The potential role of ocular and otolaryngological mucus proteins in myalgic encephalomyelitis/chronic fatigue syndrome.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating illness associated with a constellation of other symptoms. While the most common symptom is unrelenting fatigue, many individuals also report suffering from rhinitis, dry eyes and a sore throat. Mucin proteins are responsible for contributing to the formation of mucosal membranes throughout the body. These mucosal pathways contribute to the body's defense mechanisms involving pathogenic onset. When compromised by pathogens the epithelium releases numerous cytokines and enters a prolonged state of inflammation to eradicate any particular infection. Based on genetic analysis, and computational theory and modeling we hypothesize that mucin protein dysfunction may contribute to ME/CFS symptoms due to the inability to form adequate mucosal layers throughout the body, especially in the ocular and otolaryngological pathways leading to low grade chronic inflammation and the exacerbation of symptoms.

Evaluation of natural killer cell assay performance on shipped blood specimens.

Documenting the importance of NK cell function as a biomarker for diseases and physiologic conditions including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), will require assays amenable to clinical implementation and standardization. Research studies typically perform NK functional assays on the day of sample collection. This pilot study was conducted to compare assay formats and specimen processing to identify those that are most tolerant of conditions required for shipping and amenable to standardization as shown by inter-assay and inter-laboratory correlation of results. We compared performance within and between assays that measure NK cell function using direct cytotoxicity [chromium-51 release (CRCA) or fluorescence (Flow Cytometry Cytotoxicity Assay, FCCA)] or an indirect surrogate marker (CD107a surface expression)]. Additional variables for within/between assay comparisons included time of testing (same day as specimen collection or next day within 24 h), specimen types [whole blood or isolated peripheral blood mononuclear cells (PBMCs)], and processing method (fresh or cryopreserved). Statistical measures included number of samples tested in assay conditions (n), medians (x͂), interquartile range (IQR), Pearson correlation coefficient (R2), and correlation p-value (p). Samples came from 3 clinics and included 31 participants. Same day testing was only available for the subset of participants enrolled from the site of the laboratory performing CRCA. Results from same day CRCA testing of whole blood were considered the gold standard [n = 10, x͂=10.0%, IQR = 7.2%], and correlated well with PBMCs isolated next day [n = 26, x͂= 15.6%, IQR = 13.1%] [R2 = 0.59, p = 0.03]. Next day CRCA results were compromised using whole blood or frozen PBMCs. Next day FCCA cytotoxicity in PBMC [n = 30, x͂=34.1%, IQR = 15.5%] correlated with same day CRCA PMBC [R2 = 0.8, p = 0.001] and next day CRCA PMBC [R2 = 0.5, p < 0.0001]. CD107a expression after induction by PMA and ionomycin did not correlate with other cytotoxicity measures. NK function can be measured in PBMCs isolated after overnight shipping/storage at ambient temperature and CRCA and FCCA results on this sample type are well correlated.

Post-exertional malaise is associated with greater symptom burden and psychological distress in patients diagnosed with Chronic Fatigue Syndrome.

OBJECTIVE: Post-exertional malaise (PEM) is often considered a cardinal symptom of Chronic Fatigue Syndrome (CFS). There is no gold standard diagnostic method for CFS, however, and the Centers for Disease Control (CDC) Fukuda case definition does not require PEM. Research has identified differences in symptom burden between patients according to PEM, but whether it is associated with psychological distress has not been investigated. METHODS: The CDC CFS Inventory, Fatigue Symptom Inventory, Profile of Mood States, Center for Epidemiologic Studies Depression Scale, Perceived Stress Scale, and subscales of the Sickness Impact Profile were administered to 261 patients diagnosed with the Fukuda criteria. PEM status (loPEM/hiPEM) was determined via self-reported post-exertional fatigue severity. Analyses of covariance (ANCOVA), controlling for age and gender, assessed cross-sectional group differences, and cross-sectional linear regressions using the continuous PEM severity predictor paralleled these analyses. RESULTS: hiPEM patients reported greater symptom intensity, frequency, and interference than loPEM counterparts (p's < .001). hiPEM patients also reported greater social disruption, depressive symptoms, and mood disturbance (p's ≤ .011). Groups did not differ in recent negative life experiences, perceived stress, or demographic variables. The results of regression analyses mirrored those of ANCOVAs. CONCLUSION: This study replicates the association between PEM and symptom burden and additionally associates PEM with psychological distress; psychological distress could, however, be a consequence of symptom burden. Differences between hiPEM and loPEM CFS patients highlight the heterogeneity of diagnoses resulting from the Fukuda criteria. It is also possible that PEM identifies particularly distressed patients for whom psychological intervention would be most beneficial.

