RNase L levels in peripheral blood mononuclear cells: 37-kilodalton/83-kilodalton isoform ratio is a potential test for chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a disorder characterized by debilitating fatigue associated with immunological abnormalities. The etiology remains unclear. A low-molecular-mass (37 kDa) isoform of RNase L has been described in peripheral blood mononuclear cell (PBMC) extracts, and the ratio of two isoforms of RNase L (37 kDa/83 kDa) has been proposed as a potential biochemical marker of CFS. In a prospective case-control study, we tested whether the RNase L 37-kDa/83-kDa ratio could discriminate a SFC population.

We compared the ratio of RNase L isoforms in PBMCs from 11 patients with CFS (6 women and 5 men; mean age +/- standard deviation, 43.2 +/- 13.8 years) and PBMCs from 14 healthy well-matched volunteers (10 women and 4 men; age, 39.1 +/- 11.6 years). A ratio of RNase L of 0.4 used as a threshold allowed diagnosis of CFS with high sensitivity (91%; 95% confidence interval [CI], 57 to 99%) and specificity (71%; 95% CI, 41 to 90%). The positive and negative prognostic values were 71% (95% CI, 41 to 90%) and 91% (95% CI, 57 to 99%), respectively.

In the absence of acute infection or chronic inflammation, a high RNase L ratio could distinguish CFS patients from healthy volunteers. Additional large studies and follow-up studies are required to confirm the stability of this high ratio of RNase L isoforms in a CFS group.

Comment in: 37-Kilodalton/83-kilodalton RNase L isoform ratio in peripheral blood mononuclear cells: analytical performance and relevance for chronic fatigue syndrome. [Clin Diagn Lab Immunol. 2005]

 

Source: Tiev KP, Demettre E, Ercolano P, Bastide L, Lebleu B, Cabane J. RNase L levels in peripheral blood mononuclear cells: 37-kilodalton/83-kilodalton isoform ratio is a potential test for chronic fatigue syndrome. Clin Diagn Lab Immunol. 2003 Mar;10(2):315-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC150526/ (Full article)

 

Peripheral blood mononuclear cell beta-endorphin concentration is decreased in chronic fatigue syndrome and fibromyalgia but not in depression: preliminary report

Abstract:

OBJECTIVE: The aim of this study was to examine the possible role of the immune system in the pathophysiology of chronic fatigue syndrome and fibromyalgia syndrome and in the differential diagnosis of depression by investigating changes in peripheral blood mononuclear cell levels of beta-endorphin, an endogenous opioid known to be involved in regulation of the immune system function.

DESIGN: Beta-endorphin concentrations were measured by radioimmunoassay in peripheral blood mononuclear cells from healthy controls (n = 8) and patients with chronic fatigue syndrome (n = 17), fibromyalgia syndrome (n = 5), or depression (n = 10).

RESULTS: Beta-endorphin concentrations were significantly lower in patients with chronic fatigue syndrome or fibromyalgia syndrome than in normal subjects and depressed patients (p <0.001 and p <0.01, respectively). They were significantly higher in depressed patients than in controls (p <0.01).

CONCLUSIONS: Evaluation of peripheral blood mononuclear cell beta-endorphin concentrations could represent a diagnostic tool for chronic fatigue syndrome and fibromyalgia and help with differential diagnosis of these syndromes versus depression. The results obtained are also consistent with the hypothesis that the immune system is activated in both chronic fatigue syndrome and fibromyalgia syndrome.

 

Source: Panerai AE, Vecchiet J, Panzeri P, Meroni P, Scarone S, Pizzigallo E, Giamberardino MA, Sacerdote P. Peripheral blood mononuclear cell beta-endorphin concentration is decreased in chronic fatigue syndrome and fibromyalgia but not in depression: preliminary report. Clin J Pain. 2002 Jul-Aug;18(4):270-3. http://www.ncbi.nlm.nih.gov/pubmed/12131069

 

Cytokines and chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) patients show evidence of immune activation, as demonstrated by increased numbers of activated T lymphocytes, including cytotoxic T cells, as well as elevated levels of circulating cytokines. Nevertheless, immune cell function of CFS patients is poor, with low natural killer cell cytotoxicity (NKCC), poor lymphocyte response to mitogens in culture, and frequent immunoglobulin deficiencies, most often IgG1 and IgG3.

