Chronic fatigue syndrome and the immune system: "findings in search of meanings"

Polyunsaturated fatty acids levels and initial presentation of somatic symptoms induced by interferon-alpha therapy in patients with chronic hepatitis C viral infection

OBJECTIVES

Somatic symptoms are common in depressive disorder and are similar to sickness behaviors due to inflammatory activation after cytokine administration. Omega-3 polyunsaturated fatty acids (PUFAs) are natural anti-inflammatory agents and may reduce inflammation-induced behavioral changes. The aim of this study was to investigate the role of PUFAs on the development of somatic symptoms and depression in patients of hepatitis C virus infection (HCV) receiving interferon-alpha therapy (IFN-α) in a prospective manner.

METHODS

In this 24-week, prospective cohort study, 43 patients with chronic HCV ongoing IFN-α therapy were assessed with the mini-international neuropsychiatric interview for major depressive episodes and neurotoxicity rating scale (NRS) for somatic symptoms.

RESULTS

One-third later developed IFN-α-induced depression (depression (DEP) group). As compared to subjects without depression, DEP group had higher NRS scores (P < 0.001), lower eicosapentaenoic acid (EPA) levels (P = 0.038) at week 2. Somatic symptoms, regardless of painful/non-painful characteristics, had positive association with arachidonic acid (P < 0.05), and negative association with EPA (P < 0.05).

CONCLUSION

This study implies that early intervention with omega-3 PUFAs might be a promising strategy to prevent depression and somatic symptoms in patients receiving cytokine therapy.

Detection of Urine Metabolites in a Rat Model of Chronic Fatigue Syndrome before and after Exercise

Purpose. The aim of the present study was to elucidate the metabolic mechanisms associated with chronic fatigue syndrome (CFS) via an analysis of urine metabolites prior to and following exercise in a rat model. Methods. A rat model of CFS was established using restraint-stress, forced exercise, and crowded and noisy environments over a period of 4 weeks. Behavioral experiments were conducted in order to evaluate the model. Urine metabolites were analyzed via gas chromatography-mass spectrometry (GC-MS) in combination with multivariate statistical analysis before and after exercise. Results. A total of 20 metabolites were detected in CFS rats before and after exercise. Three metabolic pathways (TCA cycle; alanine, aspartate, and glutamate metabolism; steroid hormone biosynthesis) were significantly impacted before and after exercise, while sphingolipid metabolism alone exhibited significant alterations after exercise only. Conclusion. In addition to metabolic disturbances involving some energy substances, alterations in steroid hormone biosynthesis and sphingolipid metabolism were detected in CFS rats. Sphingosine and 21-hydroxypregnenolone may be key biomarkers of CFS, potentially offering evidence in support of immune dysfunction and hypothalamic-pituitary-adrenal (HPA) axis hypoactivity in patients with CFS.

Evaluation of the anti-fatigue effects of a traditional herbal drug, Gongjin-dan, under insufficient sleep conditions: study protocol for a randomised controlled trial

Background

Many herbal medicines are traditionally used as anti-fatigue agents in east Asian countries; however, there is a dearth of clinical evidence supporting the anti-fatigue effects of such medicines and their mechanisms. This study is a feasibility trial to assess the clinical efficacy of Gongjin-dan (GJD) and verify its mechanisms by exploring fatigue outcomes, including endocrine and immunological biomarkers in humans.

Methods/Design

To investigate the anti-fatigue effects of GJD and the mechanism underlying these effects, a randomised, double-blind, placebo-controlled crossover clinical trial was designed. Participants (24 healthy male volunteers) will be hospitalised for 4 days (3 nights), during which acute fatigue and stress conditions will be induced by sleep deprivation, and GJD or a placebo will be administered (twice daily). The primary outcome will be changes in serum cortisol levels, measured in the morning, as an objective biomarker of sleep deprivation-induced fatigue and stress. The secondary outcomes will include: the Fatigue Severity Scale; the Brief Fatigue Inventory, and the Leeds Sleep Evaluation Questionnaire scores; levels of salivary cortisol, epinephrine, norepinephrine, oxidative stress-related biomarkers, homocysteine, and immunological factors; and heart rate variability. After a washout period of more than 4 weeks, a second treatment phase will commence in which participants who were previously administered the placebo will receive the drug and vice versa, following the same treatment regime as in the first phase.

