Tag: Marshall-Gradisnik

The adoption of chronic fatigue syndrome/myalgic encephalomyelitis case definitions to assess prevalence: a systematic review

Abstract:

PURPOSE: Prevalence estimates have been based on several case definitions of chronic fatigue syndrome (CFS). The purpose of this work is to provide a rigorous overview of their application in prevalence research.

METHODS: A systematic review of primary studies reporting the prevalence of CFS since 1990 was conducted. Studies were summarized according to study design, prevalence estimates, and case definition used to ascertain cases.

RESULTS: Thirty-one studies were retrieved, and eight different case definitions were found. Early estimates of CFS prevalence were based on the 1988 Centers for Disease Control and Prevention, Australian, and Oxford. The 1994 Centers for Disease Control and Prevention, however, has been adopted internationally, as a general standard. Only one study has reported prevalence according to the more recent, Canadian Consensus Criteria. Additional estimates were also found according to definitions by Ho-Yen, the 2005 Centers for Disease Control and Prevention empirical definition, and an epidemiological case definition.

CONCLUSIONS: Advances in clinical case definitions during the past 10 years such as the Canadian Consensus Criteria have received little attention in prevalence research. Future assessments of prevalence should consider adopting more recent developments, such as the newly available International Consensus Criteria. This move could improve the surveillance of more specific cases found within CFS.

Copyright © 2013 Elsevier Inc. All rights reserved.

 

Source: Johnston S, Brenu EW, Staines DR, Marshall-Gradisnik S. The adoption of chronic fatigue syndrome/myalgic encephalomyelitis case definitions to assess prevalence: a systematic review. Ann Epidemiol. 2013 Jun;23(6):371-6. doi: 10.1016/j.annepidem.2013.04.003. https://www.ncbi.nlm.nih.gov/pubmed/23683713

 

The prevalence of chronic fatigue syndrome/ myalgic encephalomyelitis: a meta-analysis

Abstract:

PURPOSE: To perform a meta-analysis to examine variability among prevalence estimates for CFS/ME, according to the method of assessment used.

METHODS: Databases were systematically searched for studies on CFS/ME prevalence in adults that applied the 1994 Centers for Disease Control (CDC) case definition.1 Estimates were categorized into two methods of assessment: self-reporting of symptoms versus clinical assessment of symptoms. Meta-analysis was performed to pool prevalences by assessment using random effects modeling. This was stratified by sample setting (community or primary care) and heterogeneity was examined using the I (2) statistic.

RESULTS: Of 216 records found, 14 studies were considered suitable for inclusion. The pooled prevalence for self-reporting assessment was 3.28% (95% CI: 2.24-4.33) and 0.76% (95% CI: 0.23-1.29) for clinical assessment. High variability was observed among self-reported estimates, while clinically assessed estimates showed greater consistency.

CONCLUSION: The observed heterogeneity in CFS/ME prevalence may be due to differences in method of assessment. Stakeholders should be cautious of prevalence determined by the self-reporting of symptoms alone. The 1994 CDC case definition appeared to be the most reliable clinical assessment tool available at the time of these studies. Improving clinical case definitions and their adoption internationally will enable better comparisons of findings and inform health systems about the true burden of CFS/ME.

 

Source: Johnston S, Brenu EW, Staines D, Marshall-Gradisnik S. The prevalence of chronic fatigue syndrome/ myalgic encephalomyelitis: a meta-analysis. Clin Epidemiol. 2013;5:105-10. doi: 10.2147/CLEP.S39876. Epub 2013 Mar 26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3616604/ (Full article)

 

Cytotoxic lymphocyte microRNAs as prospective biomarkers for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Abstract:

BACKGROUND: Immune dysfunction associated with a disease often has a molecular basis. A novel group of molecules known as microRNAs (miRNAs) have been associated with suppression of translational processes involved in cellular development and proliferation, protein secretion, apoptosis, immune function and inflammatory processes. MicroRNAs may be implicated in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME), where immune function is impaired. The objective of this study was to determine the association between miRNAs in cytotoxic cells and CFS/ME.

METHODS: Natural Killer (NK) and CD8(+)T cells were preferentially isolated from peripheral blood mononuclear cells from all participants (CFS/ME, n=28; mean age=41.8±9.6 years and controls, n=28; mean age=45.3±11.7 years), via negative cell enrichment. Following total RNA extraction and subsequent synthesis of cDNA, reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) was used to determine the expression levels of nineteen miRNAs.

RESULTS: There was a significant reduction in the expression levels of miR-21, in both the NK and CD8(+)T cells in the CFS/ME sufferers. Additionally, the expression of miR-17-5p, miR-10a, miR-103, miR-152, miR-146a, miR-106, miR-223 and miR-191 was significantly decreased in NK cells of CFS/ME patients in comparison to the non-fatigued controls.