Relationship satisfaction, communication self-efficacy, and chronic fatigue syndrome-related fatigue.

RATIONALE: Relationship dissatisfaction has been linked with worse health outcomes in many patient populations, though the mechanism(s) underlying this effect are unclear. Among patients with chronic fatigue syndrome (CFS) and their partners, there is evidence for a bi-directional association between poorer relationship satisfaction and the severity of CFS-related fatigue. OBJECTIVE: Here, we hypothesized that relationship dissatisfaction negatively impacts fatigue severity through greater depression and less patient satisfaction about communication about symptoms to partners. METHOD: Baseline data were drawn from diagnosed CFS patients (N = 150) participating in a trial testing the efficacy of a stress management intervention. Data derived from fatigue severity (Fatigue Symptom Index, FSI), depression (Center for Epidemiologic Survey-Depression, CES-D), relationship quality (Dyadic Adjustment Scale, DAS) and communication satisfaction (Patient Symptom Disclosure Satisfaction, PSDS) questionnaires were used for bootstrapped indirect effect analyses using parallel mediation structural equation modeling in Mplus (v8). Age and BMI were entered as covariates. RESULTS: Greater relationship satisfaction predicted greater communication satisfaction (p < 0.01) and lower CES-D scores (p < 0.01), which in turn were each significantly related to greater fatigue severity (p < 0.05). Tests of the indirect paths indicated that relationship satisfaction had a significant effect on fatigue severity through both constructs, but primarily via depression. There was no direct association between relationship satisfaction and fatigue severity after the intermediate variables (depression, communication satisfaction) were included in the model. CONCLUSION: Results highlight the importance of considering depression and communication-related factors when examining the effects of relationship satisfaction on CFS symptoms such as fatigue. Further mechanism-based, longitudinal research might identify relationship-related mediating variables that can be targeted therapeutically.

Leveraging Prior Knowledge of Endocrine Immune Regulation in the Therapeutically Relevant Phenotyping of Women With Chronic Fatigue Syndrome.

PURPOSE: The complex and varied presentation of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has made it difficult to diagnose, study, and treat. Its symptoms and likely etiology involve multiple components of endocrine and immune regulation, including the hypothalamic-pituitary-adrenal axis, the hypothalamic-pituitary-gonadal axis, and their interactive oversight of immune function. We propose that the persistence of ME/CFS may involve changes in the regulatory interactions across these physiological axes. We also propose that the robustness of this new pathogenic equilibrium may at least in part explain the limited success of conventional single-target therapies. METHODS: A comprehensive model was constructed of female endocrine-immune signaling consisting of 28 markers linked by 214 documented regulatory interactions. This detailed model was then constrained to adhere to experimental measurements in a subset of 17 candidate immune markers measured in peripheral blood of patients with ME/CFS and healthy control subjects before, during, and after a maximal exercise challenge. A set of 26 competing numerical models satisfied these data to within 5% error. FINDINGS: Mechanistically informed predictions of endocrine and immune markers that were either unmeasured or exhibited high subject-to-subject variability pointed to possible context-specific overexpression in ME/CFS at rest of corticotropin-releasing hormone, chemokine (C-X-C motif) ligand 8, estrogen, follicle-stimulating hormone (FSH), gonadotropin-releasing hormone 1, interleukin (IL)-23, and luteinizing hormone, and underexpression of adrenocorticotropic hormone, cortisol, interferon-γ, IL-10, IL-17, and IL-1α. Simulations of rintatolimod and rituximab treatment predicted a shift in the repertoire of available endocrine-immune regulatory regimens. Rintatolimod was predicted to make available substantial remission in a significant subset of subjects, in particular those with low levels of IL-1α, IL-17, and cortisol; intermediate levels of progesterone and FSH; and high estrogen levels. Rituximab treatment was predicted to support partial remission in a smaller subset of patients with ME/CFS, specifically those with low norepinephrine, IL-1α, chemokine (C-X-C motif) ligand 8, and cortisol levels; intermediate FSH and gonadotropin-releasing hormone 1 levels; and elevated expression of tumor necrosis factor-α, luteinizing hormone, IL-12, and B-cell activation. IMPLICATIONS: Applying a rigorous filter of known signaling mechanisms to experimentally measured immune marker expression in ME/CFS has highlighted potential new context-specific markers of illness. These novel endocrine and immune markers may offer useful candidates in delineating new subtypes of ME/CFS and may inform on refinements to the inclusion criteria and instrumentation of new and ongoing trials involving rintatolimod and rituximab treatment protocols.