Immune dysfunction in CFS, with predominance of so-called T-helper type 2 and proinflammatory cytokines, can be episodic and associated with either cause or effect of the physiological and psychological function derangement and/or activation of latent viruses or other pathogens. The interplay of these factors can account for the perpetuation of disease with remission/exacerbation cycles. A T-helper type 2 predominance has been seen among Gulf War syndrome patients and this feature may also be present in other related disorders, such as multiple chemical sensitivity. Therapeutic intervention aimed at induction of a more favorable cytokine expression pattern and immune status appears promising.

 

Source: Patarca R. Cytokines and chronic fatigue syndrome.  Ann N Y Acad Sci. 2001 Mar;933:185-200. http://www.ncbi.nlm.nih.gov/pubmed/12000020

 

A twin study of the etiology of prolonged fatigue and immune activation

Abstract:

Risk factors to prolonged fatigue syndromes (PFS) are controversial. Pre-morbid and/or current psychiatric disturbance, and/or disturbed cell-mediated immunity (CMI), have been proposed as etiologic factors.

Self-report measures of fatigue and psychologic distress and three in vitro measures of CMI were collected from 124 twin pairs. Crosstwin-crosstrait correlations were estimated for the complete monozygotic (MZ; 79 pairs) and dizygotic (DZ; 45 pairs) twin groups. Multivariate genetic and environmental models were fitted to explore the patterns of covariation between etiologic factors. For fatigue, the MZ correlation was more than double the DZ correlation (0.49 versus 0.16) indicating strong genetic control of familial aggregation.

By contrast, for in vitro immune activation measures MZ and DZ correlations were similar (0.49-0.69 versus 0.42-0.53) indicating the etiologic role of shared environments. As small univariate associations were noted between prolonged fatigue and the in vitro immune measures (r = -0.07 to -0.12), multivariate models were fitted. Relevant etiologic factors included: a common genetic factor accounting for 48% of the variance in fatigue which also accounted for 4%, 6% and 8% reductions in immune activation; specific genetic factors for each of the in vitro immune measures; a shared environment factor influencing the three immune activation measures; and, most interestingly, unique environmental influences which increased fatigue but also increased markers of immune activation.

PFS that are associated with in vitro measures of immune activation are most likely to be the consequence of current environmental rather than genetic factors. Such environmental factors could include physical agents such as infection and/or psychologic stress.

 

Source: Hickie IB, Bansal AS, Kirk KM, Lloyd AR, Martin NG. A twin study of the etiology of prolonged fatigue and immune activation. Twin Res. 2001 Apr;4(2):94-102. http://www.ncbi.nlm.nih.gov/pubmed/11665341

 

Is depression associated with immune activation?

Abstract:

BACKGROUND: Some research immunologists have suggested that major depression amd chronic fatigue syndrome (CFS) are characterized by immune activation. To test this hypothesis, we compared immunological function in patients with major depression and in patients with CFS who developed major depression after the onset of CFS to that of sedentary healthy controls.

METHODS: Subjects completed the Centers for Epidemiological Study-Depression (CES-D) questionnaire and allowed venisection. We performed flow cytometric analysis on 13 groups of white blood cells and used a reverse transcriptase PCR method to assay m-RNA of eight cytokines.

RESULTS: CES-D scores were high in both patient groups and did not differ significantly. We found no evidence for immune activation in either patient group. Instead the data suggested immunological downregulation in depression.

LIMITATIONS: Not all the subjects in the two patient groups were off antidepressants.

