Fibromyalgia and cytokines

Exploring levels of TSH and FT4 in patients with chronic fatigue syndrome (CFS), fibromyalgia (FM) and healthy controls did not reveal any associations between fatigue score and level of thyroid hormones

AIM

The diagnoses of Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM) are highly associated with fatigue and pain, respectively. Physiologically and clinically an effect of thyroid status on fatigue and pain is expected. There may be clinically relevant differences in thyroid hormone axes though within values of reference in both patients with normal thyroid hormones, or in patients with well-regulated thyroid disease. These potential differences are explored in this study.

MATERIALS AND METHODS

In the present study, female patients with CFS (n = 49) and FM (n = 58) as well as female healthy controls (n = 53) were included. We explored plasma levels of TSH and FT4 between the groups using Kruskall-Wallis, and the relation between fatigue score and levels of TSH and FT4 by means of Spearman's rho.

RESULTS

There were no group differences between CFS patients, FM patients, and healthy controls in levels of TSH and FT4.

CONCLUSION

As one might clinically and physiologically expect an association between thyroid function and fatigue, which may be associated with clinical disorders such as CFS and FM, we suggest future studies to examine the field further by exploring the influence of thyroid receptors and responses of the thyroid hormone cascade.

Concomitant Treatment with Doxycycline and Rifampicin in Balb/c Mice Infected with Brucella abortus 2308 Fails to Reduce Inflammation and Motor Disability

Brucellosis is an infection widely distributed around the world, and in some countries it is considered a public health problem. Brucellosis causes insidious symptoms that make it difficult to diagnose. Infection can also trigger chronic pain and neuropsychiatric complications. Antibiotics are not always effective to eradicate infection, contributing to chronicity. We aimed to investigate the effects of antibiotic treatment on proinflammatory cytokines, neurotransmitters, corticosterone, and behavior in a murine model of infecrion of B. abortus strain 2308. Four study groups were created: (a) control; (b) antibiotic control; (c) infected with B. abortus 2308; and (d) infected and treated with rifampicin and doxycycline. We determined B. abortus 2308 colony-forming units (CFUs), the count of dendritic cells, and macrophages in the spleen; serum levels of cytokines and corticosterone; levels of serotonin, dopamine, epinephrine, and norepinephrine in the brain; and equilibrium, physical strength, anxiety, and hopelessness tests. The infected and treated mice group was compared with the control and infected mice to assess whether treatment is sufficient to recover neuroimmunoendocrine parameters. Our results showed that despite the treatment of brucellosis with rifampicin and doxycycline, antibiotic-treated mice showed a persistence of B. abortus 2308 CFUs, an increased count in macrophage number, and higher circulating levels of corticosterone. Furthermore, the levels of IL-12, IL-6, and TNF-α remained higher. We found a decrease in muscular strength and equilibrium concomitant to changes in neurotransmitters in the hippocampus, cerebellum, and frontal cortex. Our data suggest that the remaining bacterial load after antibiotic administration favors inflammatory, neurochemical, and behavioral alterations, partly explaining the widespread and paradoxical symptomatology experienced by patients with chronic brucellosis.

Frequency of fibromyalgianess in patients with rheumatoid arthritis and ankylosing spondylitis: A multicenter study of Turkish League Against Rheumatism (TLAR) network

Objectives

This study aimed to evaluate the frequency of fibromyalgianess, fibromyalgia syndrome (FS), and widespread pain in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) and their relationship with clinical and demographic parameters.

Patients and methods

This cross-sectional multicenter trial was performed in 14 centers across Türkiye between June 2018 and November 2019. Out of 685 patients recruited from the accessible population, 661 patients (342 RA, 319 AS; 264 males, 397 females; mean age: 48.1±12.9 years; range, 17 to 88 years) met the selection criteria. In these cohorts, those who did not meet the criteria for FS and had widespread pain (widespread pain index ≥7) were evaluated as a separate group. Clinical status and demographic parameters of patients in both cohorts were evaluated as well as the evaluations of RA and AS patients with widespread pain (widespread pain index ≥7) and RA and AS patients with FS groups. In addition, correlations between polysymptomatic distress scale (PSD) scores and Visual Analog Scale (VAS), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), and Disease Activity Score using 28 joint counts for RA patients and VAS, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Ankylosing Spondylitis Disease Activity Score (ASDAS) for AS patients were analyzed.

Results

Frequencies of patients with FS and patients who had PSD scores ≥12 were 34.1% and 44.4% in all RA patients, respectively. Moreover, FS and PSD scores ≥12 were found in 29.2% and 36.9% of all AS patients, respectively. PSD scores of RA patients with FS were higher than all RA patients and RA patients with widespread pain. SDAI and CDAI scores of RA patients with FS were higher than all RA patients and RA patients with widespread pain. Similarly, PSD scores of AS patients with FS were higher than all AS patients and AS patients with widespread pain. ASDAS-erythrocyte sedimentation rate and BASDAI scores of AS patients with FS were found higher than all AS patients and AS patients with widespread pain.

Conclusion

Disease activity scores, including pain in RA and AS, were higher in the presence of FS or fibromyalgianess. It may be related to clinical parameters, but cohort studies with long-term follow-up are needed to reveal causality. Additionally, to avoid overtreatment, coexistence of fibromyalgianess should be kept in mind in patients who have inflammatory diseases such as RA and AS, particularly with intractable widespread pain.

Imbalance of Th1 and Th2 Cytokines and Stem Cell Therapy in Pathological Pain

The pathophysiological importance of T helper 1 (Th1) and Th2 cell cytokines in pathological pain has been highly debated in recent decades. However, the analgesic strategy targeting individual cytokines still has a long way to go for clinical application. In this review, we focus on the contributions of Th1 cytokines (TNF-α, IFN-γ, and IL-2) and Th2 cytokines (IL-4, IL-5, IL-10, and IL-13) in rodent pain models and human pain-related diseases. A large number of studies have shown that Th1 and Th2 cytokines have opposing effects on pain modulation. The imbalance of Th1 and Th2 cytokines might determine the final effect of pain generation or inhibition. However, increasing evidence indicates that targeting the individual cytokine is not sufficient for the treatment of pathological pain. It is practical to suggest a promising therapeutic strategy against the combined effects of Th1 and Th2 cytokines. We summarize the current advances in stem cell therapy for pain-related diseases. Preclinical and clinical studies show that stem cells inhibit proinflammatory cytokines and release enormous Th2 cytokines that exhibit a strong analgesic effect. Therefore, a shift of the imbalance of Th1 and Th2 cytokines induced by stem cells will provide a novel therapeutic strategy against intractable pain. It is extremely important to reveal the cellular and molecular mechanisms of stem cell-mediated analgesia. The efficiency and safety of stem cell therapy should be carefully evaluated in animal models and patients with pathological pain.

The Role and Potential Mechanism of Complement Factor D in Fibromyalgia Development

Purpose

Fibromyalgia (FM) is a syndrome characterized by chronic musculoskeletal pain. Its clinical symptoms include both somatic and psychiatric symptoms, making the treatment of FM extremely challenging. The cause of FM is still unknown, and some patients do not improve their symptoms even after long-term active treatment. Thus, the development of new targeted therapies is important to reduce pain and improve quality of life for FM patients.

Methods

In this study, we screened genes and secreted factors that play key roles in FM through bioinformatics and big data analysis. Furthermore, we performed CCK-8, qRT-PCR, glucose, ATP and lactate content testing, dual luciferase reporter gene assay to investigate the potential mechanism of complement factor D in fibromyalgia development.

Results

In bioinformatics and big data analysis, we identified CFD was negatively correlated with the pro-inflammatory factor IL-6 and positively correlated with the anti-inflammatory factor IL-4, which suggested that CFD may be an anti-inflammatory factor. Through cellular assays, we verified that CFD reversed the decrease in IL-4 expression and the increase in IL-6 expression in BV2 cells caused by ATP.

Conclusion

In summary, based on bioinformatic methods and big data mining we obtained a new target CFD for FM, and further experiments verified that CFD has significant inhibition of ATP-induced neuropathic pain. These findings provide a new theoretical basis for the clinical translation of CFD.

Altered response to Toll-like receptor 4 activation in fibromyalgia: A low-dose, human experimental endotoxemia pilot study

In this pilot study, a human intravenous injection of low-dose endotoxin (lipopolysaccharide, LPS) model was used to test if fibromyalgia is associated with altered immune responses to Toll-like receptor 4 (TLR4) activation. Eight women with moderately-severe fibromyalgia and eight healthy women were administered LPS at 0.1 ng/kg in session one and 0.4 ng/kg in session two. Blood draws were collected hourly to characterize the immune response. The primary analytes of interest, leptin and fractalkine, were assayed via commercial radioimmunoassay and enzyme-linked immunosorbent assay kits, respectively. Exploratory analyses were performed on 20 secreted cytokine assays by multiplex cytokine panels, collected hourly. Exploratory analyses were also performed on testosterone, estrogen, and cortisol levels, collected hourly. Additionally, standard clinical complete blood counts with differential (CBC-D) were collected before LPS administration and at the end of the session. The fibromyalgia group demonstrated enhanced leptin and suppressed fractalkine responses to LPS administration. In the exploratory analyses, the fibromyalgia group showed a lower release of IFN-γ, CXCL10, IL-17A, and IL-12 and higher release of IL-15, TARC, MDC, and eotaxin than the healthy group. The results of this study suggest that fibromyalgia may involve an altered immune response to TLR4 activation.