Treatment Avenues in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Split-gender Pharmacogenomic Study of Gene-expression Modules.

PURPOSE: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating multisymptom illness impacting up to 1 million people in the United States. As the pathogenesis and etiology of this complex condition are unclear, prospective treatments are limited. Identifying US Food and Drug Administration-approved drugs that may be repositioned as treatments for ME/CFS may offer a rapid and cost-effective solution. METHODS: Here we used gene-expression data from 33 patients with Fukuda-defined ME/CFS (23 females, 10 males) and 21 healthy demographically comparable controls (15 females, 6 males) to identify differential expression of predefined gene-module sets based on nonparametric statistics. Differentially expressed gene modules were then annotated via over-representation analysis using the Consensus Pathway database. Differentially expressed modules were then regressed onto measures of fatigue and cross-referenced with drug atlas and pharmacogenomics databases to identify putative treatment agents. FINDINGS: The top 1% of modules identified in males indicated small effect sizes in modules associated with immune regulation and mitochondrial dysfunction. In females, modules identified included those related to immune factors and cardiac/blood factors, returning effect sizes ranging from very small to intermediate (0.147 < Cohen δ < 0.532). Regression analysis indicated that B-cell receptors, T-cell receptors, tumor necrosis factor α, transforming growth factor ß, and metabolic and cardiac modules were strongly correlated with multiple composite measures of fatigue. Cross-referencing identified genes with pharmacogenomics data indicated immunosuppressants as potential treatments of ME/CFS symptoms. IMPLICATIONS: The findings from our analysis suggest that ME/CFS symptoms are perpetuated by immune dysregulation that may be approached via immune modulation-based treatment strategies.

Pharmaceutical Interventions in Chronic Fatigue Syndrome: A Literature-based Commentary.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disorder characterized by prolonged periods of fatigue, chronic pain, depression, and a complex constellation of other symptoms. Currently, ME/CFS has no known cause, nor are the mechanisms of illness well understood. Therefore, with few exceptions, attempts to treat ME/CFS have been directed mainly toward symptom management. These treatments include antivirals, pain relievers, antidepressants, and oncologic agents as well as other single-intervention treatments. Results of these trials have been largely inconclusive and, in some cases, contradictory. Contributing factors include a lack of well-designed and -executed studies and the highly heterogeneous nature of ME/CFS, which has made a single etiology difficult to define. Because the majority of single-intervention treatments have shown little efficacy, it may instead be beneficial to explore broader-acting combination therapies in which a more focused precision-medicine approach is supported by a systems-level analysis of endocrine and immune co-regulation.

Associations Among Trajectories of Sleep Disturbance, Depressive Symptomology and 24-Hour Urinary Cortisol in HIV+ Women Following a Stress Management Intervention.