LIMITATIONS: The results from these investigations are not yet transferable into the clinical setting, further validatory studies are now required.

CONCLUSIONS: Collectively these miRNAs have been associated with apoptosis, cell cycle, development and immune function. Changes in miRNAs in cytotoxic cells may reduce the functional capacity of these cells and disrupt effective cytotoxic activity along with other immune functions in CFS/ME patients.

Copyright © 2012 Elsevier B.V. All rights reserved.

 

Source: Brenu EW, Ashton KJ, van Driel M, Staines DR, Peterson D, Atkinson GM, Marshall-Gradisnik SM. Cytotoxic lymphocyte microRNAs as prospective biomarkers for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. J Affect Disord. 2012 Dec 10;141(2-3):261-9. doi: 10.1016/j.jad.2012.03.037. Epub 2012 May 8. https://www.ncbi.nlm.nih.gov/pubmed/22572093

 

Longitudinal investigation of natural killer cells and cytokines in chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

BACKGROUND: Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is an etiologically unexplained disorder characterised by irregularities in various aspects of the immunological function. Presently, it is unknown whether these immunological changes remain consistent over time. This study investigates Natural Killer (NK) cell cytotoxic activity, NK cell subsets (CD56brightCD16- and CD56dimCD16+) and cytokines, over the course of a12 month period in patients with CFS/ME.

METHODS: The participants in the study comprised 65 (47.2 ± 11.5 years) CFS/ME participants and 21 (45.2 ± 9.3 years) non-fatigued controls. Flow cytometry protocols were used to assess NK subsets and NK cytotoxic activity at various time points that included baseline (T1), 6 (T2) and 12 months (T3). Cytokine secretions were measured following mitogenic stimulation of peripheral blood mononuclear cells.

RESULTS: NK cytotoxic activity was significantly decreased in the CFS/ME patients at T1, T2 and T3 compared to the non-fatigued group. Additionally, in comparison to the non-fatigued controls, the CFS/ME group had significantly lower numbers of CD56brightCD16- NK cells at both T1 and T2. Interestingly, following mitogenic stimulation, cytokine secretion revealed significant increases in IL-10, IFN-γ and TNF-α at T1 in the CFS/ME group. A significant decrease was observed at T2 in the CFS/ME group for IL-10 and IL-17A while at T3, IL-2 was increased in the CFS/ME group in comparison to the non-fatigued controls. Overall cytotoxic activity was significantly decreased at T3 compared to T1 and T2. CD56brightCD16- NK cells were much lower at T2 compared to T1 and T3. IL-10 and IL-17A secretion was elevated at T2 in comparison to T1 and T3.

CONCLUSION: These results confirm decreases in immune function in CFS/ME patients, suggesting an increased susceptibility to viral and other infections. Furthermore, NK cytotoxic activity may be a suitable biomarker for diagnosing CFS/ME as it was consistently decreased during the course of the 12 months study.

 

Source: Brenu EW, van Driel ML, Staines DR, Ashton KJ, Hardcastle SL, Keane J, Tajouri L, Peterson D, Ramos SB, Marshall-Gradisnik SM. Longitudinal investigation of natural killer cells and cytokines in chronic fatigue syndrome/myalgic encephalomyelitis. J Transl Med. 2012 May 9;10:88. doi: 10.1186/1479-5876-10-88. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3464733/ (Full article)

 

Myalgic encephalomyelitis: International Consensus Criteria

Abstract:

The label ‘chronic fatigue syndrome’ (CFS) has persisted for many years because of the lack of knowledge of the aetiological agents and the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation and multisystemic neuropathology, it is more appropriate and correct to use the term ‘myalgic encephalomyelitis’ (ME) because it indicates an underlying pathophysiology. It is also consistent with the neurological classification of ME in the World Health Organization’s International Classification of Diseases (ICD G93.3).

Consequently, an International Consensus Panel consisting of clinicians, researchers, teaching faculty and an independent patient advocate was formed with the purpose of developing criteria based on current knowledge. Thirteen countries and a wide range of specialties were represented. Collectively, members have approximately 400 years of both clinical and teaching experience, authored hundreds of peer-reviewed publications, diagnosed or treated approximately 50 000 patients with ME, and several members coauthored previous criteria. The expertise and experience of the panel members as well as PubMed and other medical sources were utilized in a progression of suggestions/drafts/reviews/revisions.

The authors, free of any sponsoring organization, achieved 100% consensus through a Delphi-type process. The scope of this paper is limited to criteria of ME and their application. Accordingly, the criteria reflect the complex symptomatology. Operational notes enhance clarity and specificity by providing guidance in the expression and interpretation of symptoms. Clinical and research application guidelines promote optimal recognition of ME by primary physicians and other healthcare providers, improve the consistency of diagnoses in adult and paediatric patients internationally and facilitate clearer identification of patients for research studies.