The Effects of Non-Pharmacological Interventions in Fibromyalgia: A Systematic Review and Metanalysis of Predominants Outcomes

(1) Fibromyalgia (FM) is a chronic musculoskeletal condition with multiple symptoms primarily affecting women. An imbalance in cytokine levels has been observed, suggesting a chronic low-grade inflammation. The main aim of the meta-analysis was to examine the effect of multimodal rehabilitation on cytokine levels and other predominant variables in patients with FM. Furthermore, to examine which non-pharmacological tools have been used to investigate the effects that these can have on cytokines in FM patients. (2) Methods: Searches were conducted in PubMed, Scopus, Web of Science, Cochrane, and ScienceDirect databases. This systematic review and metanalysis followed the PRISMA statement protocol. The methodological quality of the studies was assessed using the PEDro scale, the risk of bias followed the Cochrane Manual 5.0.1, and the GRADE system was used for rating the certainty of evidence. (3) Results: Of 318 studies found, eight were finally selected, with a sample size of 320 women with a mean age of 57 ± 20. The proinflammatory cytokines IL-1β, IL-6, IL-8 and TNF-α were the most studied. Resistance exercise, aquatic exercise, dynamic contractions, cycling, treadmill, and infrared therapy were the main non-pharmacological tools used. (4) Conclusions: The systematic review with meta-analysis found evidence of elevated cytokine levels in patients with FM, suggesting low chronic inflammation and a possible contribution to central sensitization and chronic pain. However, the effects of physiotherapeutic interventions on cytokine levels are variable, highlighting the importance of considering different factors and the need for further research.

Can the monocyte-to-HDL ratio be used as an inflammation marker in patients with fibromyalgia syndrome?

Background and Aim

The monocyte-to-high-density lipoprotein (HDL) ratio (MHR) may be used as a marker of inflammation and oxidative stress. This study aimed to evaluate the use of MHR and platelet markers in patients with fibromyalgia syndrome (FMS) and demonstrate MHR's relationship with inflammation, the Fibromyalgia Impact Questionnaire (FIQ), and quality of life.

Materials and Methods

Ninety FMS patients and 90 healthy controls, whose clinical and laboratory evaluations were performed simultaneously, were included in the study. The monocyte, platelet, HDL, MHR, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), mean platelet volume (MPV), and platelet distribution width (PDW) values of all patients were evaluated. The quality of life of the participants was assessed using the FIQ and their general health using the health assessment questionnaire (HAQ).

Results

Age, body mass index (BMI), and marital status distribution were similar in both groups. The FMS patients had a mean disease duration of 11.29 ± 2.62 months. The median monocyte, platelet, MPV, visual analog scale (VAS), FIQ, and HAQ values and the mean MHR of the FMS patients were significantly higher than the control group, while the mean HDL level was significantly lower (P < 0.05). There was a weak negative correlation between the MPV and HAQ score and the PDW and HAQ score (rs = -0.225, P = 0.042 and rs = -0.249, P = 0.024, respectively), whereas no correlation was detected between the MHR and the FIQ and HAQ scores in FMS patients. According to the receiver operating characteristic curve analysis, MHR had prediction of FMS (P = 0.002; sensitivity = 0.63, specificity = 0.50, cut-off point ≥8.4).

Conclusions

Our results suggest that the monocyte, platelet, HDL, MHR, and MPV parameters can be used in the evaluation of inflammation in FMS patients.

The immunomodulatory effects of ethosuximide and sodium butyrate on experimentally induced fibromyalgia: The interaction between IL-4, synaptophysin, and TGF-β1/NF-κB signaling

BACKGROUND AND AIMS

Fibromyalgia is a widespread chronic pain syndrome associated with several comorbid conditions that affect the quality of patients' life. Its pathogenesis is complex, and the treatment strategies are limited by partial efficacy and potential adverse effects. So, our aim was to investigate the possible ameliorative effects of ethosuximide and sodium butyrate on fibromyalgia and compare their effects to pregabalin.

MATERIALS AND METHODS

In a mouse model of reserpine induced fibromyalgia, the effect of ethosuximide, sodium butyrate, and pregabalin was investigated. Evaluation of mechanical allodynia, cold hypersensitivity, anxiety, cognitive impairment, and depression was performed. Also, the brain and spinal cord tissue serotonin, dopamine and glutamate in addition to the serum levels of interleukin (IL)-4 and transforming growth factor beta 1 (TGF-β1) were assayed. Moreover, the expression of nuclear factor kappa B (NF-κB) synaptophysin was immunoassayed in the hippocampal tissues.

KEY FINDINGS

Ethosuximide and sodium butyrate restored the behavioral tests to the normal values except for the antidepressant effect which was evident only with ethosuximide. Both drugs elevated the levels of the anti-inflammatory cytokines IL-4 and TGF-β1, reduced the hippocampal NF-κB, and increased synaptophysin expression with superiority of sodium butyrate. Ethosuximide reduced only spinal cord and brain glutamate while improved brain dopamine while sodium butyrate elevated spinal cord dopamine and serotonin with no effect on glutamate. Also, sodium butyrate elevated brain serotonin and reduced glutamate with no effect on brain dopamine.

SIGNIFICANCE

Each of sodium butyrate and ethosuximide would serve as a promising therapeutic modality for management of fibromyalgia and its comorbid conditions.

Individual Heterogeneity in the Relations Between Sleep, Inflammation, and Somatic Symptoms

OBJECTIVE

Poor sleep is associated with the experience of more somatic symptoms and a proinflammatory state, whereas a proinflammatory state may also result in the experience of more somatic symptoms. However, existing studies ignore individual differences in these associations. We aimed to study relations between sleep, inflammatory markers, and somatic symptoms at a within-individual level.

METHODS

Time series of daily data on sleep, somatic symptoms, and inflammation markers in 10 healthy individuals (age, 19-58 years; three men) for 63 days were analyzed. Bidirectional lagged ( t - 1) and contemporaneous ( t ) relations between sleep duration, inflammatory markers (C-reactive protein, interferon-α, interleukin 1RA), and somatic symptoms were analyzed using 24-hour urine and diary data. Unified structural equation modeling was used to analyze the association between sleep duration, the three inflammatory markers, and the amount of somatic symptoms at the individual level.

RESULTS

Associations were found between sleep and at least one of three inflammatory markers in four individuals, both positive (three associations) and negative (five associations) and contemporaneous (four associations) and lagged (four associations). Sleep was related to somatic symptoms in four individuals, both positive ( n = 2) and negative ( n = 2) and contemporaneous ( n = 3) and lagged ( n = 1). Inflammatory markers were associated with somatic symptoms in three individuals, both positive (three associations) and negative (one association) and contemporaneous (three associations) and lagged (one associations). Two individuals showed no associations between sleep, inflammatory markers, and somatic symptoms.

CONCLUSIONS

We observed a large variability in presence, strength, and direction of associations between sleep, inflammatory markers, and somatic symptoms.

Analysis of the Influence of IL-6 and the Activation of the Jak/Stat3 Pathway in Fibromyalgia

Background: Fibromyalgia is a medical condition that affects a small percentage of the population, with no known effective treatment. There is evidence to suggest that inflammation is a key factor in the nerve sensitization that characterizes the disorder. Therefore, this paper concentrates on the role of IL-6 in fibromyalgia and the related pain-like symptoms. Methods: This work aimed to evaluate Sprague–Dawley rats, which were injected for three consecutive days with 1 mg/kg of reserpine; IL-6-R Ab was intraperitoneally injected at 1.5 mg/kg seven days after the first reserpine injection. Behavioral analyses were conducted at the beginning of the experiment and at seven and twenty-one days from the first reserpine injection. At this timepoint, the animals were sacrificed, and tissues were collected for molecular and histological analysis. Results: Our data showed the analgesic effect of IL-6-R-Ab administration on mechanical allodynia and thermal hyperalgesia. Additionally, the reserpine + IL-6-R-Ab group showed a reduced expression of the pain-related mediators cFOS and NFG and reduced levels of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and chemokines (Cxcl5, Cxcl10 and Cx3cl1). From the molecular point of view, the IL-6-R-Ab administration reduced the gp130 phosphorylation and the activation of the Jak/STAT3 pathway. Additionally, the IL-6-R Ab reduced the activation of neuroinflammatory cells. Conclusions: Our study showed that IL-6 plays a crucial role in fibromyalgia by triggering the Jak/STAT3 pathway, leading to an increase in chemokine levels and activating glial cells.