Objective: The burden of sleep disturbance and depressive symptomology is high for persons living with HIV and particularly so for women. While cognitive behavioral stress management (CBSM) is shown to reduce symptoms of depression and 24-hr urinary free cortisol output (CORT) in HIV+ men, less is known about the effects of CBSM on mood and concomitant sleep disturbance in HIV+ women. The study aim is to model longitudinal change in sleep disturbance, depressive symptomology, and CORT for HIV+ women exposed to a 12-week CBSM intervention or control condition. Methods: Self-reported sleep quality and depressive symptomology, along with CORT, was collected from surveys at baseline and approximately every three months thereafter for nine months from 130 HIV+ women (Mage = 38.44, SD = 7.73). The data was used to specify a parallel process latent growth model with CORT as a time-varying covariate. Results: The model showed acceptable fit. There was a linear decline in sleep disturbance (ß = -0.32, p < .05) and logarithmic decline in depressive symptomology (ß = -0.33, p < .05) for those receiving the intervention. Decline in sleep disturbance predicted lower CORT at nine months. Furthermore, having less depressive symptoms at baseline was associated with lower initial levels of sleep disturbance and greater improvement in sleep quality over time. There was no discernible association between sleep and mood disturbance in the control group. Across groups, there was a consistent association between older age and greater sleep disturbance (r = 0.34, p < .01). Conclusion: Sleep disturbance appears to be a behavioral target for CBSM in HIV+ women although older age, preintervention levels of depressive mood, and time-varying levels of CORT output may limit improvement in sleep quality over time.

Identification of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-associated DNA methylation patterns.

BACKGROUND: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition involving multiple organ systems and characterized by persistent/relapsing debilitating fatigue, immune dysfunction, neurological problems, and other symptoms not curable for at least 6 months. Disruption of DNA methylation patterns has been tied to various immune and neurological diseases; however, its status in ME/CFS remains uncertain. Our study aimed at identifying changes in the DNA methylation patterns that associate with ME/CFS. METHODS: We extracted genomic DNA from peripheral blood mononuclear cells from 13 ME/CFS study subjects and 12 healthy controls and measured global DNA methylation by ELISA-like method and site-specific methylation status using Illumina MethylationEPIC microarrays. Pyrosequencing validation included 33 ME/CFS cases and 31 controls from two geographically distant cohorts. RESULTS: Global DNA methylation levels of ME/CFS cases were similar to those of controls. However, microarray-based approach allowed detection of 17,296 differentially methylated CpG sites in 6,368 genes across regulatory elements and within coding regions of genes. Analysis of DNA methylation in promoter regions revealed 307 differentially methylated promoters. Ingenuity pathway analysis indicated that genes associated with differentially methylated promoters participated in at least 15 different pathways mostly related to cell signaling with a strong immune component. CONCLUSIONS: This is the first study that has explored genome-wide epigenetic changes associated with ME/CFS using the advanced Illumina MethylationEPIC microarrays covering about 850,000 CpG sites in two geographically distant cohorts of ME/CFS cases and matched controls. Our results are aligned with previous studies that indicate a dysregulation of the immune system in ME/CFS. They also suggest a potential role of epigenetic de-regulation in the pathobiology of ME/CFS. We propose screening of larger cohorts of ME/CFS cases to determine the external validity of these epigenetic changes in order to implement them as possible diagnostic markers in clinical setting.

Psychoneuroimmunology and Natural Killer Cells: The Chromium-Release Whole-Blood Assay.

Natural killer (NK) cells are an essential component of innate immunity. These lymphocytes are also sensitive barometers of the effects of endogenous and exogenous stressors on the immune system. This chapter describes a chromium (51Cr)-release bioassay designed to measure to the target cell killing capacity of NK cells (NKCC). Key features of the cytotoxicity assay are that it is done with whole blood and that numbers of effector cells are determined for each sample by flow cytometry and lymphocyte count. Effector cells are defined as CD3-CD56+ lymphocytes. Target cells are the K562 erythroleukemia cell line. Killing capacity is defined as number of target cells killed per effector cell, at an effector cell/target cell ratio of 1:1 during a 4-h in vitro assay.

Depression, evening salivary cortisol and inflammation in chronic fatigue syndrome: A psychoneuroendocrinological structural regression model.

