E. Brenu

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

BackgroundChronic 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.MethodsWe 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 (CD56bright and CD56dim) and regulatory T cells expressing FoxP3 transcription factor.ResultsCompared 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 CD56bright 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.ConclusionsOur study found immunological abnormalities which may serve as biomarkers in CFS/ME patients with potential for an application as a diagnostic tool.

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

BackgroundChronic 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.MethodsThe participants in the study comprised 65 (47.2u2009±u200911.5u2009years) CFS/ME participants and 21 (45.2 ±9.3u2009years) 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 12u2009months (T3). Cytokine secretions were measured following mitogenic stimulation of peripheral blood mononuclear cells.ResultsNK 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.ConclusionThese 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 12u2009months study.

Immune and hemorheological changes in Chronic Fatigue Syndrome

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.

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

BACKGROUNDnImmune 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.nnnMETHODSnNatural 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.nnnRESULTSnThere 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.nnnLIMITATIONSnThe results from these investigations are not yet transferable into the clinical setting, further validatory studies are now required.nnnCONCLUSIONSnCollectively 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.

Anabolic androgenic steroids effects on the immune system: a review

Androgenic anabolic steroids (AAS) are synthetic derivatives of the male hormone testosterone. AAS are used by athletes and recreational users of all ages to enhance their athletic performance and/or physical appearance. While several adverse effects of AAS abuse have been described, their effect on the immune system has not been clearly elucidated. The literature generally indicates that supraphysiologic doses of AAS with an intact steroid nucleus are immunosuppressive, that is they reduce immune cell number and function. While those with alterations to the steroid nucleus are immunostimulatory as they induce the proliferation of T cells and other immune cells. Specifically, several common AAS have been shown to adversely influence lymphocyte differentiation and proliferation, antibody production, Natural Killer Cytotoxic activity and the production of certain cytokines, thereby altering the immune reaction. These effects may be profound and long lasting depending on the dosing regime, types or combinations of AAS used and the extent and duration of AAS abuse. Nevertheless, the effects of long term use of supraphysiologic doses of AAS on the immune system remain uncertain.

Assessment of immune function after short-term administration of recombinant human growth hormone in healthy young males

Growth hormone (GH) is a commonly used drug aimed at improving sport performance. The aim of this study is to evaluate the immunomodulatory effects of short-term administration of recombinant GH (rhGH) in healthy young males. NK cell number, activity and phenotype, T cell number, CD4+ (Th1/Th2) cytokine production of IL2, IL4, IL6, IL10, TNF-α and IFN-γ and CD4+/CD8+ ratio with particular attention to the possible correlation to IGF-I production were investigated. 30 males (27xa0±xa09xa0years) were randomly assigned to placebo (nxa0=xa015) or drug (rhGH) 1xa0mg/day groups (nxa0=xa015) with daily injection for 7xa0days. IGF-I plasma concentration and flow cytometry data were generated at baseline and days 8, 15, 22 and 29 post injection. Data analysis used General Linear Model with repeated measures, Bonferroni correction factor and significance at pxa0≤xa00.05. Serum IGF-I levels (ng/mL) increased significantly (pxa0≤xa00.01) on day 8 (0.48xa0±xa00.78) after injections compared to baseline (0.31xa0±xa00.07) and days 15 (0.33xa0±xa00.06), 22 (0.29xa0±xa00.05) and 29 (0.29xa0±xa00.06). A significant time effect was noted in IL10 secretion (pg/mL) from day 15 (Pxa0=xa035.14xa0±xa019.93, rhGHxa0=xa026.63xa0±xa016.39) to days 22 (Pxa0=xa061.32xa0±xa020.41, rhGHxa0=xa074.99xa0±xa046.91) and 29 (Pxa0=xa0101.98xa0±xa067.25, rhGHxa0=xa0107.74;xa0±xa0122.58). There was no correlation between IGF-I and NK activity, phenotype or number along with T lymphocyte number, CD4+/CD8+ ratio or Th1 and Th2 cytokine production. In conclusion, cytokine secretion spectrum was not affected by short-term rhGH administration in young males.

