Immune and hemorheological changes in Chronic Fatigue Syndrome

Abstract

BackgroundChronic 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.MethodsFlow cytometric measurements were performed for neutrophil function, lymphocyte numbers, NK phenotypes (CD56dimCD16+ and CD56brightCD16-) and NK cytotoxic activity. Erythrocyte aggregation, deformability and fibrinogen levels were also assessed.ResultsCFS patients (n = 10) had significant decreases in neutrophil respiratory burst, NK cytotoxic activity and CD56brightCD16- NK phenotypes in comparison to healthy controls (n = 10). However, hemorheological characteristic, aggregation, deformability, fibrinogen, lymphocyte numbers and CD56dimCD16+ NK cells were similar between the two groups.ConclusionThese 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.

Immune Abnormalities in Patients Meeting New Diagnostic Criteria for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

“…NK cell activity is a promising candidate for CFS/ME diagnostic marker. A global impairment in NK activity has consistently been observed in CFS/ME patients [7,15,16,19,20]. This suggests an inability of the NK cells in CFS/ME patients to clear viral and other microbial infections and also a prevalence of recurring viral infections.…”

“…Neutrophil dysfunction has received limited investigation is CFS/ME. Ultimately, perceived decreases in neutrophil respiratory burst and differential expression in HNA antigens highlight substantial deficits in the neutrophil function [15,32].…”

“…The activity of NK cells was measured using a well-known flow cytometeric method [14][15][16]. Briefly, isolated PBMCs (1×10 6 cells/ml) were stained with 0.4% PKH-26 fluorescent cell linker dye (SigmaAldrich, St Louis, MO).…”

“…Cells were stained with annexin V and 7-AAD (Becton Dickinson (BD) Pharmingen, San Diego, CA) and analysed on the BD FACS Calibur flow cytometer. Percent lysis was calculated for each sample at the different ratios as described previously [14][15][16].…”

Chronic Immune Response Hypothesis for Chronic Fatigue Syndrome: Experimental Results and Literature Overview

“…Among immune disfunctions the decrease either in number or functional activity of natural killer (NK) cells, especially in the number or activation status of CD56+ cells was found by many groups [Brenu EW et al, 2011;Fletcher MA, et al, 2010;Brenu EW et al, 2010;Mihaylova I. et al, 2007;Maher KJ et al, 2005, Nas K, 2011. Lorusso L. at al [2009] reported an increased number of CD8+ cytotoxic T lymphocytes; CD38 and HLA-DR activation markers and a decrease in CD11b expression associated with an increased expression of CD28+ T subsets.…”