Tag: Japan

Prevalence of Chronic Fatigue Syndrome (CFS) in Korea and Japan: A Meta-Analysis

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term disabling illness accompanied by fatigue unsolved by rest. However, ME/CFS is a poorly understood illness that lacks a universally accepted pathophysiology and treatment. A lack of CFS-related studies have been conducted in Asian countries. This study aimed to estimate and compare the prevalence of ME/CFS in Korea and Japan and conducted a meta-analysis.

Methods: We searched PubMed, EMBASE, Cochrane, and KMBASE for population-based prevalence studies of the two countries and synthesized the data according to the Fukuda case definition.

Results: Of the eight studies (five in Korea, three in Japan) included, the total prevalence rate of Korean studies was 0.77% (95% CI 0.34-1.76), and 0.76% (95% CI 0.46-1.25) for the Japanese studies. The prevalence rate in females was approximately two-fold higher than males in Korean studies (1.31% female vs. 0.60% male), while the gender difference was less obvious in Japanese studies (0.76% female vs. 0.65% male).

Conclusions: Further epidemiology studies on the female ME/CFS prevalence rate between countries may be required.

Source: Lim EJ, Son CG. Prevalence of Chronic Fatigue Syndrome (CFS) in Korea and Japan: A Meta-Analysis. J Clin Med. 2021 Jul 21;10(15):3204. doi: 10.3390/jcm10153204. PMID: 34361987. https://pubmed.ncbi.nlm.nih.gov/34361987/

Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and debilitating disease with no molecular diagnostics and no treatment options. To identify potential markers of this illness, we profiled 48 patients and 52 controls for standard laboratory tests, plasma metabolomics, blood immuno-phenotyping and transcriptomics, and fecal microbiome analysis. Here, we identified a set of 26 potential molecular markers that distinguished ME/CFS patients from healthy controls. Monocyte number, microbiome abundance, and lipoprotein profiles appeared to be the most informative markers.

When we correlated these molecular changes to sleep and cognitive measurements of fatigue, we found that lipoprotein and microbiome profiles most closely correlated with sleep disruption while a different set of markers correlated with a cognitive parameter. Sleep, lipoprotein, and microbiome changes occur early during the course of illness suggesting that these markers can be examined in a larger cohort for potential biomarker application. Our study points to a cluster of sleep-related molecular changes as a prominent feature of ME/CFS in our Japanese cohort.

Source: Kitami T, Fukuda S, Kato T, Yamaguti K, Nakatomi Y, Yamano E, Kataoka Y, Mizuno K, Tsuboi Y, Kogo Y, Suzuki H, Itoh M, Morioka MS, Kawaji H, Koseki H, Kikuchi J, Hayashizaki Y, Ohno H, Kuratsune H, Watanabe Y. Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population. Sci Rep. 2020 Nov 16;10(1):19933. doi: 10.1038/s41598-020-77105-y. PMID: 33199820; PMCID: PMC7669873.  https://www.nature.com/articles/s41598-020-77105-y (Full text)

Neurologic Abnormalities in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Review

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is an illness characterized by fatigue lasting for at least six months, post-exertional malaise, unrefreshing sleep, cognitive impairment and orthostatic intolerance. ME/CFS has been a controversial illness because it is defined exclusively by subjective complaints. However, recent studies of neuroimaging as well as analysis of blood markers, energy metabolism and mitochondrial function have revealed many objective biological abnormalities. Specifically, it is suspected that the symptoms of ME/CFS may be triggered by immune activation – either inside or outside the brain – through release of inflammatory cytokines. In this review, we summarize potentially important recent findings on ME/CFS, focusing on objective evidence.

Source: Komaroff AL, Takahashi R, Yamamura T, Sawamura M. Neurologic Abnormalities in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Review. Brain Nerve. 2018 Jan;70(1):41-54. doi: 10.11477/mf.1416200948. [Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/29348374

Immunopathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

A recent study on the pathogenesis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has revealed an elevation of inflammatory and anti-inflammatory cytokines in the sera and cerebrospinal fluids of the patients and presence of autoantibodies in subgroups of ME/CFS patients. Furthermore, investigator-initiated clinical trials have proved the efficacy of anti-CD20 antibody (rituximab), that eliminate B cells, in the treatment of ME/CFS. Based on these findings, we hypothesize that immune abnormalities, such as enhanced autoimmune responses, may play an essential role in the neuroinflammatory pathogenesis of ME/CFS.