© 2011 The Association for the Publication of the Journal of Internal Medicine.

Comment in: A controversial consensus–comment on article by Broderick et al. [J Intern Med. 2012]

 

Source: Carruthers BM, van de Sande MI, De Meirleir KL, Klimas NG, Broderick G, Mitchell T, Staines D, Powles AC, Speight N, Vallings R, Bateman L, Baumgarten-Austrheim B, Bell DS, Carlo-Stella N, Chia J, Darragh A, Jo D, Lewis D, Light AR, Marshall-Gradisbik S, Mena I, Mikovits JA, Miwa K, Murovska M, Pall ML, Stevens S. Myalgic encephalomyelitis: International Consensus Criteria. J Intern Med. 2011 Oct;270(4):327-38. doi: 10.1111/j.1365-2796.2011.02428.x. Epub 2011 Aug 22. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427890/ (Full article)

 

Immunological abnormalities as potential biomarkers in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Abstract:

BACKGROUND: Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is characterised by severe prolonged fatigue, and decreases in cognition and other physiological functions, resulting in severe loss of quality of life, difficult clinical management and high costs to the health care system. To date there is no proven pathomechanism to satisfactorily explain this disorder. Studies have identified abnormalities in immune function but these data are inconsistent. We investigated the profile of markers of immune function (including novel markers) in CFS/ME patients.

METHODS: We included 95 CFS/ME patients and 50 healthy controls. All participants were assessed on natural killer (NK) and CD8(+) T cell cytotoxic activities, Th1 and Th2 cytokine profile of CD4(+) T cells, expression of vasoactive intestinal peptide receptor 2 (VPACR2), levels of NK phenotypes (CD56(bright) and CD56(dim)) and regulatory T cells expressing FoxP3 transcription factor.

RESULTS: Compared to healthy individuals, CFS/ME patients displayed significant increases in IL-10, IFN-γ, TNF-α, CD4(+)CD25(+) T cells, FoxP3 and VPACR2 expression. Cytotoxic activity of NK and CD8(+) T cells and NK phenotypes, in particular the CD56(bright) NK cells were significantly decreased in CFS/ME patients. Additionally granzyme A and granzyme K expression were reduced while expression levels of perforin were significantly increased in the CFS/ME population relative to the control population. These data suggest significant dysregulation of the immune system in CFS/ME patients.

CONCLUSIONS: Our study found immunological abnormalities which may serve as biomarkers in CFS/ME patients with potential for an application as a diagnostic tool.

 

Source: Brenu EW, van Driel ML, Staines DR, Ashton KJ, Ramos SB, Keane J, Klimas NG, Marshall-Gradisnik SM. Immunological abnormalities as potential biomarkers in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. J Transl Med. 2011 May 28;9:81. doi: 10.1186/1479-5876-9-81. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3120691/ (Full article)

 

Immune and hemorheological changes in chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) is a multifactorial disorder that affects various physiological systems including immune and neurological systems. The immune system has been substantially examined in CFS with equivocal results, however, little is known about the role of neutrophils and natural killer (NK) phenotypes in the pathomechanism of this disorder. Additionally the role of erythrocyte rheological characteristics in CFS has not been fully expounded. The objective of this present study was to determine deficiencies in lymphocyte function and erythrocyte rheology in CFS patients.

METHODS: Flow cytometric measurements were performed for neutrophil function, lymphocyte numbers, NK phenotypes (CD56(dim)CD16(+) and CD56(bright)CD16(-)) and NK cytotoxic activity. Erythrocyte aggregation, deformability and fibrinogen levels were also assessed.

RESULTS: CFS patients (n = 10) had significant decreases in neutrophil respiratory burst, NK cytotoxic activity and CD56(bright)CD16(-) NK phenotypes in comparison to healthy controls (n = 10). However, hemorheological characteristic, aggregation, deformability, fibrinogen, lymphocyte numbers and CD56(dim)CD16(+) NK cells were similar between the two groups.

CONCLUSION: These results indicate immune dysfunction as potential contributors to the mechanism of CFS, as indicated by decreases in neutrophil respiratory burst, NK cell activity and NK phenotypes. Thus, immune cell function and phenotypes may be important diagnostic markers for CFS. The absence of rheological changes may indicate no abnormalities in erythrocytes of CFS patients.

 

Source: Brenu EW, Staines DR, Baskurt OK, Ashton KJ, Ramos SB, Christy RM, Marshall-Gradisnik SM. Immune and hemorheological changes in chronic fatigue syndrome. J Transl Med. 2010 Jan 11;8:1. doi: 10.1186/1479-5876-8-1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829521/ (Full article)