Utility of the blood for gene expression profiling and biomarker discovery in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating illness lacking consistent anatomic lesions and eluding conventional laboratory diagnosis. Demonstration of the utility of the blood for gene expression profiling and biomarker discovery would have implications into the pathophysiology of CFS. The objective of this study was to determine if gene expression profiles of peripheral blood mononuclear cells (PMBCs) could distinguish between subjects with CFS and healthy controls.

Total RNA from PBMCs of five CFS cases and seventeen controls was labeled and hybridized to 1764 genes on filter arrays. Gene intensity values were analyzed by various classification algorithms and nonparametric statistical methods. The classification algorithms grouped the majority of the CFS cases together, and distinguished them from the healthy controls.

Eight genes were differentially expressed in both an age-matched case-control analysis and when comparing all CFS cases to all controls. Several of the differentially expressed genes are associated with immunologic functions (e.g., CMRF35 antigen, IL-8, HD protein) and implicate immune dysfunction in the pathophysiology of CFS. These results successfully demonstrate the utility of the blood for gene expression profiling to distinguish subjects with CFS from healthy controls and for identifying genes that could serve as CFS biomarkers.

 

Source: Vernon SD, Unger ER, Dimulescu IM, Rajeevan M, Reeves WC. Utility of the blood for gene expression profiling and biomarker discovery in chronic fatigue syndrome. Dis Markers. 2002;18(4):193-9. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3851413/ (Full article)

 

Blood flow and muscle metabolism in chronic fatigue syndrome

Abstract:

The purpose of this study was to determine if chronic fatigue syndrome (CFS) is associated with reduced blood flow and oxidative delivery to skeletal muscle. Patients with CFS according to CDC (Center for Disease Control) criteria ( n =19) were compared with normal sedentary subjects ( n =11). Muscle blood flow was measured with Doppler ultrasound after cuff ischaemia and exercise. Muscle oxygen delivery was measured as the rate of post-exercise and post-ischaemic oxygen-haem resaturation. Oxygen-haem resaturation was measured in the medial gastrocnemius muscle using continuous wavelength near-IR spectroscopy. Muscle metabolism was measured using (31)P magnetic resonance spectroscopy. CFS patients and controls were not different in the peak blood flow after cuff ischaemia, the rate of recovery of phosphocreatine after submaximal exercise, and the rate of recovery of oxygen saturation after cuff ischaemia. In conclusion, CFS patients showed no deficit in blood flow or oxidative metabolism. This suggests that CFS symptoms do not require abnormal peripheral function.

 

Source: McCully KK, Smith S, Rajaei S, Leigh JS Jr, Natelson BH. Blood flow and muscle metabolism in chronic fatigue syndrome.  Clin Sci (Lond). 2003 Jun;104(6):641-7. http://www.ncbi.nlm.nih.gov/pubmed/12589704

 

The head-up tilt test with haemodynamic instability score in diagnosing chronic fatigue syndrome

Abstract:

BACKGROUND: Studying patients with chronic fatigue syndrome (CFS), we have developed a method that uses a head-up tilt test (HUTT) to estimate BP and HR instability during tilt, expressed as a ‘haemodynamic instability score’ (HIS).

AIM: To assess HIS sensitivity and specificity in the diagnosis of CFS.

DESIGN:  Prospective controlled study.

METHODS: Patients with CFS (n=40), non-CFS chronic fatigue (n=73), fibromyalgia (n=41), neurally mediated syncope (n=58), generalized anxiety disorder (n=28), familial Mediterranean fever (n=50), arterial hypertension (n=28), and healthy subjects (n=59) were evaluated with a standardized head-up tilt test (HUTT). The HIS was calculated from blood pressure (BP) and heart rate (HR) changes during the HUTT.

RESULTS: The tilt was prematurely terminated in 22% of CFS patients when postural symptoms occurred and the HIS could not be calculated. In the remainder, the median(IQR) HIS values were: CFS +2.14(4.67), non-CFS fatigue -3.98(5.35), fibromyalgia -2.81(2.62), syncope -3.7(4.36), generalized anxiety disorder -0.21(6.05), healthy controls -2.66(3.14), FMF -5.09(6.41), hypertensives -5.35(2.74) (p<0.0001 vs. CFS in all groups, except for anxiety disorder, p=NS). The sensitivity for CFS at HIS >-0.98 cut-off was 90.3% and the overall specificity was 84.5%.