Source: Yamamura T, Ono H, Sato W. Immunopathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Brain Nerve. 2018 Jan;70(1):35-40. doi: 10.11477/mf.1416200947 [Article in Japanese]   https://www.ncbi.nlm.nih.gov/pubmed/29348373

New Diagnostic Biomarkers for Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a persistent and unexplained pathological state characterized by exertional and severely debilitating fatigue, with/without symptoms of infection or neuropsychiatric symptoms, and with a minimum duration of 6 consecutive months. The pathogenesis of CFS is not fully understood. There are no firmly established diagnostic biomarkers or treatment, due to incomplete understanding of the etiology of CFS and diagnostic uncertainty. We performed comprehensive metabolomic analyses of blood samples obtained from patients with CFS and healthy controls to establish an objective diagnosis of CFS. Here, we review previous findings concerning the immune, endocrine, and metabolic system in animal models for CFS and the patients, and present our results which may contribute to the development of a diagnostic biomarker for CFS.

Source: Yamano E, Kataoka Y. New Diagnostic Biomarkers for Chronic Fatigue Syndrome. Brain Nerve. 2018 Jan;70(1):27-34. doi: 10.11477/mf.1416200946. [Article in Japanese]  https://www.ncbi.nlm.nih.gov/pubmed/29348372

Diagnosis and Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

We present here the Japanese clinical diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) that were proposed in 2016 by the Japanese Ministry of Health, Labour and Welfare study group. The clinical diagnosis criteria of ME/CFS were created to be used by healthcare agencies in charge of primary care practice. We also explain the current prognosis in ME/CFS and medical treatments used in major medical institutions in Japan.

Source: Kuratsune H. Diagnosis and Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Brain Nerve. 2018 Jan;70(1):11-18. doi: 10.11477/mf.1416200944.[Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/29348370

History of Researches on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disease characterized by chronic, profound, disabling, and unexplained fatigue. The first patient with ME/CFS in Japan was identified and described in 1990 by Prof. Teruo Kitani and Dr. Hirohiko Kuratsune of the Research Institute for Microbial Diseases, Osaka University. Since then, a variety of studies have been performed to determine the objective biomarkers of the disease. Although it is hypothesized that brain inflammation is involved in the pathophysiology of ME/CFS, there is to date no direct evidence of neuroinflammation in patients with ME/CFS. Our recent positron emission tomography study successfully demonstrated that microglial activation, which is linked to neuroinflammation, occurs in widespread brain areas in patients with ME/CFS, and is associated with the severity of the neuropsychological symptoms. Thus, evaluation of neuroinflammation in patients with ME/CFS may be essential for understanding the core pathophysiology of the disease, and for developing objective diagnostic criteria and effective medical treatments for ME/CFS. Here, we describe disease-related pathophysiological findings and topics, and discuss the history of the diagnostic and therapeutic attempts based on previous findings in Japan.

Source: Watanabe Y, Kuratsune H. History of Researches on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Brain Nerve. 2018 Jan;70(1):5-9. doi: 10.11477/mf.1416200943. [Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/29348369

Fibromyalgia and chronic fatigue syndrome in children

Abstract:

BACKGROUND: Fibromyalgia (FM) is characterized by widespread persistent pain and the presence of multiple discrete tender points. Chronic fatigue syndrome (CFS) is a syndrome characterized by debilitating fatigue associated with a variable number of non-specific complaints. Because neither condition had necessarily been recognized in children until recently, those patients have been treated as having school refusal without being diagnosed as having either syndrome. There is a considerable overlap of clinical symptoms between these two syndromes. It is therefore controversial as to whether these syndromes have the same pathogenesis or not. The aim of the present study was to clarify the relationship between these syndromes in children.

METHODS: Fifteen patients with FM and 21 patients with CFS were investigated both clinically and immunologically. Immunological assessments included thorough analysis of autoantibodies using several techniques.

RESULTS: Anti-nuclear antibody titers were higher and the prevalence of anti-Sa antibody was far more frequent in CFS patients than in FM patients.

CONCLUSION: CFS and FM are different from each other at least in childhood, from an immunological aspect, although some patients could have both conditions.

