Fatigue: Biomedicine, Health & Behavior - Volume 6, Issue 2, 2018

Volume 6, Issue 2, 2018

• Task related cerebral blood flow changes of patients with chronic fatigue syndrome: an arterial spin labeling study
• Longitudinal associations of lymphocyte subsets with clinical outcomes in chronic fatigue syndrome

  Abstract - Background: Chronic fatigue syndrome (CFS) is characterized by prolonged fatigue and other physical and neurocognitive symptoms. Some studies suggest that CFS is accompanied by disruptions in the number and function of various lymphocytes. However, it is not clear which lymphocytes might influence CFS symptoms. Purpose: To determine if patient reported fatigue symptoms and physical functioning scores significantly changed across time with lymphocyte counts as evidence of a relation among chronic fatigue symptoms and the immune response. Methods: The current longitudinal, naturalistic study assessed the cellular expression of three lymphocyte subtypes – natural killer (NK) cells (CD3 − CD16+ and CD3 − CD56+) and naïve T cells (CD4 + CD45RA+) – to determine whether changes in lymphocytes at 4 time points across 18 months were associated with clinical outcomes, including CFS symptoms, physical functioning, and vitality, among patients with chronic fatigue. Latent growth curve models were used to examine the longitudinal relationship between lymphocytes and clinical outcomes. Results: Ninety-three patients with Fukuda-based CFS and seven with non-CFS fatigue provided study data. Results indicated that higher proportions of naïve T cells and lower proportions of NK cells were associated with worse physical functioning, whereas higher proportions of NK cells (CD3 − CD16+) and lower proportions of naïve T cells were associated with fewer CFS symptoms. Conclusion: These findings suggest that lymphocytes are modestly related to clinical outcomes over time.

• Patient perceptions of post exertional malaise (Abstract with full text upon request)
• The international collaborative on fatigue following infection (COFFI)

  Abstract - Background: The purpose of the Collaborative on Fatigue Following Infection (COFFI) is for investigators of post-infection fatigue (PIF) and other syndromes to collaborate on these enigmatic and poorly understood conditions by studying relatively homogeneous populations with known infectious triggers. Utilising COFFI, pooled data and stored biosamples will support both epidemiological and laboratory research to better understand the etiology and risk factors for development and progression of PIF. Methods: COFFI consists of prospective cohorts from the UK, Netherlands, Norway, USA, New Zealand and Australia, with some cohorts closed and some open to recruitment. The 9 cohorts closed to recruitment total over 3000 participants, including nearly 1000 with infectious mononucleosis (IM), > 500 with Q fever, > 800 with giardiasis, > 600 with campylobacter gastroenteritis (CG), 190 with Legionnaires disease and 60 with Ross River virus. Follow-ups have been at least 6 months and up to 10 years. All studies use the Fukuda criteria for defining chronic fatigue syndrome (CFS). Results: Preliminary analyses indicated that risk factors for non-recovery from PIF included lower physical fitness, female gender, severity of the acute sickness response, and autonomic dysfunction. Conclusions: COFFI (https://internationalcoffi.wordpress.com/) is an international collaboration which should be able to answer questions based on pooled data that are not answerable in the individual cohorts. Possible questions may include the following: Do different infections trigger different PIF syndromes (e.g. CFS vs. irritable bowel syndrome)?; What are longitudinal predictors of PIF and its severity?

T cell A type of white blood cell which is mostly produced or matured in the thymus gland (hence T-cell) and is involved in the adaptive immune response on a cellular level. Also known as a T lymphocyte. (Learn more: www.youtube.com)

etiology The cause of origin, especially of a disease.

post-exertional malaise (PEM) - A notable exacerbation of symptoms brought on by small physical or cognitive exertions. PEM may be referred to as a "crash" or "collapse" and can last for days or weeks. Symptoms can include cognitive impairments, muscle pain, trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, and others.