a higher proportion of females and a younger mean age in the Fibromyalgia group. Additionally, the Fibromyalgia group had lower in-hospital mortality, higher proportion of patients discharged home or to short-term hospitals, shorter lengths of stay, and lower hospital charges.

Despite having lower Elixhauser comorbidity scores, ME/CFS patients with Fibromyalgia had higher prevalence of certain conditions.

Limitations include missing data, and further research is warranted to refine ME/CFS definitions and develop personalized treatment plans. The study highlights the need for better understanding of ME/CFS mechanisms, correlations with comorbidities like Fibromyalgia, and potential predictors to improve diagnosis and treatment.

Source: Arvind Vishnu Murali. Identifying Demographic Trends in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients Presenting with Fibromyalgia as a Comorbidity in the Nationwide Inpatient Sample Database. Icahn School of Medicine at Mount Sinai ProQuest Dissertations Publishing,  2023. 30494377. https://www.proquest.com/openview/12cb80c96056a220f9e1d8bd7ea5fecc/1?pq-origsite=gscholar&cbl=18750&diss=y

Influence of Chronic Fatigue Syndrome Codiagnosis on the Relationship between Perceived and Objective Psychoneuro-Immunoendocrine Disorders in Women with Fibromyalgia

Abstract:

Although the predominant symptom in fibromyalgia (FM) is muscle pain, and fatigue in chronic fatigue syndrome (CFS), differential diagnosis is very difficult. This research investigates the psychoneuroimmunoendocrine disorders of FM patients and ascertains whether a previous CFS diagnosis affected them.

Through accelerometry objective parameters, physical activity/sedentarism levels in relation to fatigue are studied, as well as whether perceived levels of stress, anxiety, and pain correspond to objective biomarkers, all of these with respect to a reference group (RG) of women without FM.

FM patients have a worse psychological state and perceived quality of life than those with RG. These perceived outcomes are consistent with impaired objective levels of a sedentary lifestyle, higher systemic levels of cortisol and noradrenaline, and lower levels of serotonin.

However, FM patients with a previous CFS diagnosis had lower systemic levels of IL-8, cortisol, oxytocin, and higher levels of adrenaline and serotonin than FM patients without diagnosed CFS.

In conclusion, while perceived health parameters do not detect differences, when objective neuroimmunoendocrine parameters related to stress, inflammation, pain, and fatigue are used, people with CFS could be overdiagnosed with FM. This reinforces the need for objective biomarker assessment of these patients for better diagnostic discrimination between both syndromes.

Source: Otero E, Gálvez I, Ortega E, Hinchado MD. Influence of Chronic Fatigue Syndrome Codiagnosis on the Relationship between Perceived and Objective Psychoneuro-Immunoendocrine Disorders in Women with Fibromyalgia. Biomedicines. 2023; 11(5):1488. https://doi.org/10.3390/biomedicines11051488 https://www.mdpi.com/2227-9059/11/5/1488 (Full text)

Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia

Abstract:

Fibromyalgia is a debilitating widespread chronic pain syndrome that occurs in 2 to 4% of the population. The prevailing view that fibromyalgia results from central nervous system dysfunction has recently been challenged with data showing changes in peripheral nervous system activity.

Using a mouse model of chronic widespread pain through hyperalgesic priming of muscle, we show that neutrophils invade sensory ganglia and confer mechanical hypersensitivity on recipient mice, while adoptive transfer of immunoglobulin, serum, lymphocytes, or monocytes has no effect on pain behavior.

Neutrophil depletion abolishes the establishment of chronic widespread pain in mice. Neutrophils from patients with fibromyalgia also confer pain on mice. A link between neutrophil-derived mediators and peripheral nerve sensitization is already established. Our observations suggest approaches for targeting fibromyalgia pain via mechanisms that cause altered neutrophil activity and interactions with sensory neurons.

Source: Caxaria S, Bharde S, Fuller AM, Evans R, Thomas B, Celik P, Dell’Accio F, Yona S, Gilroy D, Voisin MB, Wood JN, Sikandar S. Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia. Proc Natl Acad Sci U S A. 2023 Apr 25;120(17):e2211631120. doi: 10.1073/pnas.2211631120. Epub 2023 Apr 18. PMID: 37071676. https://www.pnas.org/doi/10.1073/pnas.2211631120 (Full text)

Efficacy of Low-Dose Naltrexone and Predictors of Treatment Success or Discontinuation in Fibromyalgia and Other Chronic Pain Conditions: A Fourteen-Year, Enterprise-Wide Retrospective Analysis

Abstract:

Current pharmacologic treatments may provide limited analgesia in fibromyalgia and other chronic pain disorders. Low-dose naltrexone (LDN) has emerged as a potential analgesic option that has been minimally explored.