RNA regulation of inflammatory responses in glia and its potential as a therapeutic target in central nervous system disorders

A major hallmark of neuroinflammation is the activation of microglia and astrocytes with the induction of inflammatory mediators such as IL-1β, TNF-α, iNOS, and IL-6. Neuroinflammation contributes to disease progression in a plethora of neurological disorders ranging from acute CNS trauma to chronic neurodegenerative disease. Posttranscriptional pathways of mRNA stability and translational efficiency are major drivers for the expression of these inflammatory mediators. A common element in this level of regulation centers around the adenine- and uridine-rich element (ARE) which is present in the 3' untranslated region (UTR) of the mRNAs encoding these inflammatory mediators. (ARE)-binding proteins (AUBPs) such as Human antigen R (HuR), Tristetraprolin (TTP) and KH- type splicing regulatory protein (KSRP) are key nodes for directing these posttranscriptional pathways and either promote (HuR) or suppress (TTP and KSRP) glial production of inflammatory mediators. This review will discuss basic concepts of ARE-mediated RNA regulation and its impact on glial-driven neuroinflammatory diseases. We will discuss strategies to target this novel level of gene regulation for therapeutic effect and review exciting preliminary studies that underscore its potential for treating neurological disorders.

Circulating microRNA expression signatures accurately discriminate myalgic encephalomyelitis from fibromyalgia and comorbid conditions

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and fibromyalgia (FM) are two chronic complex diseases with overlapping symptoms affecting multiple systems and organs over time. Due to the absence of validated biomarkers and similarity in symptoms, both disorders are misdiagnosed, and the comorbidity of the two is often unrecognized. Our study aimed to investigate the expression profiles of 11 circulating miRNAs previously associated with ME/CFS pathogenesis in FM patients and individuals with a comorbid diagnosis of FM associated with ME/CFS (ME/CFS + FM), and matched sedentary healthy controls. Whether these 11 circulating miRNAs expression can differentiate between the two disorders was also examined. Our results highlight differential circulating miRNAs expression signatures between ME/CFS, FM and ME/CFS + FM, which also correlate to symptom severity between ME/CFS and ME/CFS + FM groups. We provided a prediction model, by using a machine-learning approach based on 11 circulating miRNAs levels, which can be used to discriminate between patients suffering from ME/CFS, FM and ME/CFS + FM. These 11 miRNAs are proposed as potential biomarkers for discriminating ME/CFS from FM. The results of this study demonstrate that ME/CFS and FM are two distinct illnesses, and we highlight the comorbidity between the two conditions. Proper diagnosis of patients suffering from ME/CFS, FM or ME/CFS + FM is crucial to elucidate the pathophysiology of both diseases, determine preventive measures, and establish more effective treatments.

Physical properties and biological effects of ceramic materials emitting infrared radiation for pain, muscular activity, and musculoskeletal conditions

BACKGROUND

Up to 33% of the general population worldwide suffer musculoskeletal conditions, with low back pain being the single leading cause of disability globally. Multimodal therapeutic options are available to relieve the pain associated with muscular disorders, including physical, complementary, and pharmacological therapies. However, existing interventions are not disease modifying and have several limitations.

METHOD

Literature review.

RESULTS

In this context, the use of nonthermal infrared light delivered via patches, fabrics, and garments containing infrared-emitting bioceramic minerals have been investigated. Positive effects on muscular cells, muscular recovery, and reduced inflammation and pain have been reported both in preclinical and clinical studies. There are several hypotheses on how infrared may contribute to musculoskeletal pain relief, however, the full mechanism of action remains unclear. This article provides an overview of the physical characteristics of infrared radiation and its biological effects, focusing on those that could potentially explain the mechanism of action responsible for the relief of musculoskeletal pain.

CONCLUSIONS

Based on the current evidence, the following pathways have been considered: upregulation of endothelial nitric oxide synthase, increase in nitric oxide bioavailability, anti-inflammatory effects, and reduction in oxidative stress.

A Link Between Inflammatory Mechanisms and Fibromyalgia

Fibromyalgia (FM) is a condition characterized by chronic widespread pain, which has traditionally been considered psychogenic in nature due to lack of known underlying organic pathophysiology. In more recent years, inflammation of the nervous system has become increasingly recognized as a sign of neuropsychiatric conditions, and this association may enhance our knowledge of conditions such as FM. Emerging evidence has suggested inflammation, particularly neuroinflammation, as a potential contributor underlying the etiology of FM. Studies have searched for linked biomarkers with mixed results, though the literature is beginning to point to increased systemic levels of pro-inflammatory cytokines such as IL-6 and IL-8 in patients with FM relative to healthy controls. A multicenter imaging study has also reported results suggestive of microglial activation related to the presence of FM. Given the consistency in neuroinflammatory effects implicated in "sickness behavior" characteristic of chronic systemic inflammatory conditions such as cancer or rheumatic diseases, therein springs the hypothesis for a connection between FM and neuroinflammation as discussed in this chapter.

Effectiveness, cost-utility and physiological underpinnings of the FIBROWALK multicomponent therapy in online and outdoor format in individuals with fibromyalgia: Study protocol of a randomized, controlled trial (On&Out study)

Introduction: The On&amp;Out study is aimed at assessing the effectiveness, cost-utility and physiological underpinnings of the FIBROWALK multicomponent intervention conducted in two different settings: online (FIBRO-On) or outdoors (FIBRO-Out). Both interventions have proved to be efficacious in the short-term but there is no study assessing their comparative effectiveness nor their long-term effects. For the first time, this study will also evaluate the cost-utility (6-month time-horizon) and the effects on immune-inflammatory biomarkers and Brain-Derived Neurotrophic Factor (BDNF) levels of both interventions. The objectives of this 6-month, randomized, controlled trial (RCT) are 1) to examine the effectiveness and cost-utility of adding FIBRO-On or FIBRO-Out to Treatment-As-Usual (TAU) for individuals with fibromyalgia (FM); 2) to identify pre–post differences in blood biomarker levels in the three study arms and 3) to analyze the role of process variables as mediators of 6-month follow-up clinical outcomes.

Methods and analysis: Participants will be 225 individuals with FM recruited at Vall d’Hebron University Hospital (Barcelona, Spain), randomly allocated to one of the three study arms: TAU vs. TAU + FIBRO-On vs. TAU + FIBRO-Out. A comprehensive assessment to collect functional impairment, pain, fatigue, depressive and anxiety symptoms, perceived stress, central sensitization, physical function, sleep quality, perceived cognitive dysfunction, kinesiophobia, pain catastrophizing, psychological inflexibility in pain and pain knowledge will be conducted pre-intervention, at 6 weeks, post-intervention (12 weeks), and at 6-month follow-up. Changes in immune-inflammatory biomarkers [i.e., IL-6, CXCL8, IL-17A, IL-4, IL-10, and high-sensitivity C-reactive protein (hs-CRP)] and Brain-Derived Neurotrophic Factor will be evaluated in 40 participants in each treatment arm (total n = 120) at pre- and post-treatment. Quality of life and direct and indirect costs will be evaluated at baseline and at 6-month follow-up. Linear mixed-effects regression models using restricted maximum likelihood, mediational models and a full economic evaluation applying bootstrapping techniques, acceptability curves and sensitivity analyses will be computed.

Ethics and dissemination: This study has been approved by the Ethics Committee of the Vall d’Hebron Institute of Research. The results will be actively disseminated through peer-reviewed journals, conference presentations, social media and various community engagement activities. Trial registration number NCT05377567 (clinicaltrials.gov).

Direct-Acting Antiviral Drugs Reduce Fibromyalgia Symptoms in Patients with Chronic Hepatitis C

Background Fibromyalgia (FM) is a complex disorder characterized by chronic widespread pain and significant patient burden. Patients with chronic hepatitis C are reportedly predisposed to the development of FM. Direct-acting antiviral drugs (DAA) achieved a remarkable therapeutic efficacy in CHC patients. We therefore investigated the impact of DAA on FM symptoms in CHC patients. Methods We enrolled consecutive CHC patients who received DAA. FM symptoms were evaluated based on the 2016 American College of Rheumatology (ACR) fibromyalgia scale at baseline and 12 and 24 weeks after cessation of DAA therapy. Logistic regression was performed to determine the influence of HCV on FM at baseline. We also recruited individuals who underwent a health checkup examination as the control group, and calculated the standardized prevalence ratio of FM in CHC patients. Comparisons of fibromyalgia in different time points were undertaken using the Wilcoxon signed-rank test. Results A total of 33 CHC patients (15 males and 18 females) and 402 controls were recruited. All CHC patients achieved sustained virological response. Two (6%) patients and two (0.5%) controls fulfilled the diagnostic criteria for FM, and the standardized prevalence ratio was 23.9 in CHC patients. Logistic regression also showed increased odds for FM in CHC patients after adjusting for age and sex (OR: 14.4; 95%CI: 1.6, 128.0). In addition, their fibromyalgianess scale decreased at 12 and 24 weeks after DAA therapy. In conclusion, CHC patients were more likely to develop FM. Implementation of DAA therapy might improve FM symptoms in these patients.