Discussion

This study protocol provides a unique opportunity to enhance our understanding of fatigue and the effects of GJD on fatigue in terms of endocrine and immunological mechanisms by validating the study design and determining feasibility. Findings from this trial will help researchers to design a pilot or definitive clinical trial of traditional herbal medicine for chronic fatigue.

Trial registration

Korean National Clinical Trial Registry CRIS; KCT0001681, registered on 29 October 2015.

Childhood stressors in the development of fatigue syndromes: a review of the past 20 years of research

BACKGROUND

Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are both highly prevalent conditions associated with extreme disability and with the development of co-morbid psychiatric disorders, such as depression and anxiety. Childhood stressors have been shown to induce persistent changes in the function of biological systems potentially relevant to the pathogenesis of both CFS and FM, such as the inflammatory system and the hypothalamic-pituitary-adrenal (HPA) axis. In this review, we examined whether multiple forms of childhood stressors are contributing factors to the development of these disorders, and of the associated psychiatric symptoms.

METHOD

Using PubMed, we identified 31 papers relevant to this narrative review. We included cohort studies and case-control studies, without any exclusion in terms of age and gender. No study characteristics or publication date restrictions were imposed.

RESULTS

Most studies across the literature consistently show that there is a strong association between experiences of childhood stressors and the presence of CFS and FM, with rates of CFS/FM being two- to three-fold higher in exposed than in unexposed subjects. We also found evidence for an increased risk for the development of additional symptoms, such as depression, anxiety and pain, in individuals with CFS and FM with a previous history of childhood stressors, compared with individuals with CFS/FM and no such history.

CONCLUSIONS

Our review confirms that exposure to childhood stressors is associated with the subsequent development of fatigue syndromes such as CFS and FM, and related symptoms. Further studies are needed to identify the mechanisms underlying these associations.

A Chinese herbal decoction, Danggui Buxue Tang, improves chronic fatigue syndrome induced by food restriction and forced swimming in rats

Danggui Buxue Tang (DBT), a Chinese medicinal decoction that contains Radix Angelicae sinensis (Danggui) and Radix Astragali (Huangqi) at a ratio of 1:5, is used commonly for treating women's ailments. The present study explored the effects of this preparation on chronic fatigue syndrome (CFS). Rats were subjected to a combination of food restriction and forced swimming to induce CFS, and rats were gavaged once daily with either 12 or 24 g/kg DBT for 28 days. Body weights, T-cell subset counts, (3) H-TdR incorporation measurements and mRNA levels of IL-1β, TNF-α, NF-кB, p38MAPK and JNK were determined on days 14 and 28. The swimming endurance capacity was measured on day 28. Rats that received DBT exhibited increased body weight and endurance capacity, corrected T cell subsets counts, increased (3) H-TdR incorporation and decreased mRNA levels of IL-1β, TNF-α, NF-кB, p38MAPK and JNK compared with rats that did not receive DBT. The results indicate that DBT can ameliorate CFS through immune modulation and may act to normalize cytokines and their related signaling pathways.

Effects of exercise on behavior and peripheral blood lymphocyte apoptosis in a rat model of chronic fatigue syndrome

This study examined the effects of exercise on behavior and peripheral blood leukocyte apoptosis in a rat model of chronic fatigue syndrome (CFS). Thirty-six healthy male Sprague-Dawley rats were equally randomized into 3 groups: the control group, CFS model group and the exercise group in terms of body weight. A total of 25 rats entered the final statistical analysis due to 11 deaths during the study. CFS model was established by subjecting the rats in CFS model group and exercise group to electric shock, chronic restraint stress and cold water swim. Besides, rats in the exercise group took running wheel exercise. After a week of conditioning feeding, model construction and running wheel exercise were performed simultaneously, and lasted for 23 consecutive days. The behavior experiments, including running wheel exercise, open-field test, tail suspension test and Morris water maze test, were conducted, either before or after the model establishment. Rats were sacrificed and peripheral blood was obtained for the assessment of lymphocyte apoptosis index by flow cytometry (FCM). It was found that as compared with those in the control group, the weight of the rats was decreased obviously (P<0.01), the mobility time in the open-field and the tail suspension tests was shortened significantly (P<0.01), the time to locate the platform was enhanced (P<0.01) and the cell apoptosis index was increased substantially (P<0.01) in the CSF model group. Meanwhile, in comparison to the model group, the behavior in the open-field and the tail suspension tests was improved significantly (P<0.05), and the apoptosis index decreased remarkably (P<0.01) in the exercise group. It is concluded that sport intervention can prevent lymphocyte apoptosis and improve animal behavior rather than the memory.