This study aims to describe current real-world prescribing practices of LDN, to investigate if patients have a perceived benefit of LDN in treating pain symptoms and to identify predictors associated with a perceived benefit or discontinuation of LDN.

We evaluated all outpatient prescriptions for LDN prescribed for any pain indication in the Mayo Clinic Enterprise from 1 January 2009 to 10 September 2022. A total of 115 patients were included in the final analysis.

The patients were 86% female, had a mean age of 48 ± 16 years, and 61% of prescriptions were for fibromyalgia-related pain. The final daily dose of oral LDN ranged from 0.8 to 9.0 mg, while the most common dose was 4.5 mg once daily.

Of patients who reported follow-up data, 65% reported benefit in their pain symptoms while taking LDN. Adverse effects were reported in 11 (11%) patients and 36% discontinued taking LDN by the most recent follow-up.

Concomitant analgesic medications were used by 60% of patients and were not associated with perceived benefit nor discontinuation of LDN, including concomitant opioids.

LDN is a relatively safe pharmacologic option that may benefit patients with chronic pain conditions and warrants further investigation in a prospective, controlled, and well-powered randomized clinical trial.

Source: Driver CN, D’Souza RS. Efficacy of Low-Dose Naltrexone and Predictors of Treatment Success or Discontinuation in Fibromyalgia and Other Chronic Pain Conditions: A Fourteen-Year, Enterprise-Wide Retrospective Analysis. Biomedicines. 2023; 11(4):1087. https://doi.org/10.3390/biomedicines11041087 https://www.mdpi.com/2227-9059/11/4/1087 (Full text)

Synbiotic Supplementation Improves Quality of Life and Inmunoneuroendocrine Response in Patients with Fibromyalgia: Influence of Codiagnosis with Chronic Fatigue Syndrome

Abstract:

Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are two medical conditions in which pain, fatigue, immune/inflammatory dysregulation, as well as various mental health disorders predominate in the diagnosis, without evidence of a clear consensus on the treatment of FM and CFS.
The main aim of this research was to analyse the possible effects of a synbiotic (Synbiotic, Gasteel Plus® (Heel España S.A.U.), through the study of pro-inflammatory/anti-inflammatory cytokines (IL-8/IL-10) and neuroendocrine biomarkers (cortisol and DHEA), in order to evaluate the interaction between inflammatory and stress responses mediated by the cytokine-HPA (hypothalamic-pituitary-adrenal) axis, as well as mental and physical health using body composition analysis, accelerometry and previously validated questionnaires.
The participants were women diagnosed with FM with or without a diagnostic of CFS. Each participant was evaluated at baseline and after the intervention, which lasted one month. Synbiotic intervention decreased levels of perceived stress, anxiety and depression, as well as improved quality of life during daily activities. In addition, the synbiotic generated an activation of HPA axis (physiological cortisol release) that can compensate the increased inflammatory status (elevated IL-8) observed at baseline in FM patients. There were no detrimental changes in body composition or sleep parameters, as well as in the most of the activity/sedentarism-related parameters studied by accelerometry.
It is concluded that synbiotic nutritional supplements can improve the dysregulated immunoneuroendocrine interaction involving inflammatory and stress responses in women diagnosed with FM, particularly in those without a previous CFS diagnostic; as well as their perceived of levels stress, anxiety, depression and quality of life.
Source: Hinchado MD, Quero-Calero CD, Otero E, Gálvez I, Ortega E. Synbiotic Supplementation Improves Quality of Life and Inmunoneuroendocrine Response in Patients with Fibromyalgia: Influence of Codiagnosis with Chronic Fatigue Syndrome. Nutrients. 2023; 15(7):1591. https://doi.org/10.3390/nu15071591 https://www.mdpi.com/2072-6643/15/7/1591 (Full text)

Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study

Abstract:

Previous studies showed that people with Fibromyalgia (FM) suffer from dysautonomia. Dysautonomia consists of persistent autonomic nervous system hyperactivity at rest and hyporeactivity during stressful situations. There is evidence that parameters reflecting the complex interplay between the autonomic nervous system and the cardiovascular system during exercise can provide significant prognostic information. Therefore, this study aimed to investigate the differences between people with FM and healthy controls on heart rate variability (HRV) and salivary parameters (such as flow, protein concentration, enzymatic activities of amylase, catalase and glutathione peroxidase) in two moments: (1) at baseline, and (2) after an exercise fatigue protocol.