© 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

 

Source: Itoh Y, Shigemori T, Igarashi T, Fukunaga Y. Fibromyalgia and chronic fatigue syndrome in children. Pediatr Int. 2012 Apr;54(2):266-71. doi: 10.1111/j.1442-200X.2011.03514.x. Epub 2012 Jan 12. https://www.ncbi.nlm.nih.gov/pubmed/22115414

 

No association of xenotropic murine leukemia virus-related virus with prostate cancer or chronic fatigue syndrome in Japan

Abstract:

BACKGROUND: The involvement of xenotropic murine leukemia virus-related virus (XMRV) in prostate cancer (PC) and chronic fatigue syndrome (CFS) is disputed as its reported prevalence ranges from 0% to 25% in PC cases and from 0% to more than 80% in CFS cases. To evaluate the risk of XMRV infection during blood transfusion in Japan, we screened three populations–healthy donors (n = 500), patients with PC (n = 67), and patients with CFS (n = 100)–for antibodies against XMRV proteins in freshly collected blood samples. We also examined blood samples of viral antibody-positive patients with PC and all (both antibody-positive and antibody-negative) patients with CFS for XMRV DNA.

RESULTS: Antibody screening by immunoblot analysis showed that a fraction of the cases (1.6-3.0%) possessed anti-Gag antibodies regardless of their gender or disease condition. Most of these antibodies were highly specific to XMRV Gag capsid protein, but none of the individuals in the three tested populations retained strong antibody responses to multiple XMRV proteins. In the viral antibody-positive PC patients, we occasionally detected XMRV genes in plasma and peripheral blood mononuclear cells but failed to isolate an infectious or full-length XMRV. Further, all CFS patients tested negative for XMRV DNA in peripheral blood mononuclear cells.

CONCLUSION: Our data show no solid evidence of XMRV infection in any of the three populations tested, implying that there is no association between the onset of PC or CFS and XMRV infection in Japan. However, the lack of adequate human specimens as a positive control in Ab screening and the limited sample size do not allow us to draw a firm conclusion.

 

Source: Furuta RA, Miyazawa T, Sugiyama T, Kuratsune H, Ikeda Y, Sato E, Misawa N, Nakatomi Y, Sakuma R, Yasui K, Yamaguti K, Hirayama F. No association of xenotropic murine leukemia virus-related virus with prostate cancer or chronic fatigue syndrome in Japan. Retrovirology. 2011 Mar 17;8:20. doi: 10.1186/1742-4690-8-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065418/ (Full article)

 

Characteristics of chronic fatigue syndrome in a Japanese community population : chronic fatigue syndrome in Japan

Abstract:

This study seeks to estimate the prevalence of chronic fatigue syndrome (CFS) and assess the characteristics of CFS in a community population in Japan using laboratory tests and questionnaires for lifestyle, fatigue states, and depression states. The design of this study is a cross-sectional observational study. The setting of this study is a medical health checkup program in a general hospital.

This study was conducted with 1,430 Japanese (867 men and 563 women), 20 to 78 years of age. We classified participants who complained of fatigue according to the case definition of CFS proposed by the Centers for Disease Control and Prevention in the USA in 1994. Alcohol, caffeine, catechin and total polyphenol consumption, smoking status, sleep duration, and physical activity were evaluated using questionnaires.

The prevalence of CFS was 1.0% (95% CI 0.5-1.6%) of a community population in Japan. Although various lifestyle factors of the participants with CFS were similar to those without chronic fatigue, average sleep duration was significantly shorter among the participants with CFS (5.5 ± 0.8 h) compared to those without chronic fatigue (6.3 ± 0.9 h, P < 0.001). Proportion at subjects having average sleep duration of less than 6 h was 64.3% among the participants with CFS in contrast to only 15.0% in those without chronic fatigue (P < 0.001).

Among the eight case-defining symptoms, “Unrefreshing sleep” had high sensitivity and high specificity for screening CFS in Japanese population (92.9% and 87.8%, respectively). The average sleep duration was notably shorter in Japanese suffering from CFS. Further longitudinal study is needed to evaluate the possibility of extreme short sleep duration as a major cause of CFS in Japan.

 

Source: Hamaguchi M, Kawahito Y, Takeda N, Kato T, Kojima T. Characteristics of chronic fatigue syndrome in a Japanese community population : chronic fatigue syndrome in Japan. Clin Rheumatol. 2011 Jul;30(7):895-906. doi: 10.1007/s10067-011-1702-9. Epub 2011 Feb 8. https://www.ncbi.nlm.nih.gov/pubmed/21302125