INTRODUCTION: Chronic Fatigue Syndrome (CFS) is a poorly understood illness that is characterized by diverse somatic symptoms, hypothalamic pituitary adrenal (HPA) axis dysfunction and heightened inflammatory indicators. These symptoms are often exacerbated and accompanied by psychological distress states and depression. Since depression is known to be associated with HPA axis dysfunction and greater inflammation, a psychoneuroendocrinological (PNE) model of inflammation was examined in persons diagnosed with CFS in order to uncover underlying biopsychosocial mechanisms in this poorly understood chronic illness. METHODS: Baseline data were drawn from two randomized controlled trials testing the efficacy of different forms of psychosocial intervention, and included psychological questionnaires, di-urnal salivary cortisol, and blood samples. Data were analyzed with structural equation modeling (SEM). RESULTS: The sample (N=265) was mostly middle-aged (Mage=49.36±10.9, range=20-73years), Caucasian (67.7%), female (81.7%), highly educated (85.5% completed some college, college, or graduate program), and depressed (CES-D M=23.87±12.02, range 2-57). The SEM supporting a psychoneuroendocrinological model of immune dysregulation in CFS fit the data χ2 (12)=17.725, p=0.1243, RMSEA=0.043, CFI=0.935, SRMR=0.036. Depression was directly related to evening salivary cortisol and inflammation, such that higher evening cortisol predicted greater depressive symptoms (ß=0.215, p<0.01) and higher pro-inflammatory cytokines (interleukin-2 [IL-2], IL-6, and tumor necrosis factor-alpha [TNF-α] levels (ß=0.185, p<0.05), when controlling for covariates. DISCUSSION: Results highlight the role of depression, cortisol and inflammation in possible biological mechanisms involved in the pathophysiology of CFS. Time-lagged, longitudinal analyses are needed to fully explore these relationships.

Myalgic encephalomyelitis/chronic fatigue syndrome and gulf war illness patients exhibit increased humoral responses to the herpesviruses-encoded dUTPase: Implications in disease pathophysiology.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Gulf War Illness (GWI) are debilitating diseases with overlapping symptomology and there are currently no validated tests for definitive diagnosis of either syndrome. While there is evidence supporting the premise that some herpesviruses may act as possible triggers of ME/CFS, the involvement of herpesviruses in the pathophysiology of GWI has not been studied in spite of a higher prevalence of ME/CFS in these patients. We have previously demonstrated that the deoxyuridine triphosphate nucleotidohydrolases (dUTPase) encoded by Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), and varicella-zoster virus (VZV) possess novel functions in innate and adaptive immunity. The results of this study demonstrate that a significant percentage of patients with ME/CFS (30.91-52.7%) and GWI (29.34%) are simultaneously producing antibodies against multiple human herpesviruses-encoded dUTPases and/or the human dUTPase when compared to controls (17.21%). GWI patients exhibited significantly higher levels of antibodies to the HHV-6 and human dUTPases than controls (P = 0.0053 and P = 0.0036, respectively), while the ME/CFS cohort had higher anti-EBV-dUTPase antibodies than in both GWI patients (P = 0.0008) and controls (P < 0.0001) as well as significantly higher anti-human dUTPase antibodies than in controls (P = 0.0241). These results suggest that screening of patients' sera for the presence of various combinations of anti-dUTPase antibodies could be used as potential biomarkers to help identify/distinguish patients with these syndromes and better direct treatment.

Change in urinary cortisol excretion mediates the effect of angry/hostile mood on 9 month diastolic blood pressure in HIV+ adults.

Cardiovascular disease is a growing concern in HIV disease management and nearly 1 out of 3 persons living with the virus is hypertensive. Biobehavioral factors such as anger, hostility, and HPA axis reactivity are emperically linked to blood pressure regulation. Whether HPA axis or mood disturbance increases risk for hypertension remains unclear in HIV disease. The aim of this study was to determine whether 9-month change in angry/hostile mood predicts alterations in systolic (SBP) or diastolic blood pressure (DBP), and whether this change is mediated by 24-h urinary cortisol (CORT) output. Sixty-one HIV positive adults, aged 41.1 ± 8.6 years, assigned to the control condition of a stress management intervention provided blood samples, 24-h urine specimens, blood pressure in-office, and self-reported mood at baseline and a 9-month follow-up. CORT was tested as a mediator in two separate models controlling for baseline BP, CD4 count, HIV-1 viral load, protease inhibitor use, body mass index, smoking status, and family history of cardiometabolic disease. Increase in angry/hostile mood was associated with greater SBP (ß = 0.33, CI 0.09, 0.56, p = 0.01) and DBP (ß = 0.39, CI 0.16, 0.62, p < 0.001) at follow-up. CORT partially mediated the effect of angry/hostile mood on DBP (ß = 0.28, CI 0.03, 0.54, p = 0.03). Change in CORT was not related to SBP (ß = 0.12, CI -0.20, 0.44, p = 0.46). The final mediation model accounted for 41.2% of the variance in 9-month DBP. Angry or hostile mood may contribute to increased risk for hypertension in persons treated for HIV via disturbance of the HPA-axis.