Gentle Touch Therapy, Pain Relief and Neuroplasticity at Baseline in Fibromyalgia Syndrome: A Randomized, Multicenter Trial with Six-Month Follow-Up

Background: Fibromyalgia (FM) is considered a stress-related disorder characterized mainly by chronic widespread pain. Its pathogenesis is unknown, but cumulative evidence points at dysfunctional transmitter systems and inflammatory biomarkers that may underlie the major symptoms of the condition. This study aimed to evaluate pain scores (primary outcome), quality of life, inflammatory biomarkers and neurotransmitter systems in women with FM (secondary outcomes) subjected to gentle touch therapy (GTT) or placebo. Methods: A total of 64 female patients with FM were randomly assigned to two groups, namely GTT (n = 32) or Placebo (n = 32). Clinical assessments were conducted at baseline and post-intervention with six-month follow-up. We measured serum catecholamines (dopamine), indolamines and intermediary metabolites (serotonin or 5-hydroxyindolacetic acid (5-HIAA)), as well as tetrahydrobiopterin (BH4), which is a cofactor for the synthesis of neurotransmitters and inflammatory biomarkers in women with FM. A group of healthy individuals with no intervention (control group) was used to compare biochemical measurements. Intervention effects were analyzed using repeated measures (RM) two-way ANOVA followed by Bonferroni post hoc test and mixed ANCOVA model with intention to treat. Results: Compared to placebo, the GTT group presented lower pain scores and brain-derived neurotrophic factor (BDNF) levels without altering the quality of life of women with FM. Changes in BDNF had a mediating role in pain. Higher baseline serum BDNF and 5-HIAA or those with a history of anxiety disorder showed a higher reduction in pain scores across time. However, women with higher serum dopamine levels at baseline showed a lower effect of the intervention across the observation period revealed by an ANCOVA mixed model. Conclusions: In conclusion, lower pain scores were observed in the GTT group compared to the placebo group without altering the quality of life in women with FM. Reductions in BDNF levels could be a mechanism of FM pain status improvement. In this sense, the present study encourages the use of these GTT techniques as an integrative and complementary treatment of FM.

Research in Mindfulness Interventions for Patients With Fibromyalgia: A Critical Review

Fibromyalgia is one of the most common causes of widespread chronic pain. It has a huge impact on the quality of life, namely because it appears earlier in life than most of the chronic pain conditions. Furthermore, emotional-cognitive distress factors, such as depression and anxiety, are a common feature in patients with fibromyalgia. The neurobiological mechanisms underlying fibromyalgia remain mostly unknown. Among non-pharmacological treatments, cognitive-behavioral therapy has been used during the last decade, namely with the enrolment of patients in programs of mindfulness-based stress reduction (MBSR) and in mindfulness-based interventions (MBI). We critically analyzed the literature to search for scientific evidence for the use of MBI in fibromyalgia. The studies were evaluated as to several outcomes of fibromyalgia improvement along with aspects of the study design which are currently considered relevant for research in mindfulness. We conclude that despite the sparsity of well-structured longitudinal studies, there are some promising results showing that the MBI are effective in reducing the negative aspects of the disease. Future design of studies using MBI in fibromyalgia management should be critically discussed. The importance of active controls, evaluation of sustained effects along with investigation of the subserving neurobiological mechanisms and detailed reports of possible adverse effects should be considered.

Thalamocortical bistable switch as a theoretical model of fibromyalgia pathogenesis inferred from a literature survey

Fibromyalgia (FM) is an unsolved central pain processing disturbance. We aim to provide a unifying model for FM pathogenesis based on a loop network involving thalamocortical regions, i.e., the ventroposterior lateral thalamus (VPL), the somatosensory cortex (SC), and the thalamic reticular nucleus (TRN). The dynamics of the loop have been described by three differential equations having neuron mean firing rates as variables and containing Hill functions to model mutual interactions among the loop elements. A computational analysis conducted with MATLAB has shown a transition from monostability to bistability of the loop behavior for a weakening of GABAergic transmission between TRN and VPL. This involves the appearance of a high-firing-rate steady state, which becomes dominant and is assumed to represent pathogenic pain processing giving rise to chronic pain. Our model is consistent with a bulk of literature evidence, such as neuroimaging and pharmacological data collected on FM patients, and with correlations between FM and immunoendocrine conditions, such as stress, perimenopause, chronic inflammation, obesity, and chronic dizziness. The model suggests that critical targets for FM treatment are to be found among immunoendocrine pathways leading to GABA/glutamate imbalance having an impact on the thalamocortical system.

Role of Etanercept and Infliximab on Nociceptive Changes Induced by the Experimental Model of Fibromyalgia

Background: Fibromyalgia is a clinical condition that affects 1% to 5% of the population. No proper therapy has been currently found. It has been described that inflammation plays a central role in the nerve sensitizations that characterize the pathology. Methods: This paper aimed to evaluate the efficacy of etanercept and infliximab in the management of pain sensitization. Fibromyalgia was induced by three injections once a day of reserpine at the dose of 1 mg/kg. Etanercept (3 mg/kg) and infliximab (10 mg/kg) were administered the day after the last reserpine injection and then 5 days after that. Behavioral analyses were conducted once a week, and molecular investigations were performed at the end of the experiment. Results: Our data confirmed the major effect of infliximab administration as compared to etanercept: infliximab administration strongly reduced pain sensitization in thermal hyperalgesia and mechanical allodynia. From the molecular point of view, infliximab reduced the activation of microglia and astrocytes and the expression of the purinergic P2X7 receptor ubiquitously expressed on glia and neurons. Downstream of the P2X7 receptor, infliximab also reduced p38-MAPK overexpression induced by the reserpine administration. Conclusion: Etanercept and infliximab treatment caused a significant reduction in pain. In particular, rats that received infliximab showed less pain sensitization. Moreover, infliximab reduced the activation of microglia and astrocytes, reducing the expression of the purinergic receptor P2X7 and p38-MAPK pathway.

Effect of ancient Khorasan wheat on gut microbiota, inflammation, and short-chain fatty acid production in patients with fibromyalgia

BACKGROUND

Fibromyalgia (FM) syndrome is mainly characterized by widespread pain, sleeping disorders, fatigue, and cognitive dysfunction. In many cases, gastrointestinal distress is also reported, suggesting the potential pathogenic role of the gut microbiota (GM). The GM is deeply influenced by several environmental factors, especially the diet, and recent findings highlighted significant symptom improvement in FM patients following various nutritional interventions such as vegetarian diet, low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols based diets, gluten-free diet, and especially an ancient grain supplementation. In particular, a recent study reported that a replacement diet with ancient Khorasan wheat led to an overall improvement in symptom severity of FM patients.

AIM

To examine the effects of ancient Khorasan wheat on the GM, inflammation, and short-chain fatty acid production in FM patients.

METHODS

After a 2-wk run-in period, 20 FM patients were enrolled in this randomized, double-blind crossover trial. In detail, they were assigned to consume either Khorasan or control wheat products for 8 wk and then, following an 8-wk washout period, crossed. Before and after treatments, GM characterization was performed by 16S rRNA sequencing while the fecal molecular inflammatory response and the short-chain fatty acids (SCFAs) were respectively determined with the Luminex MAGPIX detection system and a mass chromatography-mass spectrometry method.

RESULTS

The Khorasan wheat replacement diet, in comparison with the control wheat diet, had more positive effects on intestinal microbiota composition and on both the fecal immune and SCFAs profiles such as the significant increase of butyric acid levels (P = 0.054), candidatus Saccharibacteria (P = 9.95e-06) and Actinobacteria, and the reduction of Enterococcaceae (P = 4.97e-04). Moreover, the improvement of various FM symptoms along with the variation of some gut bacteria after the Khorasan wheat diet have been documented; in fact we reported positive correlations between Actinobacteria and both Tiredness Symptoms Scale (P < 0.001) and Functional Outcome of Sleep Questionnaire (P < 0.05) scores, between Verrucomicrobiae and both Widespread Pain Index (WPI) + Symptom Severity scale (SS) (P < 0.05) and WPI (P < 0.05) scores, between candidatus Saccharibacteria and SS score (P < 0.05), and between Bacteroidales and Sleep-Related and Safety Behaviour Questionnaire score (P < 0.05).