DISCUSSION: There is a particular dysautonomia in CFS that differs from dysautonomia in other disorders, characterized by HIS >-0.98. The HIS can reinforce the clinician’s diagnosis by providing objective criteria for the assessment of CFS, which until now, could only be subjectively inferred.

Comment in:

The head-up tilt test for diagnosing chronic fatigue syndrome. [QJM. 2003]

Assessing chronic fatigue. [QJM. 2003]

 

Source: Naschitz JE, Rosner I, Rozenbaum M, Naschitz S, Musafia-Priselac R, Shaviv N, Fields M, Isseroff H, Zuckerman E, Yeshurun D, Sabo E. The head-up tilt test with haemodynamic instability score in diagnosing chronic fatigue syndrome.  QJM. 2003 Feb;96(2):133-42. http://qjmed.oxfordjournals.org/content/96/2/133.long (Full article)

 

A six-month trial of valacyclovir in the Epstein-Barr virus subset of chronic fatigue syndrome: improvement in left ventricular function

Abstract:

This study was designed to determine safety and efficacy of a 6-month trial of valacyclovir in single-virus Epstein-Barr virus (EBV) persistent infection. Phase I of this study used four specific criteria to define a subset of patients with chronic fatigue syndrome (CFS). In the second phase, myocardial dynamics were measured by MUGA rest/stress radionuclide ventriculographic (RVG) examinations pre- and posttreatment with valacyclovir.

In phase I, a trial was performed in 19 consecutive CFS patients with the following diagnostic conditions: patients met criteria for diagnosis of CFS; they had had CFS for less than 1 year. They demonstrated repetitively abnormal oscillating T waves (ischemic or flat) at 24-h Holter monitoring; and they had elevated serum IgM antibody titers to EBV viral capsid antigen and/or total diffuse early antigen as measured by the enzyme-linked immunosorbent assay method.

The treatment group comprised 10 CFS patients with no serum antibodies to human cytomegalovirus, but the control group (nine CFS patients) had, additionally, high titers of serum antibodies (IgG) to conformational structural antigens of human cytomegalovirus. Both the parallel treatment and control CFS groups received valacyclovir 1.0-1.5 gm q.6.h. for 6 months.

This valacyclovir dose achieved serum acyclovir C(max) of > 7 microm and high antiviral activity versus EBV (IC(50) of 4.4-13.3 m). In phase II, six additional CFS patients met the same four criteria as the 19 CFS patients in phase I. They had, however, been ill for a mean of 55.8 months. Thus, 25 CFS patients comprise this study.

The studies were carried out at a single outpatient practice in Birmingham, MI, U.S.A. Before initiating valacyclovir, and after 6 months of treatment, clinical and laboratory observations were made. The CFS Energy Index point score (Table I) was used to record each CFS patient’s functional capacity at baseline and after 1, 3 and 6 months of valacyclovir. Energy Index point scores, as well as EBV and human cytomegalovirus serum antibody titers were assessed.

In the second phase, left ventricular dynamics were repeated after 6 months of treatment with valacyclovir. We concluded that the 16 CFS patients (included in both phases of this study) with EBV-persistent infection (EBV single-virus subset) are improved after 6 months of continuous pharmacokinetic dosing with valacyclovir. Nine CFS patients with EBV/human cytomegalovirus co-infection did not benefit from 6 months of similar treatment. Valacyclovir is not an effective anti-human cytomegalovirus antiviral drug. Unimproved CFS patients with co-infections EBV and human cytomegalovirus may require combined treatment with valacyclovir and another drug more active against human cytomegalovirus.

This preliminary trial, with a small number of patients, may be critical to an appropriately designed larger, double-blind, placebo-controlled trial.

Copyright 2002 Prous Science

 

Source: Lerner AM, Beqaj SH, Deeter RG, Dworkin HJ, Zervos M, Chang CH, Fitzgerald JT, Goldstein J, O’Neill W. A six-month trial of valacyclovir in the Epstein-Barr virus subset of chronic fatigue syndrome: improvement in left ventricular function. Drugs Today (Barc). 2002 Aug;38(8):549-61. http://www.ncbi.nlm.nih.gov/pubmed/12582420

 

Assessment of cardiovascular reactivity by fractal and recurrence quantification analysis of heart rate and pulse transit time

Abstract:

Methods used for the assessment of cardiovascular reactivity are flawed by nonlinear dynamics of the cardiovascular responses to stimuli. In an attempt to address this issue, we utilized a short postural challenge, recorded beat-to-beat heart rate (HR) and pulse transit time (PTT), assessed the data by fractal and recurrence quantification analysis, and processed the obtained variables by multivariate statistics. A 10-min supine phase of the head-up tilt test was followed by recording 600 cardiac cycles on tilt, that is, 5-10 min.