Assessment of the hemorheological profile of koala and echidna

Koala, a marsupial, and echidna, a monotreme, are mammals native to Australia. Blood viscosity (62.5-1250s(-1)), red blood cell (RBC) deformability, RBC aggregation, aggregability and surface charge, and hematological parameters were measured in blood samples from six koalas and six echidnas and compared to adult human blood. Koala had the largest RBC mean cell volume (107.7+/-2.6fl) compared to echidna (81.3+/-2.6fl) and humans (88.4+/-1.2fl). Echidna blood exhibited the highest viscosity over the entire range of shear rates. Echidna RBC were significantly less deformable than koala RBC but more deformable than human RBC. Echidna RBC had significantly lower aggregability (i.e., aggregation in standardized dextran medium) than koala or human RBC, while aggregation in autologous plasma was similar for the three species. Erythrocyte surface charge as indexed by RBC electrophoretic mobility was similar for human and echidna cells but was 40% lower for koala RBC. Data obtained during this preliminary study indicate that koala and echidna have distinct hemorheological characteristics; investigation of these properties may reveal patterns relevant to specific behavioral and physiological features of these animals.

Gene Expression in Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS) is a disorder of unknown origin likely affecting multiple physiological processes. CFS is often a diagnosis of exclusion following a history of 6 months or more where patients may experience partial to full recovery, relapse or a worsening in symptoms and hence deterioration in health (Brkic et al., 2011). The clinical manifestations include moderate to severe fatigue, muscle pain, swollen lymph nodes, headaches, impaired sleep and cognition (Fukuda et al., 1994). A diagnosis of CFS is made using questionnaires which include Centre for Disease Prevention and control criteria for CFS, the Australian, British and Canadian CFS classifications and the recently developed World Health Organisation’s International Classification of Diseases for CFS (Carruthers et al., 2011, Carruthers et al., 2003; Fukuda et al., 1994; Lloyd et al., 1990; Sharpe et al., 1991). CFS is a heterogeneous and multifactorial disorder. Mechanisms to explain the underlying factors and processes that are responsible for disease progression and symptom profile of this disorder remains to be established. However, research has demonstrated that CFS impacts the endocrine, neurological, immune and metabolic processes resulting in impaired physiological homeostasis (Brenu et al., 2010; Demitrack, 1997; Schwartz et al., 1994). While these processes are likely compromised and collectively contribute to ill health in CFS patients, CFS remains a disorder lacking a clear molecular or biochemical cause.

Haemorheology of the eastern grey kangaroo and the Tasmanian devil

The blood of two Australian marsupials, the eastern grey kangaroo (Macropus giganteus) and the Tasmanian devil (Sarcophilus harrisii), has been reported to have greater oxygen-carrying capacity (i.e. haemoglobin content) when compared with that of placental mammals. We investigated whether alterations of blood rheological properties are associated with the increased oxygen-carrying capacity of these marsupials. Eastern grey kangaroos (nu2009=u20096) and Tasmanian devils (nu2009=u20094) were anaesthetised for blood sampling; human blood (nu2009=u20096) was also sampled for comparison. Laboratory measurements included blood and plasma viscosity, red blood cell (RBC) deformability, RBC aggregation and the intrinsic tendency of RBC to aggregate, RBC surface charge and haematological parameters. Scanning electron micrographs of RBC from each species provided morphological information. High-shear blood viscosity at native haematocrit was highest for the Tasmanian devil. When haematocrit was adjusted to 0.4u2009Lu2009L–1, lower-shear blood viscosity was highest for the eastern grey kangaroo. RBC deformability was greatly reduced for the Tasmanian devil. Eastern grey kangaroo blood had the highest RBC aggregation, whereas Tasmanian devil RBC did not aggregate. The surface charge of RBC for marsupials was ~15% lower than that of humans. The dependence of oxygen-delivery effectiveness on haemoglobin concentration (i.e. oxygen content) and blood viscosity was quantitated by calculating the haematocrit to blood viscosity ratio and was 15–25% lower for marsupials compared with humans. Our results suggest that environmental pressures since the marsupial–monotreme divergence have influenced the development of vastly different strategies to maintain a match between oxygen demand and delivery.

Killer Cell Immunoglobulin-like Receptor Genotype and Haplotype Investigation of Natural Killer Cells from an Australian Population of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients.

Killer cell immunoglobulin-like receptor (KIR) genes encode for activating and inhibitory surface receptors, which are correlated with the regulation of Natural Killer (NK) cell cytotoxic activity. Reduced NK cell cytotoxic activity has been consistently reported in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients, and KIR haplotypes and allelic polymorphism remain to be investigated. The aim of this article was to conduct a pilot study to examine KIR genotypes, haplotypes, and allelic polymorphism in CFS/ME patients and nonfatigued controls (NFCs). Comparison of KIR and allelic polymorphism frequencies revealed no significant differences between 20 CFS/ME patients and 20 NFCs. A lower frequency of the telomeric A/B motif (P < 0.05) was observed in CFS/ME patients compared with NFCs. This pilot study is the first to report the differences in the frequency of KIR on the telomeric A/B motif in CFS/ME patients. Further studies with a larger CFS/ME cohort are required to validate these results.