Category: Pathogenesis

Treatment of chronic fatigue syndrome with 5-HT3 receptor antagonists–preliminary results

Abstract:

OBJECTIVE: The serotonin system presumably is involved in the pathogenesis of chronic fatigue syndrome (CFS). Results from a few studies led to the hypothesis of a “postsynaptic hyperresponsiveness” in CFS. Therefore we intended to evaluate the efficacy of 5-HT3 receptor antagonists in the treatment of CFS.

PATIENTS AND METHODS: 2 patient groups (10 patients each; CFS according to the CDC classification criteria) received either oral tropisetron (5 mg once daily) or oral ondansetron (2 x 8 mg daily), open-labelled. Treatment duration was 15 days. Treatment response was evaluated by visual analog scales (VAS) for fatigue and capability.

RESULTS: 19 patients finished their respective study. In the tropisetron group 6/9 (VAS fatigue) and 7/9 (VAS capability) patients documented benefit, 8/10 rsp. 8/10 patients in the ondansetron group. The score changes (VAS before and after treatment) in case of response were more pronounced in the tropisetron group. The frequency of concomitant symptoms did not differ significantly in the treatment groups. The overall analysis of both studies showed a remarkable improvement (> or = 35%) of approximately one third of the patients in both VAS. Treatment was well tolerated.

CONCLUSION: Our preliminary results encourage to perform placebo-controlled, double-blind studies to further evaluate the efficacy of 5-HT3 receptor antagonists in the treatment of CFS.

Source: Späth M, Welzel D, Färber L. Treatment of chronic fatigue syndrome with 5-HT3 receptor antagonists–preliminary results. Scand J Rheumatol Suppl. 2000;113:72-7. http://www.ncbi.nlm.nih.gov/pubmed/11028837

The roles of orthostatic hypotension, orthostatic tachycardia, and subnormal erythrocyte volume in the pathogenesis of the chronic fatigue syndrome

Abstract:

BACKGROUND: Orthostatic hypotension during upright tilt is an important physical disorder in patients with chronic fatigue syndrome. We have tested its occurrence during prolonged standing, whether it is correctable, and whether reduced circulating erythrocyte volume is present.

METHODS: Fifteen patients were randomly selected from a large population of patients with chronic fatigue syndrome, studied, and observed for several years (by DSB). Blood pressure (BP) and heart rate (HR) measured with Dinamap every minute for 30 minutes supine and 60 minutes standing were compared with these findings in 15 healthy age- and gender-matched control subjects and later during lower body compression with military antishock trousers (MAST). Plasma catecholamines and circulating erythrocyte and plasma volumes were also measured by isotopic dilution methods.

RESULTS: Abnormal findings in the patients included excessive orthostatic reductions in systolic (P < 0.001) and diastolic BP (P < 0.001) and excessive orthostatic tachycardia (P < 0.01), together with presyncopal symptoms in 11 of the 15 patients and in none of the control subjects after standing for 60 min. Lower body compression with the MAST restored all orthostatic measurements to normal and overcame presyncopal symptoms within 10 min. Circulating erythrocyte but not plasma volumes were subnormal in the 12 women (P < 0.01) and plasma norepinephrine concentration rose excessively after standing for 10 min.

CONCLUSION: Delayed orthostatic hypotension and/or tachycardia caused by excessive gravitational venous pooling, which is correctable with external lower-body compression, together with subnormal circulating erythrocyte volume, are very frequent, although not invariably demonstrable, findings in moderate to severe chronic fatigue syndrome. When present, they may be involved in its pathogenesis.

 

Source: Streeten DH, Thomas D, Bell DS. The roles of orthostatic hypotension, orthostatic tachycardia, and subnormal erythrocyte volume in the pathogenesis of the chronic fatigue syndrome. Am J Med Sci. 2000 Jul;320(1):1-8. http://www.ncbi.nlm.nih.gov/pubmed/10910366

 

Chronic fatigue syndrome:objective criteria of metabolic defects

Abstract:

Multi-level system of defense mechanisms is studied in 206 normal subjects living in an ecologically unfavorable region and working at chemical plants. Control group consisted of 24 subjects living in en ecologically safe region. The content of total protein and albumin and its effective and binding capacity were decreased, while the content of medium molecular weight peptides increased in the blood of subjects exposed to technogenic environmental pollution. The detected shifts are regarded as a mechanism of development of chronic fatigue syndrome.