Three groups of patients were studied, each including 20 subjects matched for age and gender–healthy subjects, patients with essential hypertension (HT), and patients with chronic fatigue syndrome (CFS). The latter group was studied on account of the well-known dysautonomia of CFS patients, which served as contrast against the cardiovascular reactivity of the healthy population. A total of 52 variables of the HR and PTT were determined in each subject.

The multivariate model identified the best predictors for the assessment of reactivity of healthy subjects vs CFS. Based on these predictors, the “Fractal & Recurrence Analysis-based Score” (FRAS) was calculated: FRAS=76.2+0.04*HR-supine-DET -12.9*HR-tilt-R/L -0.31*HR-tilt-s.d. -19.27*PTT-tilt-R/L -9.42*PTT-tilt-WAVE. The median values and IQR of FRAS in the groups were: healthy=-1.85 (IQR 1.89), hypertensives=+0.52 (IQR 5.78), and CFS=-24.2 (5.34) (HT vs healthy subjects: P=0.0036; HT vs CFS: P<0.0001). Since the FRAS differed significantly between the three groups, it appears likely that the FRAS may recognize phenotypes of cardiovascular reactivity.

 

Source: Naschitz JE, Rosner I, Shaviv N, Khorshidi I, Sundick S, Isseroff H, Fields M, Priselac RM, Yeshurun D, Sabo E.Erratum in: J Hum Hypertens. 2003 Aug;17(8):585. Itzhak, R [corrected to Rosner, I]. Assessment of cardiovascular reactivity by fractal and recurrence quantification analysis of heart rate and pulse transit time. J Hum Hypertens. 2003 Feb;17(2):111-8. http://www.ncbi.nlm.nih.gov/pubmed/12574789

 

Phantom lymphadenopathy. An association with chronic fatigue syndrome

Abstract:

Ten patients with self diagnosed enlarged lymph glands were referred to a general medicine outpatient clinic and careful examination did not confirm lymphadenopathy. All patients also complained of severe chronic fatigue associated with aches and miscellaneous somatic symptoms, and fulfilled criteria for diagnosis of chronic fatigue syndrome (CFS). Phantom lymphadenopathy may be a symptom in some people with CFS, and possible reasons for this are discussed.

Comment in: Phantom lymphadenopathy. An association with chronic fatigue syndrome. [Postgrad Med J. 2003]

 

Source: Shee CD. Phantom lymphadenopathy. An association with chronic fatigue syndrome. Postgrad Med J. 2003 Jan;79(927):59-60. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1742587/ (Full article)

 

Chronic fatigue syndrome in patients with macrophagic myofasciitis

Macrophagic myofasciitis (MMF), a condition first reported in France in 1998, is defined by the presence of a stereotyped and immunologically active lesion at deltoid muscle biopsy . It was recently demonstrated that this lesion is an indicator of long-term persistence of the immunologic adjuvant aluminum hydroxide within the cytoplasm of macrophages at the site of previous intramuscular (IM) injection. MMF is typically detected in patients with diffuse arthromyalgias that have appeared subsequent to aluminum hydroxide administration in the absence of a clearly defined anatomic substratum. Patients also report unexplained chronic fatigue. These manifestations are reminiscent of the so-called chronic fatigue syndrome (CFS), a poorly understood condition manifesting as disabling fatigue, musculoskeletal pain, sleep disturbance, impaired concentration, and headaches. The present study was conducted to determine the proportion of MMF patients fulfilling international criteria for CFS.

You can read the rest of this article here: http://onlinelibrary.wiley.com/doi/10.1002/art.10740/full

 

Source: Authier FJ, Sauvat S, Champey J, Drogou I, Coquet M, Gherardi RK. Chronic fatigue syndrome in patients with macrophagic myofasciitis. Arthritis Rheum. 2003 Feb;48(2):569-70. http://onlinelibrary.wiley.com/doi/10.1002/art.10740/full (Full article)

 

A measure of heart rate variability is sensitive to orthostatic challenge in women with chronic fatigue syndrome

Abstract:

The use of symptoms generated by head up tilt (HUT) is not a useful tool in identifying chronic fatigue syndrome (CFS). We investigated whether heart rate variability (HRV) assessed early during HUT might be useful. A sample of 46 female subjects (24 with CFS and 22 sedentary, age-matched healthy controls; CON) who had exhibited no difference in time to syncope during tilt was examined for HRV responses to 10 min of 70 degrees HUT after 5 min of baseline in the supine position. HRV data were analyzed by the method of coarse graining spectral analysis. Variables compared between groups included mean and standard deviation (SD(RRI)) of RR intervals (RRI), amplitudes of low- (A(LF); 0.04-0.15 Hz) and high-frequency (A(HF); >0.15 Hz) harmonic as well as aperiodic, fractal (A(FR); 1/f(beta)) spectral components, the spectral exponent beta, and the difference in these values between baseline and HUT for each subject.