A total of 37 participants, twenty-one were people with fibromyalgia and sixteen were healthy controls, participated in this cross-sectional study. HRV and salivary samples were collected before and after an exercise fatigue protocol. The fatigue protocol consisted of 20 repetitions of knee extensions and flexions of the dominant leg at 180 °·s-1 (degrees per second).

Significant differences were found in the HRV (stress index, LF and HF variables) and salivary biomarkers (with a higher concentration of salivary amylase in people with FM compared to healthy controls). Exercise acute effects on HRV showed that people with FM did not significantly react to exercise. However, significant differences between baseline and post-exercise on HRV significantly induce alteration on the HRV of healthy controls. Catalase significantly increased after exercise in healthy controls whereas salivary flow significantly increased in women with FM after an exercise fatigue protocol.

Our study suggests that a higher α-amylase activity and an impaired HRV can be used as possible biomarkers of fibromyalgia, associated with a reduction in salivary flow without changes in HRV and catalase activity after a fatigue exercise protocol. More studies should be carried out in the future to evaluate this hypothesis, in order to find diagnostic biomarkers in fibromyalgia.

Source: Costa AR, Freire A, Parraca JA, Silva V, Tomas-Carus P, Villafaina S. Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study. Diagnostics (Basel). 2022 Sep 14;12(9):2220. doi: 10.3390/diagnostics12092220. PMID: 36140620; PMCID: PMC9497903. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9497903/ (Full text)

The Behavior of Muscle Oxygen Saturation, Oxy and Deoxy Hemoglobin during a Fatigue Test in Fibromyalgia

Abstract:

Previous studies have reported that people with fibromyalgia (FM) could suffer from mitochondrial dysfunction. However, the consumption of muscle oxygen during physical exercise has been poorly studied. Therefore, this study aimed to explore the response of muscle oxygen during a fatigue protocol in people with FM and healthy controls (HC). In addition, the peak torque and the total work were assessed.

A total of 31 participants (eighteen were people with fibromyalgia and thirteen were healthy controls) were enrolled in this cross-sectional study. All the participants underwent a fatigue protocol consisting of 20 repetitions at 180°·s−1 of quadriceps flexions and extensions using a Biodex System 3. The muscle oxygen saturation (SmO2), total hemoglobin (THb), deoxygenated hemoglobin (HHb) and oxygenated hemoglobin (O2Hb) values were measured using a portable near-infrared spectroscopy (NIRS) device. Significant differences between people with FM and healthy controls were found at baseline: SmO2 (FM: 56.03 ± 21.36; HC: 77.41 ± 10.82; p = 0.036), O2Hb (FM: 6.69 ± 2.59; HC: 9.37 ± 1.31; p = 0.030) and HHb (FM: 5.20 ± 2.51; HC: 2.73 ± 1.32; p = 0.039); during the fatigue protocol: SmO2 (FM: 48.54 ± 19.96; HC: 58.87 ± 19.72; p = 0.038), O2Hb (FM: 5.70 ± 2.34; HC: 7.06 ± 2.09; p = 0.027) and HHb (FM: 5.69 ± 2.65; HC: 4.81 ± 2.39; p = 0.048); and in the recovery at three min and six min for SmO2, O2Hb and HHb (p < 0.005).

Furthermore, healthy control values of SmO2, O2Hb and HHb have been significantly altered by the fatigue protocol (p < 0.005). In contrast, people with FM did not show any significant alteration in these values. Moreover, significant differences were found in the peak torque at extension (FM: 62.48 ± 24.45; HC: 88.31 ± 23.51; p = 0.033) and flexion (FM: 24.16 ± 11.58; HC: 42.05 ± 9.85; p = 0.010), and the total work performed at leg extension (FM: 1039.78 ± 434.51; HC: 1535.61 ± 474.22; p = 0.007) and flexion (FM: 423.79 ± 239.89; HC: 797.16 ± 194.37; p = 0.005).