 

Source: Gil’miiarova FN, Radomskaia VM, Kretova IG, Vinogradova LN, Samykina LN, Sheshunov IV, Babichev AV, Sharafutdinova IuM, Ponomareva LA. Chronic fatigue syndrome:objective criteria of metabolic defects. Klin Lab Diagn. 1999 Feb;(2):9-11. [Article in Russian] http://www.ncbi.nlm.nih.gov/pubmed/10876679

 

Frequent HHV-6 reactivation in multiple sclerosis (MS) and chronic fatigue syndrome (CFS) patients

Abstract:

BACKGROUND: HHV-6 is a ubiquitous virus and its infection usually occurs in childhood and then becomes a latent infection. HHV-6 reactivation has been shown to play a role in the pathogenesis of AIDS and several other diseases.

OBJECTIVES: To determine what role HHV-6 infection or reactivation plays in the pathogenesis of multiple sclerosis (MS) and chronic fatigue syndrome (CFS).

RESULTS: Twenty-one MS and 35 CFS patients were studied and followed clinically. In these patients, we measured HHV-6 IgG and IgM antibody levels and also analyzed their peripheral blood mononuclear cells (PBMCs) for the presence of HHV-6, using a short term culture assay. In both MS and CFS patients, we found higher levels of HHV-6 IgM antibody and elevated levels of IgG antibody when compared to healthy controls. Seventy percent of the MS patients studied contained IgM antibodies for HHV-6 late antigens (capsid), while only 15% of the healthy donors (HD) and 20% of the patients with other neurological disorders (OND) had HHV-6 IgM antibodies. Higher frequency of IgM antibody was also detected in CFS patients (57.1%) compared to HD (16%). Moreover, 54% of CFS patients exhibited antibody to HHV-6 early protein (p41/38) compared to only 8.0% of the HD. Elevated IgG antibody titers were detected in both the MS and the CFS patients. PBMCs from MS, CFS and HD were analyzed in a short term culture assay in order to detect HHV-6 antigen expressing cells and to characterize the viral isolates obtained as either Variant A or B. Fifty-four percent of MS patients contained HHV-6 early and late antigen producing cells and 87% of HHV-6 isolates were Variant B. Isolates from CFS, patients were predominately Variant A (70%) and isolates from HD were predominately Variant B (67%). Moreover, one isolate from OND was also Variant B. Persistent HHV-6 infection was found in two CFS patients over a period of 2.5 years and HHV-6 specific cellular immune responses were detected in PBMCs from ten CFS patients.

CONCLUSION: In both MS and CFS patients, we found increased levels of HHV-6 antibody and HHV-6 DNA. A decrease in cellular immune responses was also detected in CFS patients. These data suggest that HHV-6 reactivation plays a role in the pathogenesis of these disorders.

 

Source: Ablashi DV, Eastman HB, Owen CB, Roman MM, Friedman J, Zabriskie JB, Peterson DL, Pearson GR, Whitman JE. Frequent HHV-6 reactivation in multiple sclerosis (MS) and chronic fatigue syndrome (CFS) patients. J Clin Virol. 2000 May;16(3):179-91. http://www.ncbi.nlm.nih.gov/pubmed/10738137

 

Chronic fatigue syndrome beginning suddenly occurs seasonally over the year

Abstract:

The fact that many patients with chronic fatigue syndrome (CFS) have an infectious like sudden onset to their illness has led to the hypothesis that CFS is a medical illness. If CFS were, on the other hand, a psychiatric disorder related to symptom amplification, one would expect illness onset to occur randomly over the calendar year.

This study tested that hypothesis with 69 CFS patients whose illness was on the more severe side of the illness spectrum; all patients reported sudden illness onset with the full syndrome of sore throat, fatigue/malaise, and diffuse achiness developing over no longer than a 2-day period. Date of illness onset was distinctly nonrandom. It peaked from November through January and was at its lowest from April through May. These data support the hypothesis that an infectious illness can trigger the onset of CFS.

 

Source: Zhang QW, Natelson BH, Ottenweller JE, Servatius RJ, Nelson JJ, De Luca J, Tiersky L, Lange G. Chronic fatigue syndrome beginning suddenly occurs seasonally over the year. Chronobiol Int. 2000 Jan;17(1):95-9. http://www.ncbi.nlm.nih.gov/pubmed/10672437

 

Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever

Abstract:

BACKGROUND: The role of viruses in the aetiology of both chronic fatigue syndrome (CFS) and depressive illness is uncertain.