CONCLUSION

The replacement diet based on ancient Khorasan wheat results in beneficial GM compositional and functional modifications that positively correlate with an improvement of FM symptomatology.

Distinct CholinomiR Blood Cell Signature as a Potential Modulator of the Cholinergic System in Women with Fibromyalgia Syndrome

Fibromyalgia syndrome (FMS) is a heterogeneous chronic pain syndrome characterized by musculoskeletal pain and other key co-morbidities including fatigue and a depressed mood. FMS involves altered functioning of the central and peripheral nervous system (CNS, PNS) and immune system, but the specific molecular pathophysiology remains unclear. Anti-cholinergic treatment is effective in FMS patient subgroups, and cholinergic signaling is a strong modulator of CNS and PNS immune processes. Therefore, we used whole blood small RNA-sequencing of female FMS patients and healthy controls to profile microRNA regulators of cholinergic transcripts (CholinomiRs). We compared microRNA profiles with those from Parkinson’s disease (PD) patients with pain as disease controls. We validated the sequencing results with quantitative real-time PCR (qRT-PCR) and identified cholinergic targets. Further, we measured serum cholinesterase activity in FMS patients and healthy controls. Small RNA-sequencing revealed FMS-specific changes in 19 CholinomiRs compared to healthy controls and PD patients. qRT-PCR validated miR-182-5p upregulation, distinguishing FMS patients from healthy controls. mRNA targets of CholinomiRs bone morphogenic protein receptor 2 and interleukin 6 signal transducer were downregulated. Serum acetylcholinesterase levels and cholinesterase activity in FMS patients were unchanged. Our findings identified an FMS-specific CholinomiR signature in whole blood, modulating immune-related gene expression.

COVID-19 associated hospitalization in 571 patients with fibromyalgia-A population-based study

OBJECTIVE

To identify predicators of patients with fibromyalgia (FM) that are associated with a severe COVID-19 disease course.

METHODS

We utilized the data base of the Clalit Health Services (CHS); the largest public organization in Israel, and extracted data concerning patients with FM. We matched two subjects without FM to each subject with FM by sex and age and geographic location. Baseline characteristics were evaluated by t-test for continuous variables and chi-square for categorical variables. Predictors of COVID-19 associated hospitalization were identified using univariable logistic regression model, significant variables were selected and analyzed by a multivariable logistic regression model.

RESULTS

The initial cohort comprised 18,598 patients with FM and 36,985 matched controls. The mean age was 57.5± 14.5(SD), with a female dominance of 91%. Out of this cohort we extracted the study population, which included all patients contracted with COVID-19, and consisted of 571 patients with FM and 1008 controls. By multivariable analysis, the following variables were found to predict COVID-19 associated hospitalization in patients with FM: older age (OR, 1.25; CI, 1.13-1.39; p<0.001), male sex (OR, 2.63; CI, 1.18-5.88; p<0.05) and hypertension (OR, 1.75; CI, 1.04-2.95; p<0.05).

CONCLUSION

The current population-based study revealed that FM per se was not directly associated with COVID-19 hospitalization or related mortality. Yet classical risk factors endangering the general population were also relevant among patients with FM.

The Role of Nutrient Supplementation in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

The multifaceted clinical presentation of fibromyalgia (FM) supports the modern understanding of the disorder as a more global condition than one simply affecting pain sensation. The main pharmacologic therapies used clinically include anti-epileptics and anti-depressants. Conservative treatment options include exercise, myofascial release, psychotherapy, and nutrient supplementation.

METHODS

Narrative review.

RESULTS

Nutrient supplementation is a broadly investigated treatment modality as numerous deficiencies have been linked to FM. Additionally, a proposed link between gut microbiome patterns and chronic pain syndromes has led to studies investigating probiotics as a possible treatment. Despite positive results, much of the current evidence regarding this topic is of poor quality, with variable study designs, limited sample sizes, and lack of control groups.

CONCLUSIONS

The etiology of FM is complex, and has shown to be multi-factorial with genetics and environmental exposures lending influence into its development. Preliminary results are promising, however, much of the existing evidence regarding diet supplementation is of poor quality. Further, more robust studies are needed to fully elucidate the potential of this alternative therapeutic option.

The role of the vagus nerve in fibromyalgia syndrome

Fibromyalgia (FM) syndrome is a common illness characterized by chronic widespread pain, sleep problems, fatigue, and cognitive difficulties. Dysfunctional neurotransmitter systems that influence the body's endogenous stress response systems are thought to underlie many of the major FM-related symptoms. A model of FM pathogenesis suggests biological and psychosocial variables interact to influence the genetic predisposition, but the precise mechanisms remain unclear. The Polyvagal Theory provides a theoretical framework from which to investigate potential biological mechanisms. The vagus nerve (VN) has anti-inflammatory properties via its afferent and efferent fibers. A low vagal tone (as assessed by low heart rate variability), has been observed in painful and inflammatory diseases, including FM, while the ventral branch of the VN is linked to emotional expression and social engagement. These anti-inflammatory and psychological (limbic system) properties of the VN may possess therapeutic potential in treating FM. This review paper summarizes the scientific literature regarding the potential role of the VN in transducing and/or therapeutically managing FM signs and symptoms.

Extra-Articular Manifestations and Comorbidities in Psoriatic Disease: A Journey Into the Immunologic Crosstalk

Psoriatic arthritis (PsA) is a chronic inflammatory disease primarily affecting peripheral and axial joints, with the possible presence of extra-articular manifestations (EAMs), such as psoriasis, uveitis, and inflammatory bowel disease. Recently, the concept of psoriatic disease (PsD) has been proposed to define a systemic condition encompassing, in addition to joints and EAMs, some comorbidities (e.g., metabolic syndrome, type II diabetes, hypertension) that can affect the disease outcome and the achievement of remission. EAMs and comorbidities in PsA share common immunopathogenic pathways linked to the systemic inflammation of this disease; these involve a broad variety of immune cells and cytokines. Currently, various therapeutics are available targeting different cytokines and molecules implicated in the inflammatory response of this condition; however, despite an improvement in the management of PsA, comprehensive disease control is often not achievable. There is, therefore, a big gap to fill especially in terms of comorbidities and EAMs management. In this review, we summarize the clinical aspects of the main comorbidities and EAMs in PsA, and we focus on the immunopathologic features they share with the articular manifestations. Moreover, we discuss the effect of a diverse immunomodulation and the current unmet needs in PsD.

Fibromyalgia: a new facet of the post-COVID-19 syndrome spectrum? Results from a web-based survey

Objective

Postacute COVID-19 syndrome (PACS) is an emerging entity characterised by a large array of manifestations, including musculoskeletal complaints, fatigue and cognitive or sleep disturbances. Since similar symptoms are present also in patients with fibromyalgia (FM), we decided to perform a web-based cross-sectional survey aimed at investigating the prevalence and predictors of FM in patients who recovered from COVID-19.

Methods

Data were anonymously collected between 5 and 18 April 2021. The collection form consisted of 28 questions gathering demographic information, features and duration of acute COVID-19, comorbid diseases, and other individual’s attributes such as height and weight. The American College of Rheumatology (ACR) Survey Criteria and the Italian version of the Fibromyalgia Impact Questionnaire completed the survey.

Results

A final sample of 616 individuals (77.4% women) filled the form 6±3 months after the COVID-19 diagnosis. Of these, 189 (30.7%) satisfied the ACR survey criteria for FM (56.6% women). A multivariate logistic regression model including demographic and clinical factors showed that male gender (OR: 9.95, 95% CI 6.02 to 16.43, p<0.0001) and obesity (OR: 41.20, 95% CI 18.00 to 98.88, p<0.0001) were the strongest predictors of being classified as having post-COVID-19 FM. Hospital admission rate was significantly higher in men (15.8% vs 9.2%, p=0.001) and obese (19.2 vs 10.8%, p=0.016) respondents.

Conclusion

Our data suggest that clinical features of FM are common in patients who recovered from COVID-19 and that obesity and male gender affect the risk of developing post-COVID-19 FM.

MAO-A Inhibition by Metaxalone Reverts IL-1β-Induced Inflammatory Phenotype in Microglial Cells

Experimental and clinical studies have suggested that several neurological disorders are associated with the occurrence of central nervous system neuroinflammation. Metaxalone is an FDA-approved muscle relaxant that has been reported to inhibit monoamine oxidase A (MAO-A). The aim of this study was to investigate whether metaxalone might exert antioxidant and anti-inflammatory effects in HMC3 microglial cells. An inflammatory phenotype was induced in HMC3 microglial cells through stimulation with interleukin-1β (IL-1β). Control cells and IL-1β-stimulated cells were subsequently treated with metaxalone (10, 20, and 40 µM) for six hours. IL-1β stimulated the release of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), but reduced the anti-inflammatory cytokine interleukin-13 (IL-13). The upstream signal consisted of an increased priming of nuclear factor-kB (NF-kB), blunted peroxisome proliferator-activated receptor gamma (PPARγ), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression. IL-1β also augmented MAO-A expression/activity and malondialdehyde levels and decreased Nrf2 mRNA expression and protein levels. Metaxalone decreased MAO-A activity and expression, reduced NF-kB, TNF-α, and IL-6, enhanced IL-13, and also increased PPARγ, PGC-1α, and Nrf2 expression. The present experimental study suggests that metaxalone has potential for the treatment of several neurological disorders associated with neuroinflammation.