Telephone-administered versus live group cognitive behavioral stress management for adults with CFS.

OBJECTIVE: Chronic fatigue syndrome (CFS) symptoms have been shown to be exacerbated by stress and ameliorated by group-based psychosocial interventions such as cognitive behavioral stress management (CBSM). Still, patients may have difficulty attending face-to-face groups. This study compared the effects of a telephone-delivered (T-CBSM) vs a live (L-CBSM) group on perceived stress and symptomology in adults with CFS. METHODS: Intervention data from 100 patients with CFS (mean age 50years; 90% female) participating in T-CBSM (N=56) or L-CBSM (N=44) in previously conducted randomized clinical trials were obtained. Perceived Stress Scale (PSS) and the Centers for Disease Control and Prevention symptom checklist scores were compared with repeated measures analyses of variance in adjusted and unadjusted analyses. RESULTS: Participants across groups showed no differences in most demographic and illness variables at study entry and had similar session attendance. Both conditions showed significant reductions in PSS scores, with L-CBSM showing a large effect (partial ε2=0.16) and T-CBSM a medium effect (partial ε2=0.095). For CFS symptom frequency and severity scores, L-CBSM reported large effect size improvements (partial ε2=0.19-0.23), while T-CBSM showed no significant changes over time. CONCLUSIONS: Two different formats for delivering group-based CBSM-live and telephone-showed reductions in perceived stress among patients with CFS. However, only the live format was associated with physical symptom improvements, with specific effects on post-exertional malaise, chills, fever, and restful sleep. The added value of the live group format is discussed, along with implications for future technology-facilitated group interventions in this population.

Poor sleep quality is associated with greater circulating pro-inflammatory cytokines and severity and frequency of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) symptoms in women.

OBJECTIVE: Poor sleep quality has been linked to inflammatory processes and worse disease outcomes in the context of many chronic illnesses, but less is known in conditions such as chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). This study examines the relationships between sleep quality, pro-inflammatory cytokines, and CFS/ME symptoms. METHODS: Sixty women diagnosed with CFS/ME were assessed using the Pittsburgh Sleep Quality Index (PSQI), Fatigue Symptom Inventory (FSI) and Center for Disease Control and Prevention (CDC)-based CFS/ME symptom questionnaires. Circulating plasma pro-inflammatory cytokine levels were measured by ELISA. Multiple regression analyses examined associations between sleep, cytokines and symptoms, controlling for age, education, and body mass index. RESULTS: Poor sleep quality (PSQI global score) was associated with greater pro-inflammatory cytokine levels: interleukin-1ß (IL-1ß) (ß=0.258, p=0.043), IL-6 (ß=0.281, p=0.033), and tumor necrosis factor-alpha (TNF-α) (ß=0.263, p=0.044). Worse sleep quality related to greater fatigue severity (ß=0.395, p=0.003) and fatigue-related interference with daily activities (ß=0.464, p<0.001), and more severe and frequent CDC-defined core CFS/ME symptoms (ß=0.499, p<0.001, and ß=0.556, p<0.001, respectively). CONCLUSIONS: Results underscore the importance of managing sleep-related difficulties in this patient population. Further research is needed to identify the etiology of sleep disruptions in CFS/ME and mechanistic factors linking sleep quality to symptom severity and inflammatory processes.

Tracking post-infectious fatigue in clinic using routine Lab tests.