METHOD: A prospective cohort study of 250 primary care patients, presenting with glandular fever or an ordinary upper respiratory tract infection (URTI).

RESULTS: The incidence of an acute fatigue syndrome was 47% at onset, after glandular fever, compared with 20% with an ordinary URTI (relative risk 2.3, 95% CI 1.3-4.1). The acute fatigue syndrome lasted a median (interquartile range) of eight weeks (4-16) after glandular fever, but only three weeks (2-4) after an URTI. The prevalence of CFS was 9-22% six months after glandular fever, compared with 0-6% following an ordinary URTI, with relative risks of 2.7-5.1. The most conservative measure of the incidence of CFS was 9% after glandular fever, compared with no cases after an URTI. A conservative estimate is that glandular fever accounts for 3113 (95% CI 1698-4528) new cases of CFS per annum in England and Wales. New episodes of major depressive disorder were triggered by infection, especially the Epstein-Barr virus, but lasted a median of only three weeks. No psychiatric disorder was significantly more prevalent six months after onset than before.

CONCLUSIONS: Glandular fever is a significant risk factor for both acute and chronic fatigue syndromes. Transient new major depressive disorders occur close to onset, but are not related to any particular infection if they last more than a month.

 

Source: White PD, Thomas JM, Amess J, Crawford DH, Grover SA, Kangro HO, Clare AW. Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever. Br J Psychiatry. 1998 Dec;173:475-81. http://www.ncbi.nlm.nih.gov/pubmed/9926075

 

Increased production of interleukin-6 by adherent and non-adherent mononuclear cells during ‘natural fatigue’ but not following ‘experimental fatigue’ in patients with chronic fatigue syndrome

Abstract:

In an investigator-blinded study, adherent (monocytes) and non-adherent cells (lymphocytes) from patients with chronic fatigue syndrome (CFS) were examined on two separate occasions (when feeling ‘fatigued’ and when feeling ‘rested’) for in vitro spontaneous, phytohemagglutinin- (PHA, for lymphocytes), and lipopolysaccharide- (LPS, for monocytes) induced production of IL-6 by ELISA assay.

A group of CFS patients and controls were also subjected to exercise-induced fatigue (‘experimental fatigue’) and IL-6 production was compared, in a double-blinded manner, prior to and following induction of fatigue.

A significant increase in spontaneous, PHA- and LPS-induced IL-6 secretion by both lymphocytes and monocytes was observed in CFS patients during ‘natural fatigue’ as compared to during state. However, no such changes in IL-6 production were observed during ‘experimental fatigue’.

These data suggest a role of IL-6 in natural symptomatology and perhaps in the pathogenesis of CFS. In addition, the data demonstrate that laboratory-induced fatigue (experimental fatigue) may not be a good model to study immunological changes in CFS; immunological parameters should be studied in a longitudinal manner during the natural course of the disease.

 

Source: Gupta S, Aggarwal S, Starr A. Increased production of interleukin-6 by adherent and non-adherent mononuclear cells during ‘natural fatigue’ but not following ‘experimental fatigue’ in patients with chronic fatigue syndrome. Int J Mol Med. 1999 Feb;3(2):209-13. http://www.ncbi.nlm.nih.gov/pubmed/9917531

 

Chronic fatigue syndrome in psychiatric patients: lifetime and premorbid personal history of physical health

Abstract:

OBJECTIVE: This preliminary report compares a group of chronic fatigue syndrome (CFS) patients and controls on several variables of potential significance in the etiology of CFS.

METHOD: The lifetime prevalence of reported physical disorders was compared among 46 CFS psychiatric patients, 92 relatively physically healthy psychiatric patients (C-I), and 46 psychiatric patients selected without regard to physical health (C-II). All patients were matched on age, sex, and psychiatric diagnosis and were drawn from the same psychiatric practice. The same groups were compared on a 7-point scale of lifetime physical health by three raters independently evaluating physical health narratives of the CFS patients up to the time of onset of CFS and that of the controls up to the corresponding age.