In the supine baseline, only mean RRI was significantly (P < 0.01) lower in CFS than in CON. During HUT, however, mean RRI (P < 0.01), SD(RRI) (P < 0.01), A(HF) (P < 0.05), and A(FR) (P < 0.01) were significantly lower in CFS than in CON. When the difference in values between baseline and HUT for each subject was examined, only the difference for A(FR) (deltaA(FR)) was significantly (P < 0.01) lower in CFS than in CON, suggesting that A(FR)is a disease-specific response of HRV to HUT. When a cut-off level was set to deltaA(FR) = -2.7 msec, the sensitivity and the specificity in differentiating CFS from controls were 90% and 72%, respectively. The data suggest that a decrease in aperiodic fractal component of HRV in response to HUT can be used to differentiate patients with CFS from CON.

 

Source: Yamamoto Y, LaManca JJ, Natelson BH. A measure of heart rate variability is sensitive to orthostatic challenge in women with chronic fatigue syndrome. Exp Biol Med (Maywood). 2003 Feb;228(2):167-74. http://www.ncbi.nlm.nih.gov/pubmed/12563023

 

Chronic fatigue syndrome: a review

Abstract:

OBJECTIVE: Chronic fatigue syndrome is an illness characterized by disabling fatigue of at least 6 months, accompanied by several other symptoms. This review summarizes the current state of knowledge about chronic fatigue syndrome.

METHOD: The case definition, prevalence, clinical presentation, evaluation, and prognosis of chronic fatigue syndrome are discussed. Research on the pathophysiology and treatment of chronic fatigue syndrome is reviewed.

RESULTS: Chronic fatigue syndrome is diagnosed on the basis of symptoms. Patients with chronic fatigue syndrome experience significant functional impairment. Pathophysiological abnormalities exist across many domains, suggesting that chronic fatigue syndrome is a heterogeneous condition of complex and multifactorial etiology. Evidence also is beginning to emerge that chronic fatigue syndrome may be familial. Although chronic fatigue syndrome has significant symptom overlap and comorbidity with psychiatric disorders, several lines of research suggest that the illness may be distinct from psychiatric disorders. Patients’ perceptions, attributions, and coping skills, however, may help perpetuate the illness. Treatment for chronic fatigue syndrome is symptom-based and includes pharmacological and behavioral strategies. Cognitive behavior therapy and graded exercise can be effective in treating the fatigue and associated symptoms and disability.

CONCLUSIONS: Chronic fatigue syndrome is unlikely to be caused or maintained by a single agent. Findings to date suggest that physiological and psychological factors work together to predispose an individual to the illness and to precipitate and perpetuate the illness. The assessment and treatment of chronic fatigue syndrome should be multidimensional and tailored to the needs of the individual patient.

Comment in:

On chronic fatigue syndrome. [Am J Psychiatry. 2004]

On chronic fatigue syndrome. [Am J Psychiatry. 2004]

 

Source: Afari N, Buchwald D. Chronic fatigue syndrome: a review. Am J Psychiatry. 2003 Feb;160(2):221-36. http://www.ncbi.nlm.nih.gov/pubmed/12562565

 

Differential diagnosis for chronic fatigue syndrome

Comment on: Chronic fatigue syndrome: evaluation and treatment. [Am Fam Physician. 2002]

 

To the Editor: I have just read the recent article on chronic fatigue syndrome (CFS). While the authors present an excellent framework for the evaluation and management of patients with chronic fatigue, they have overlooked a differential diagnosis. Celiac disease, also known as gluten-sensitive enteropathy (GSE), may present as CFS and is highly treatable.

You can read the rest of this comment here:  http://www.aafp.org/afp/2003/0115/p252.html

 

Source: Nelsen DA Jr. Differential diagnosis for chronic fatigue syndrome. Am Fam Physician. 2003 Jan 15;67(2):252; author reply 252 http://www.aafp.org/afp/2003/0115/p252.html (Full article)