BACKGROUND: While biomarkers for chronic fatigue syndrome (CFS) are beginning to emerge they typically require a highly specialized clinical laboratory. We hypothesized that subsets of commonly measured laboratory markers used in combination could support the diagnosis of post-infectious CFS (PI-CFS) in adolescents following infectious mononucleosis (IM) and help determine who might develop persistence of symptoms. METHODS: Routine clinical laboratory markers were collected prospectively in 301 mono-spot positive adolescents, 4 % of whom developed CFS (n = 13). At 6, 12, and 24 months post-diagnosis with IM, 59 standard tests were performed including metabolic profiling, liver enzyme panel, hormone profiles, complete blood count (CBC), differential white blood count (WBC), salivary cortisol, and urinalysis. Classification models separating PI-CFS from controls were constructed at each time point using stepwise subset selection. RESULTS: Lower ACTH levels at 6 months post-IM diagnosis were highly predictive of CFS (AUC p = 0.02). ACTH levels in CFS overlapped with healthy controls at 12 months, but again showed a trend towards a deficiency at 24 months. Conversely, estradiol levels depart significantly from normal at 12 months only to recover at 24 months (AUC p = 0.02). Finally, relative neutrophil count showed a significant departure from normal at 24 months in CFS (AUC p = 0.01). Expression of these markers evolved differently over time between groups. CONCLUSIONS: Preliminary results suggest that serial assessment of stress and sex hormones as well as the relative proportion of innate immune cells measured using standard clinical laboratory tests may support the diagnosis of PI-CFS in adolescents with IM.

Illness progression in chronic fatigue syndrome: a shifting immune baseline.

BACKGROUND: Validation of biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) across data sets has proven disappointing. As immune signature may be affected by many factors, our objective was to explore the shift in discriminatory cytokines across ME/CFS subjects separated by duration of illness. METHODS: Cytokine expression collected at rest across multiple studies for female ME/CFS subjects (i) 18 years or younger, ill for 2 years or less (n = 18), (ii) 18-50 years of age, ill for 7 years (n = 22), and (iii) age 50 years or older (n = 28), ill for 11 years on average. Control subjects were matched for age and body mass index (BMI). Data describing the levels of 16 cytokines using a chemiluminescent assay was used to support the identification of separate linear classification models for each subgroup. In order to isolate the effects of duration of illness alone, cytokines that changed significantly with age in the healthy control subjects were excluded a priori. RESULTS: Optimal selection of cytokines in each group resulted in subsets of IL-1α, 6, 8, 15 and TNFα. Common to any 2 of 3 groups were IL-1α, 6 and 8. Setting these 3 markers as a triple screen and adjusting their contribution according to illness duration sub-groups produced ME/CFS classification accuracies of 75-88 %. The contribution of IL-1α, higher in recently ill adolescent ME/CFS subjects was progressively less important with duration. While high levels of IL-8 screened positive for ME/CFS in the recently afflicted, the opposite was true for subjects ill for more than 2 years. Similarly, while low levels of IL-6 suggested early ME/CFS, the reverse was true in subjects over 18 years of age ill for more than 2 years. CONCLUSIONS: These preliminary results suggest that IL-1α, 6 and 8 adjusted for illness duration may serve as robust biomarkers, independent of age, in screening for ME/CFS.

Stress management skills, cortisol awakening response, and post-exertional malaise in Chronic Fatigue Syndrome.

Chronic Fatigue Syndrome (CFS) is characterized in part by debilitating fatigue typically exacerbated by cognitive and/or physical exertion, referred to as post-exertional malaise (PEM). In a variety of populations, the cortisol awakening response (CAR) has stood out as a marker of endocrine dysregulation relevant to the experience of fatigue, and may therefore be particularly relevant in CFS. This is the first study to examine PEM and the CAR in a sample of individuals with CFS. The CAR has also been established as a stress-sensitive measure of HPA axis functioning. It follows that better management of stress could modulate the CAR, and in turn PEM. In this cross-sectional study, we hypothesized that greater Perceived Stress Management Skills (PSMS) would relate to lower reports of PEM, via the impact of PSMS on the CAR. A total of 117 adults (72% female) with a CFS diagnosis completed self-report measures of PSMS and PEM symptomatology and a two-day protocol of saliva collection. Cortisol values from awakening and 30 min post-awakening were used to compute the CAR. Regression analyses revealed that greater PSMS related to greater CAR and greater CAR related to less PEM severity. Bootstrapped analyses revealed an indirect effect of PSMS on PEM via the CAR, such that greater PSMS related to less PEM, via a greater CAR. Future research should examine these trends longitudinally and whether interventions directed at improving stress management skills are accompanied by improved cortisol regulation and less PEM in individuals with CFS.