Source: Villafaina S, Tomas-Carus P, Silva V, Costa AR, Fernandes O, Parraca JA. The Behavior of Muscle Oxygen Saturation, Oxy and Deoxy Hemoglobin during a Fatigue Test in Fibromyalgia. Biomedicines. 2023 Jan 4;11(1):132. doi: 10.3390/biomedicines11010132. PMID: 36672640; PMCID: PMC9856161. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9856161/ (Full text)

Could the fibromyalgia syndrome be triggered or enhanced by COVID-19?

Abstract:

Fibromyalgia (FM) is a complex disease with an uncertain aetiology and intricate pathophysiology. Although its genesis is not fully explained, potential environmental factors, such as viral infections might trigger FM or worsen patients’ clinical outcomes.

The SARS-CoV-2 virus may affect central and peripheral nervous systems, leading to musculoskeletal, neurological, and psychological disturbances. These symptoms might persist at least 12 months beyond the recovery, often referred to as post-COVID syndrome, which resembles FM syndrome. In this sense, we argued the potential consequences of COVID-19 exclusively on FM syndrome.

First, we have described post-COVID syndrome and its painful symptoms. Afterwards, we argued whether FM syndrome could be triggered or enhanced by COVID-19 infection or by numerous and persistent stressors imposed daily by the pandemic setting (isolation, uncertainty, depression, mental stress, generalized anxiety, and fear of the virus). In addition, we have demonstrated similarities between pathophysiological mechanisms and cardinal symptoms of FM and COVID-19, speculating that SARS-CoV-2 might represent a critical mediator of FM or an exacerbator of its symptoms once both syndromes share similar mechanisms and complaints.

Therefore, pharmacologic and non-pharmacological approaches commonly used to treat FM could serve as strategic therapies to attenuate painful and neurological manifestations of post-COVID syndrome. Although it is still theoretical, clinicians and researchers should be alert of patients who develop symptoms similar to FM or those who had their FM symptoms increased post-COVID to manage them better.

Source: Fialho MFP, Brum ES, Oliveira SM. Could the fibromyalgia syndrome be triggered or enhanced by COVID-19? Inflammopharmacology. 2023 Feb 27:1–19. doi: 10.1007/s10787-023-01160-w. Epub ahead of print. PMID: 36849853; PMCID: PMC9970139. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970139/ (Full text)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study

Summary:

Background: Persistent fatigue is a common complaint in ANCA-vasculitis (AAV) patients and has a profound impact on patient’s quality of life. The symptoms associated with this fatigue mirror those found in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia. Etiologic and pathophysiologic differences exist between PR3- and MPO-ANCA disease, yet differences in their fatigue manifestations have not been well researched. We compared fatigue and its associations in healthy controls, AAV patients and fibromyalgia controls.

Methods: The Canadian consensus criteria were used for ME/CFS diagnosis, and American College of Rheumatology criteria for fibromyalgia diagnosis. Factors such as cognitive failure, depression, anxiety, and sleep disturbances were assessed by patient reported questionnaires. Clinical factors such as BVAS, vasculitis damage index, CRP and BMI were also collected.

Findings: Our AAV cohort comprised 52 patients, with a mean age of 44.7 (20–79), 57% (30/52) of the patients were female. We found 51.9% (27/52) of patients fulfilled the diagnostic criteria for ME/CFS, with 37% (10/27) of those having comorbid fibromyalgia. Rates of fatigue were higher in MPO-ANCA patients, than in PR3-ANCA patients, and their symptoms were more similar to the fibromyalgia controls. Fatigue in PR3-ANCA patients was related to inflammatory markers. These differences may be due to the varied pathophysiology of the PR3- and MPO-ANCA serotypes.

Interpretation: A large proportion of AAV patients suffer from debilitating fatigue consequential enough to meet the diagnostic criteria for ME/CFS. Fatigue associations were not the same between PR3- and MPO-ANCA patients, suggesting that the underlying mechanisms may be different. Future studies should consider ANCA serotype, as further research may inform different clinical treatment strategies for AAV patients suffering from ME/CFS.

Source: Charmaine van Eeden, Naima Mohazab, Desiree Redmond, Elaine Yacyshyn, Alison Clifford, Anthony S. Russell, Mohammed S. Osman, and Jan Willem Cohen Tervaer. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study. The Lancet Regional Health – Americas 2023;20: 100460.  https://www.thelancet.com/journals/lanam/article/PIIS2667-193X(23)00034-0/fulltext# (Full text)