Co-Players in Chronic Pain: Neuroinflammation and the Tryptophan-Kynurenine Metabolic Pathway

Chronic pain is an unpleasant sensory and emotional experience that persists or recurs more than three months and may extend beyond the expected time of healing. Recently, nociplastic pain has been introduced as a descriptor of the mechanism of pain, which is due to the disturbance of neural processing without actual or potential tissue damage, appearing to replace a concept of psychogenic pain. An interdisciplinary task force of the International Association for the Study of Pain (IASP) compiled a systematic classification of clinical conditions associated with chronic pain, which was published in 2018 and will officially come into effect in 2022 in the 11th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11) by the World Health Organization. ICD-11 offers the option for recording the presence of psychological or social factors in chronic pain; however, cognitive, emotional, and social dimensions in the pathogenesis of chronic pain are missing. Earlier pain disorder was defined as a condition with chronic pain associated with psychological factors, but it was replaced with somatic symptom disorder with predominant pain in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) in 2013. Recently clinical nosology is trending toward highlighting neurological pathology of chronic pain, discounting psychological or social factors in the pathogenesis of pain. This review article discusses components of the pain pathway, the component-based mechanisms of pain, central and peripheral sensitization, roles of chronic inflammation, and the involvement of tryptophan-kynurenine pathway metabolites, exploring the participation of psychosocial and behavioral factors in central sensitization of diseases progressing into the development of chronic pain, comorbid diseases that commonly present a symptom of chronic pain, and psychiatric disorders that manifest chronic pain without obvious actual or potential tissue damage.

The Role of Vitamin D in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

Fibromyalgia (FM) is a complex disorder characterized primarily by chronic, widespread musculoskeletal pain. Currently, the Food and Drug Administration (FDA) has approved the use of three medications to treat FM: pregabalin, duloxetine, and milnacipran. The pharmaceutical intervention has lacked consistent pain relief among all patients. Therefore, the investigation into alternative treatment options has grown in interest. This narrative review aims to evaluate the evidence regarding vitamin D for the treatment of FM.

METHODS

Narrative review.

RESULTS

Low serum vitamin D has been linked to various chronic pain states. An association between vitamin D deficiency and FM has been reported but is controversial in the literature. Some studies have documented the beneficial effects of vitamin D supplementation on reducing pain symptoms and improving the overall quality of life in those with FM. Despite these positive findings, many of the studies regarding this topic lack adequate power to make substantial conclusions about the effects of vitamin D on FM.

CONCLUSION

Existing studies provide promising results. However, additional high-quality data on vitamin D supplementation is needed before recommendations for pain management can be made. Vitamin D supplementation is inexpensive, has minimal side effects, and can benefit FM patients regardless of its efficacy in pain control. Additionally, high-quality studies are warranted to fully elucidate the potential of vitamin D to manage chronic pain in FM.

Human Endogenous Retrovirus as Therapeutic Targets in Neurologic Disease

Human endogenous retroviruses (HERVs) are ancient retroviral DNA sequences established into germline. They contain regulatory elements and encoded proteins few of which may provide benefits to hosts when co-opted as cellular genes. Their tight regulation is mainly achieved by epigenetic mechanisms, which can be altered by environmental factors, e.g., viral infections, leading to HERV activation. The aberrant expression of HERVs associates with neurological diseases, such as multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS), inflammatory processes and neurodegeneration. This review summarizes the recent advances on the epigenetic mechanisms controlling HERV expression and the pathogenic effects triggered by HERV de-repression. This article ends by describing new, promising therapies, targeting HERV elements, one of which, temelimab, has completed phase II trials with encouraging results in treating MS. The information gathered here may turn helpful in the design of new strategies to unveil epigenetic failures behind HERV-triggered diseases, opening new possibilities for druggable targets and/or for extending the use of temelimab to treat other associated diseases.

IL-5 mediates monocyte phenotype and pain outcomes in fibromyalgia

ABSTRACT

Fibromyalgia (FM) is characterized by widespread chronic pain, fatigue, and somatic symptoms. The influence of phenotypic changes in monocytes on symptoms associated with FM is not fully understood. The primary aim of this study was to take a comprehensive whole-body to molecular approach in characterizing relationships between monocyte phenotype and FM symptoms in relevant clinical populations. Lipopolysaccharide-evoked and spontaneous secretion of IL-5 and other select cytokines from circulating monocytes was higher in women with FM compared to women without pain. In addition, greater secretion of IL-5 was significantly associated with pain and other clinically relevant psychological and somatic symptoms of FM. Furthermore, higher levels of pain and pain-related symptoms were associated with a lower percentage of intermediate monocytes (CD14++/CD16+) and a greater percentage of nonclassical monocytes (CD14+/CD16++) in women with FM. Based on findings from individuals with FM, we examined the role of IL-5, an atypical cytokine secreted from monocytes, in an animal model of widespread muscle pain. Results from the animal model show that IL-5 produces analgesia and polarizes monocytes toward an anti-inflammatory phenotype (CD206+). Taken together, our data suggest that monocyte phenotype and their cytokine profiles are associated with pain-related symptoms in individuals with FM. Furthermore, our data show that IL-5 has a potential role in analgesia in an animal model of FM. Thus, targeting anti-inflammatory cytokines such as IL-5 secreted by circulating leukocytes could serve as a promising intervention to control pain and other somatic symptoms associated with FM.

Green Light Exposure Improves Pain and Quality of Life in Fibromyalgia Patients: A Preliminary One-Way Crossover Clinical Trial

OBJECTIVE

Fibromyalgia is a functional pain disorder in which patients suffer from widespread pain and poor quality of life. Fibromyalgia pain and its impact on quality of life are not effectively managed with current therapeutics. Previously, in a preclinical rat study, we demonstrated that exposure to green light-emitting diodes (GLED) for 8 hours/day for 5 days resulted in antinociception and reversal of thermal and mechanical hypersensitivity associated with models of injury-related pain. Given the safety of GLED and the ease of its use, our objective is to administer GLED as a potential therapy to patients with fibromyalgia.

DESIGN

One-way crossover clinical trial.

SETTING

United States.

METHOD

We enrolled 21 adult patients with fibromyalgia recruited from the University of Arizona chronic pain clinic who were initially exposed to white light-emitting diodes and then were crossed over to GLED for 1 to 2 hours daily for 10 weeks. Data were collected by using paper surveys.

RESULTS

When patients were exposed to GLED, but not white light-emitting diodes, they reported a significant reduction in average pain intensity on the 10-point numeric pain scale. Secondary outcomes were assessed by using the EQ-5D-5L survey, Short-Form McGill Pain Questionnaire, and Fibromyalgia Impact Questionnaire and were also significantly improved in patients exposed to GLED. GLED therapy was not associated with any measured side effects in these patients.

CONCLUSION

Although the mechanism by which GLED elicits pain reduction is currently being studied, these results supporting its efficacy and safety merit a larger clinical trial.

Fear of pain moderates the relationship between self-reported fatigue and methionine allele of catechol-O-methyltransferase gene in patients with fibromyalgia

Previous research has shown a consistent association among genetic factors, psychological symptoms and pain associated with fibromyalgia. However, how these symptoms interact to moderate genetic factors in fibromyalgia has rarely been studied to date. The present research investigates whether psychological symptoms can moderate the effects of catechol-O-methyltransferase on pain and fatigue. A total of 108 women diagnosed with fibromyalgia and 77 healthy control participants took part in the study. Pain, fatigue, and psychological symptoms (anxiety, depression, pain catastrophizing, fear of pain and fear of movement) were measured by self-report questionnaires. Two types of statistical analyses were performed; the first was undertaken to explore the influences of COMT genotypes on clinical symptoms by comparing patients with fibromyalgia and healthy controls. In the second analysis, moderation analyses to explore the role of psychological symptoms as potential factors that moderate the relationship between pain/fatigue and COMT genotypes were performed. The main results indicated that patients carrying the Met/Met genotype reported significantly higher levels of fatigue than heterozygote carriers (i.e., Met/Val genotype) and higher levels of fatigue, but not significantly different, than Val homozygote carriers. Among patients with fibromyalgia carrying methionine alleles (i.e., Met/Met + Met/Val carriers), only those who scored high on medical fear of pain, experienced an intensified feeling of fatigue. Thus, the present research suggests that fear of pain, as a psychological symptom frequently described in fibromyalgia may act as a moderating factor in the relationship between the Met allele of the COMT gene and the increase or decrease in self-reported fatigue. Although further research with wider patient samples is needed to confirm the present findings, these results point out that the use of psychological interventions focused on affective symptomatology might be a useful tool to reduce the severity of fibromyalgia.