A role for homeostatic drive in the perpetuation of complex chronic illness: Gulf War Illness and chronic fatigue syndrome.

A key component in the body's stress response, the hypothalamic-pituitary-adrenal (HPA) axis orchestrates changes across a broad range of major biological systems. Its dysfunction has been associated with numerous chronic diseases including Gulf War Illness (GWI) and chronic fatigue syndrome (CFS). Though tightly coupled with other components of endocrine and immune function, few models of HPA function account for these interactions. Here we extend conventional models of HPA function by including feed-forward and feedback interaction with sex hormone regulation and immune response. We use this multi-axis model to explore the role of homeostatic regulation in perpetuating chronic conditions, specifically GWI and CFS. An important obstacle in building these models across regulatory systems remains the scarcity of detailed human in vivo kinetic data as its collection can present significant health risks to subjects. We circumvented this using a discrete logic representation based solely on literature of physiological and biochemical connectivity to provide a qualitative description of system behavior. This connectivity model linked molecular variables across the HPA axis, hypothalamic-pituitary-gonadal (HPG) axis in men and women, as well as a simple immune network. Inclusion of these interactions produced multiple alternate homeostatic states and sexually dimorphic responses. Experimental data for endocrine-immune markers measured in male GWI subjects showed the greatest alignment with predictions of a naturally occurring alternate steady state presenting with hypercortisolism, low testosterone and a shift towards a Th1 immune response. In female CFS subjects, expression of these markers aligned with an alternate homeostatic state displaying hypocortisolism, high estradiol, and a shift towards an anti-inflammatory Th2 activation. These results support a role for homeostatic drive in perpetuating dysfunctional cortisol levels through persistent interaction with the immune system and HPG axis. Though coarse, these models may nonetheless support the design of robust treatments that might exploit these regulatory regimes.

A comparison of sex-specific immune signatures in Gulf War illness and chronic fatigue syndrome.

BACKGROUND: Though potentially linked to the basic physiology of stress response we still have no clear understanding of Gulf War Illness (GWI), a debilitating condition presenting complex immune, endocrine and neurological symptoms. Here we compared male (n = 20) and female (n = 10) veterans with GWI separately against their healthy counterparts (n = 21 male, n = 9 female) as well as subjects with chronic fatigue syndrome/ myalgic encephalomyelitis (CFS/ME) (n = 12 male, n = 10 female). METHODS: Subjects were assessed using a Graded eXercise Test (GXT) with blood drawn prior to exercise, at peak effort (VO2 max) and 4-hours post exercise. Using chemiluminescent imaging we measured the concentrations of IL-1a, 1b, 2, 4, 5, 6, 8, 10, 12 (p70), 13, 15, 17 and 23, IFNγ, TNFα and TNFß in plasma samples from each phase of exercise. Linear classification models were constructed using stepwise variable selection to identify cytokine co-expression patterns characteristic of each subject group. RESULTS: Classification accuracies in excess of 80% were obtained using between 2 and 5 cytokine markers. Common to both GWI and CFS, IL-10 and IL-23 expression contributed in an illness and time-dependent manner, accompanied in male subjects by NK and Th1 markers IL-12, IL-15, IL-2 and IFNγ. In female GWI and CFS subjects IL-10 was again identified as a delineator but this time in the context of IL-17 and Th2 markers IL-4 and IL-5. Exercise response also differed between sexes: male GWI subjects presented characteristic cytokine signatures at rest but not at peak effort whereas the opposite was true for female subjects. CONCLUSIONS: Though individual markers varied, results collectively supported involvement of the IL-23/Th17/IL-17 axis in the delineation of GWI and CFS in a sex-specific way.