RESULTS: The CFS patients had a significantly higher reported lifetime prevalence of irritable bowel syndrome (IBS), infectious mononucleosis-like syndromes (IM), infectious mononucleosis-like syndromes two or more times (IM x 2), and herpes (other than genital or perioral herpes) than one or both control groups. The CFS group also had a higher incidence of allergic rhinitis or asthma, IBS, IM, and IM x 2 than the combined controls. On the independent ratings, the CFS patients had significantly more impaired physical health up to the time of onset of the CFS than C-I at a comparable age.

CONCLUSIONS: The findings suggest that a general health factor may be involved in the pathogenesis of some cases of CFS.

 

Source: Endicott NA. Chronic fatigue syndrome in psychiatric patients: lifetime and premorbid personal history of physical health. Psychosom Med. 1998 Nov-Dec;60(6):744-51. http://www.ncbi.nlm.nih.gov/pubmed/9847035

 

Multiplex PCR for the detection of Mycoplasma fermentans, M. hominis and M. penetrans in cell cultures and blood samples of patients with chronic fatigue syndrome

Abstract:

A multiplex polymerase chain reaction (PCR) was initially developed to detect the presence of mycoplasma genus DNA sequences in cell cultures and to differentiate between three human pathogenic mycoplasma species simultaneously. The assay in turn, proved to be a useful tool for the detection of mycoplasma infection in human DNA samples.

One set of oligonucleotide primers which are specific for a highly conserved region among all members of the genus mycoplasma along with three other primer sets which are specific for Mycoplasma fermentans, Mycoplasma hominis andMycoplasma penetrans species were used in this assay. The sensitivity of detection was determined by infecting peripheral blood mononuclear cells (PBMC) of healthy individuals with known bacterial copy numbers from each species, extracting the DNA, and subjecting 1 microgram of DNA from each sample to 40 cycles of amplification. By using agarose gel electrophoresis the detection level was determined to be 7, 7, 9 and 15 mycoplasma cells per microgram of human genomic DNA for M. genus,M. fermentans, M. hominis and M. penetrans, respectively.

The assay was applied to DNA extracted from the PBMCs of individuals suffering from chronic fatigue syndrome (CFS) (n=100) as determined by the Center for Disease Control (CDC) criteria, and compared to healthy individuals (n=100).

The percentage of M. genus infection was found to be 52% in CFS patients and only 15% in healthy individuals. Mycoplasma fermentans, M. hominis andM. penetrans were detected in 32, 9 and 6% of the CFS patients while they were detected in 8, 3 and 2% of the healthy control subjects, respectively.

This assay provides a rapid and cost efficient procedure to screen either cell cultures or clinical samples for the presence of three potentially pathogenic species of mycoplasma with a high level of sensitivity and specificity.

Copyright 1998 Academic Press.

 

Source: Choppa PC, Vojdani A, Tagle C, Andrin R, Magtoto L. Multiplex PCR for the detection of Mycoplasma fermentans, M. hominis and M. penetrans in cell cultures and blood samples of patients with chronic fatigue syndrome. Mol Cell Probes. 1998 Oct;12(5):301-8. http://www.ncbi.nlm.nih.gov/pubmed/9778455

 

Chronic fatigue syndrome: an immunological perspective

Abstract:

OBJECTIVE: The aim of this study is to review research examining an immunological basis for chronic fatigue syndrome (CFS) and to discuss how a disturbance in immunity could produce central nervous system (CNS)-mediated symptoms.

METHOD: Data relevant to the hypothesis that abnormal cytokine release plays a role in the pathogenesis of CFS are reviewed as well as recent evidence relating to potential mechanisms by which immune products may enter the brain and produce a disturbance in CNS processes.

RESULTS: Examinations of cytokine levels in patients with CFS have produced inconclusive results. Recent evidence suggests that abnormal release of cytokines within the CNS may cause neural dysfunction by a variety of complex mechanisms.

CONCLUSION: Neuropsychiatric symptoms in patients with CFS may be more closely related to disordered cytokine production by glial cells within the CNS than to circulating cytokines. This possibility is discussed in the context of unresolved issues in the pathogenesis of CFS.

 

Source: Vollmer-Conna U, Lloyd A, Hickie I, Wakefield D. Chronic fatigue syndrome: an immunological perspective. Aust N Z J Psychiatry. 1998 Aug;32(4):523-7. http://www.ncbi.nlm.nih.gov/pubmed/9711366