The dichotomous role of epiregulin in pain

It has recently been shown that epidermal growth factor receptor (EGFR) contributes to the pathogenesis of pain. We scanned genetic markers within genes coding for receptors of the EGFR family (EGFR, ERBB2, ERBB3, and ERBB4) and their ligands (AREG, BTC, EGF, EPGN, EREG, HBEGF, MUC4, NRG1, NRG2, NRG3, NRG4, and TGFA) for association with self-reported pain intensity in patients with chronic facial pain who participated in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) cohort. We found that only epiregulin (EREG) was associated with pain. The strongest effect was observed for a minor allele at rs6836436 in EREG, which was associated with lower chronic pain intensity. However, the same allele was associated with higher facial pain intensity among cases with recent onset of facial pain. Similar trends were observed in an independent cohort of UK Biobank (UKB) where the minor allele at rs6836436 was associated with a higher number of acute pain sites but a lower number of chronic pain sites. Expression quantitative trait loci analyses established rs6836436 as a loss-of-function variant of EREG. Finally, we investigated the functional role of EREG using mouse models of chronic and acute pain. Injecting mice with an EREG monoclonal antibody reversed established mechanosensitivity in the complete Freund's adjuvant and spared nerve injury models of chronic pain. However, the EREG monoclonal antibody prolonged allodynia when administered during the development of complete Freund's adjuvant-induced mechanosensitivity and enhanced pain behavior in the capsaicin model of acute pain.

Fibromyalgia and obesity: A comprehensive systematic review and meta-analysis

INTRODUCTION

Obesity has been associated with several complications, including musculoskeletal disorders. Aim of the present systematic review was to identify all available evidence on the relationship between fibromyalgia (FM) and obesity, including epidemiological association, impact of obesity on FM severity and effect of weight loss strategies on FM symptoms.

METHODS

MedLine, Cochrane Central Register of Controlled Trials and Web of Science databases were searched up to September 2020 to identify eligible articles. Data from studies reporting the prevalence of obesity in FM patients were pooled using a random-effects model.

RESULTS

After removal of duplicate records, 393 studies proceeded to review. A total of 41 articles were deemed eligible for inclusion in final synthesis. Quality assessment revealed that the overall risk of bias was high. The overall prevalence of obesity in FM was 35.7% (95% CI: 31.8 - 39.9%), with higher figures reported for USA. The majority of studies included demonstrated that obesity is associated with different domains of the disorder, including composite measures of activity, pain severity, tender point count, stiffness, fatigue, physical functioning/disability, sleep, cognitive dysfunction, and quality of life; the strength of correlation was weak on average. Inconsistent data were available regarding the correlation with depression and anxiety. Only few studies addressed the effect of therapeutic weight loss in FM, either by bariatric surgery, diet/exercise combination or behavioral weight loss, providing preliminary evidence for a potential benefit of weight loss in ameliorating FM symptoms.

CONCLUSIONS

Available data support a potential interplay between obesity and FM-related symptoms. Weight management should be encouraged in patients with FM.

Metabolomic analysis coupled with extreme phenotype sampling identified that lysophosphatidylcholines are associated with multisite musculoskeletal pain

ABSTRACT

Musculoskeletal pain often occurs simultaneously at multiple anatomical sites. The aim of the study was to identify metabolic biomarkers for multisite musculoskeletal pain (MSMP) by metabolomics with an extreme phenotype sampling strategy. The study participants (n = 610) were derived from the Newfoundland Osteoarthritis Study. Musculoskeletal pain was assessed using a self-reported pain questionnaire where painful sites were circled on a manikin by participants and the total number of painful sites were calculated. Targeted metabolomic profiling on fasting plasma samples was performed using the Biocrates AbsoluteIDQ p180 kit. Plasma cytokine concentrations including tumor necrosis factor-α, interleukin-6, interleukin-1β, and macrophage migration inhibitory factor were assessed by enzyme-linked immunosorbent assay. Data on blood cholesterol profiles were retrieved from participants' medical records. Demographic, anthropological, and clinical information was self-reported. The number of reported painful sites ranged between 0 and 21. Two hundred and five participants were included in the analysis comprising 83 who had ≥7 painful sites and 122 who had ≤1 painful site. Women and younger people were more likely to have MSMP (P ≤ 0.02). Multisite musculoskeletal pain was associated with a higher risk of having incontinence, worse functional status and longer period of pain, and higher levels of low-density lipoprotein and non-high-density lipoprotein cholesterol (all P ≤ 0.03). Among the 186 metabolites measured, 2 lysophosphatidylcholines, 1 with 26 carbons with no double bond and 1 with 28 carbons with 1 double bond, were significantly and positively associated with MSMP after adjusting for multiple testing with the Bonferroni method (P ≤ 0.0001) and could be considered as novel metabolic markers for MSMP.

Serial whole-body cryotherapy in fibromyalgia is effective and alters cytokine profiles

Introduction

Whole-body cryotherapy (WBC) has shown to be beneficial in the treatment of fibromyalgia (FM). There is cumulative evidence that cytokines play a crucial role in FM. It’s unknown whether clinical effects of WBC can be demonstrated at the molecular level and how long the effects last.

Methods

We compared effects of serial WBC (6 sessions (− 130 °C in 6 weeks) in FM patients and healthy controls (HC). Primary outcome was the change in pain level (visual analogue scale 0–100 mm) after 6 sessions. Secondary outcomes were a change in disease activity (revised Fibromyalgia Impact Questionnaire) and pain after 3 sessions and 3 months after discontinued therapy and in cytokine levels (interleukin (IL-)1, IL-6, tumor necrosis factor α (TNF-α) and IL-10). The patients’ opinions on the satisfaction, effectiveness and significance of WBC were evaluated.

Results

Twenty-three FM patients and 30 HC were enrolled. WBC resulted in a significant reduction in pain and disease activity after 3 and 6 sessions. No clinical benefit could be measured 3 months after discontinued treatment. Overall, probands were satisfied with WBC and considered WBC to be important and effective. FM patients had significantly different levels of IL-1, IL-6, TNF-α and IL-10 at each reading point compared to HC. Levels of IL-1, IL-6 and IL-10 were significantly altered over time in FM patients. Compared to HC FM patients showed a significantly different response of IL1, − 6 and − 10 to WBC.

Conclusion

Serial WBC is a fast acting and effective treatment for FM. Proven effects of WBC may be explained by changes in cytokines.

Application of Salivary Biomarkers in the Diagnosis of Fibromyalgia

Fibromyalgia (FM) is a highly prevalent syndrome that impairs the quality of life of the patients; however, its diagnosis is complex and mainly centered on pain symptoms. The study of salivary biomarkers has proven highly useful for the diagnosis and prognosis of numerous diseases. The objective of this review was to gather published data on the utilization of salivary biomarkers to facilitate and complement the diagnosis of FM. Salivary biomarkers used in FM diagnosis include cortisol; calgranulin; and the enzymes α-amylase, transaldolase, and phosphoglycerate mutase. Increased serum levels of C-reactive protein, cytokines interleukin 1-β, interleukin 6, interleukin 8, interleukin 10, interleukin 17, tumor necrosis factor α, and various chemokines may serve as salivary biomarkers, given observations of their increased serum levels in patients with FM. Further research is warranted to study in depth the role and performance of biomarkers currently used in FM diagnosis/prognosis and to identify novel salivary biomarkers for this disease.

Mindfulness-Based Program Plus Amygdala and Insula Retraining (MAIR) for the Treatment of Women with Fibromyalgia: A Pilot Randomized Controlled Trial

The lack of highly effective treatments for fibromyalgia (FM) represents a great challenge for public health. The objective of this parallel, pilot randomized controlled trial (RCT) was two-fold: (1) to analyze the clinical effects of mindfulness plus amygdala and insula retraining (MAIR) compared to a structurally equivalent active control group of relaxation therapy (RT) in the treatment of FM; and (2) to evaluate its impact on immune-inflammatory markers and brain-derived neurotrophic factor (BDNF) in serum. A total of 41 FM patients were randomized into two study arms: MAIR (intervention group) and RT (active control group), both as add-ons of treatment as usual. MAIR demonstrated significantly greater reductions in functional impairment, anxiety, and depression, as well as higher improvements in mindfulness, and self-compassion at post-treatment and follow-up, with moderate to large effect sizes. Significant decreases in pain catastrophizing and psychological inflexibility and improvements in clinical severity and health-related quality of life were found at follow-up, but not at post-treatment, showing large effect sizes. The number needed to treat was three based on the criteria of ≥50% Fibromyalgia Impact Questionnaire (FIQ) reduction post-treatment. Compared to RT, the MAIR showed significant decreases in BDNF. No effect of MAIR was observed in immune-inflammatory biomarkers (i.e., TNF-α, IL-6, IL-10, and hs-CRP). In conclusion, these results suggest that MAIR, as an adjuvant of treatment-as-usual (TAU), appears to be effective for the management of FM symptoms and for reducing BDNF levels in serum.

Acupuncture decreased the risk of stroke among patients with fibromyalgia in Taiwan: A nationwide matched cohort study

BACKGROUND

The aim of this study was to investigate the effectiveness of acupuncture in decreasing the risk of stroke in patients with fibromyalgia.

METHODS

We enrolled patients who was newly diagnosed as having fibromyalgia between 1 January, 2000 and 31 December, 2010 from the Taiwanese National Health Insurance Research Database. The claim data for both the acupuncture cohort and non-acupuncture cohort were assessed from the index date to 31 December, 2013. A Cox regression model adjusted for age, sex, comorbidities, and drugs use was used to compare the hazard ratios of the two cohorts. The cumulative incidence of stroke was estimated by using the Kaplan-Meier method.

RESULTS

After performing a propensity score matching with a 1:1 ratio, there were 65,487 patients in the acupuncture and non-acupuncture cohorts with similar distributions in the baseline characteristics. The cumulative incidence of stroke was significantly lower in the acupuncture cohort (log-rank test, p < 0.001). In the follow-up period, 4,216 patients in the acupuncture cohort (11.01 per 1000 person-years) and 6,849 patients in the non-acupuncture cohort (19.82 per 1000 person-years) suffered from stroke (adjusted HR 0.53, 95% CI 0.51-0.55). Acupuncture favorably affected the incidence of stroke regardless of the patient's age, sex, comorbidities, and conventional drug use.

CONCLUSIONS

Our study found that acupuncture might have a beneficial effect on reducing the risk of stroke in patients with fibromyalgia in Taiwan. Additional clinical and basic science studies are warranted.

Low-Dose Naltrexone for the Treatment of Fibromyalgia: Investigation of Dose–Response Relationships

Objective

This study explores dose–response relationships when treating fibromyalgia with low-dose naltrexone.

Design

A single-blinded clinical trial was carried out using the “up-and-down” method.

Subjects

Subjects included women with a diagnosis of fibromyalgia aged 18–60 years who had been referred to treatment at a public pain clinic at a Danish university hospital.

Methods

The test doses were in the range 0.75–6 mg, and the dosing interval was 0.75 mg. The method was sequential and allowed predicting the dose effective in 50% (ED50) and 95% (ED95) of the subjects when the dose had shifted direction 10 times, and six pairs of “up-and-down” data were available.

Results

A total of 27 subjects were included in the study; two subjects were withdrawn. After inclusion of 25 evaluable subjects, the dose estimates were calculated as 3.88 mg for ED50 and 5.40 mg for ED95. As a secondary outcome, the effects on 10 common fibromyalgia symptoms were evaluated. A high interindividual variation was observed both in the symptom presentation at baseline and in which symptoms were reduced by low-dose naltrexone.

Conclusions

This study is the first to explore dose–response relationships in the treatment of fibromyalgia with low-dose naltrexone. Future placebo-controlled randomized clinical trials are needed, and according to our findings, 4.5 mg, which has previously been used, seems to be a relevant test dose. We recommend that future studies include additional nonpain fibromyalgia symptoms as outcome measures.

Significant correlation between plasma proteome profile and pain intensity, sensitivity, and psychological distress in women with fibromyalgia

Fibromyalgia (FM) is a complex pain condition where the pathophysiological and molecular mechanisms are not fully elucidated. The primary aim of this study was to investigate the plasma proteome profile in women with FM compared to controls. The secondary aim was to investigate if plasma protein patterns correlate with the clinical variables pain intensity, sensitivity, and psychological distress. Clinical variables/background data were retrieved through questionnaires. Pressure pain thresholds (PPT) were assessed using an algometer. The plasma proteome profile of FM (n = 30) and controls (n = 32) was analyzed using two-dimensional gel electrophoresis and mass spectrometry. Quantified proteins were analyzed regarding group differences, and correlations to clinical parameters in FM, using multivariate statistics. Clear significant differences between FM and controls were found in proteins involved in inflammatory, metabolic, and immunity processes. Pain intensity, PPT, and psychological distress in FM had associations with specific plasma proteins involved in blood coagulation, metabolic, inflammation and immunity processes. This study further confirms that systemic differences in protein expression exist in women with FM compared to controls and that altered levels of specific plasma proteins are associated with different clinical parameters.

Peripheral immune aberrations in fibromyalgia: A systematic review, meta-analysis and meta-regression

The objective was to identify immune alterations in patients with fibromyalgia syndrome (FMS) compared to healthy controls (HC) using meta-analysis and meta-regression. Six electronic databases were searched for suitable original articles investigating immune biomarkers in FMS in comparison to HC. We extracted outcomes and variables of interest, such as mean and SD of peripheral blood immune biomarkers, age or sex. A random-effects model with restricted maximum-likelihood estimator was used to compute effect sizes (standardized mean difference and 95% CI, Hedges' g) and meta-analysis, group meta-analysis and meta-regressions were conducted. Forty-three papers were included in this systematic review, of which 29 were suitable for meta-analysis. Interleukin (IL)-6 (g = 0.36 (0.09-0.63); I² = 85.94; p = 0.01), IL-4 (g = 0.50 (0.03-0.98); I² = 81.87; p = 0.04), and IL-17A (g = 0.53 (0.00-1.06); I² = 87.15; p = 0.05), were significantly higher in FMS compared to HC while also combinations of cytokines into relevant phenotypes were significantly upregulated including M1 macrophage (g = 0.23 (0.03-0.43); I² = 77.62; p = 0.02), and immune-regulatory (g = 0.40 (0.09-0.72); I² = 84.81; p = 0.01) phenotypes. Heterogeneity levels were very high and subgroup and meta-regression analyses showed that many covariates explained part of the heterogeneity including medication washout, sex, time of blood sampling and exclusion of patients with major depressive disorder. In conclusion, FMS is accompanied by a disbalance between upregulated pro-inflammatory (M1 and Th-17) and immune-regulatory cytokines although effect sizes are small-to-moderate. Based on our results we provide specific methodological suggestions for future research, which should assess Th-1, Th-17, chemokines, and Th-2 phenotypes while controlling for possible confounding variables specified in this study.

Anti-inflammatory and anti-hyperalgesic effects of milnacipran in inflamed rats: involvement of myeloperoxidase activity, cytokines and oxidative/nitrosative stress

BACKGROUND

Many injuries cause pain and inflammation, which are one of the major challenges for physicians. In this study, the analgesic and the anti-inflammatory effects of milnacipran were investigated on carrageenan-induced nociception and inflammation in male rats.

METHODS

Pain and inflammation were induced by injection of λ-carrageenan (1% v/v) into the hind paw. Indomethacin (10 mg/kg: ip) or milnacipran (10, 20 and 40 mg/kg: ip) were administered 30 min before carrageenan. Analgesia and inflammation were measured by hot plate and plethysmometer. Finally, lipid peroxidation, tumor necrosis factor alpha (TNF-α), Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), myeloperoxidase (MPO) activity, nitric oxide (NO) and total antioxidant capacity (TAC) status evaluated in the hind paw tissue.

RESULTS

The results showed that carrageenan caused hyperalgesia and inflammation in the hind paw tissue. Milnacipran (20 and 40 mg/kg) significantly and dose-dependently attenuated (65 ± 3.2%; p ≤0.01 and 42 ± 6.2%; p ≤ 0.001, respectively) carrageenan-induced inflammation and significantly increased (p ≤ 0.001) nociception threshold. Also, milnacipran (20 and 40 mg/kg) significantly suppressed levels of malondialdehyde (MDA), NO (p ≤ 0.05), MPO activity, TNF-α, IL-1β and IL-6 (p ≤ 0.001) following carrageenan injection. Additionally, milnacipran (10, 20 and 40 mg/kg) significantly augmented (p ≤ 0.05) TAC status following carrageenan in the hind paw tissue.

CONCLUSION

In the present study, milnacipran showed anti-nociceptive and anti-inflammatory effects on carrageenan-induced hyperalgesia and inflammation in a dose-dependent manner. Milnacipran reduced inflammatory edema and increased the paw withdrawal threshold probably through suppression of MDA, NO, TNF-α, IL-1β, IL-6 and MPO activity, and increase of TAC status in the hind paw tissue. Therefore, milnacipran holds important potential as an anti-inflammatory and anti-nociceptive drug. Although, further clinical trials to confirm this issue, is required.