CONCLUSIONS: The data indicate that immune activation is not necessary in depression–either alone or with CFS.

 

Source: Natelson BH, Denny T, Zhou XD, LaManca JJ, Ottenweller JE, Tiersky L, DeLuca J, Gause WC. Is depression associated with immune activation? J Affect Disord. 1999 May;53(2):179-84. http://www.ncbi.nlm.nih.gov/pubmed/10360413

 

Immunologic parameters in chronic fatigue syndrome, major depression, and multiple sclerosis

Abstract:

The purpose of this study was to evaluate the immune dysfunction hypothesis of chronic fatigue syndrome (CFS) by comparing immunologic data from patients with CFS with data from patients with other fatiguing illnesses–major depression and multiple sclerosis (MS)–and with data from healthy sedentary controls.

The subjects were 65 healthy sedentary controls, 71 CFS patients (41 with no axis-I diagnosis), 23 patients with mild MS, and 21 patients with major depression. Blood was sampled and assayed for the following: (1) immunologic serologic variables–circulating immune complexes (i.e., Raji cell and C1q binding), immunoglobulins A, E, G, and M, and IgG subclasses; (2) cell surface activation markers–the proportion of CD4+ cells expressing CD45RA+ and CD45RO+ and the proportion of CD8+ cells expressing CD38+, CD11b-, HLA-DR+ and CD28+; and (3) natural killer (NK) total cell count as well as the proportion of lymphocytes expressing NK cell surface markers (i.e., CD3-/CD16+ and CD56+.

Of the 18 variables studied, differences between CFS patients and controls were found only for IgG1 and IgG3. When CFS patients were stratified by the presence or absence of concurrent axis-I disease, it was the group with axis-I disorder that had the lowest IgG1 values-contrary to expectation.

When data from patients with MS and major depression were also evaluated, the subclass deficiency was no longer significant. The one group to show evidence for immune activation (i.e., an elevated proportion of CD4+ cells expressing the CD45RA+ activation marker) was the group with mild MS.

These data support neither immune dysfunction nor immune activation in CFS or in major depression, for the variables studied. The reductions in IgG subclasses may be an epiphenomenon of patient or control subject composition. In contrast, MS, even in the mild and early stages, as in the patients studied here, is associated with immune activation.

 

Source: Natelson BH, LaManca JJ, Denny TN, Vladutiu A, Oleske J, Hill N, Bergen MT, Korn L, Hay J. Immunologic parameters in chronic fatigue syndrome, major depression, and multiple sclerosis. Am J Med. 1998 Sep 28;105(3A):43S-49S. http://www.ncbi.nlm.nih.gov/pubmed/9790481

 

Serum neopterin and somatization in women with chemical intolerance, depressives, and normals

Abstract:

The symptom of intolerance to low levels of environmental chemicals (CI, chemical intolerance) is a feature of several controversial polysymptomatic conditions that overlap symptomatically with depression and somatization, i.e., chronic fatigue syndrome, fibromyalgia, multiple chemical sensitivity, and Persian Gulf syndrome. These syndromes can involve many somatic symptoms consistent with possible inflammation. Immunological or neurogenic triggering might account for such inflammation.

Serum neopterin, which has an inverse relationship with l-tryptophan availability, may offer a marker of inflammation and macrophage/monocyte activation. This study compared middle-aged women with CI (who had high levels of affective distress; n = 14), depressives without CI (n = 10), and normals (n = 11).

Groups did not differ in 4 p.m. resting levels of serum neopterin. However, the CI alone had strong positive correlations between neopterin and all of the scales measuring somatization. These preliminary findings suggest the need for additional research on biological correlates of ‘unexplained’ multiple somatic symptoms in subtypes of apparent somatizing disorders.

 

Source: Bell IR, Patarca R, Baldwin CM, Klimas NG, Schwartz GE, Hardin EE. Serum neopterin and somatization in women with chemical intolerance, depressives, and normals. Neuropsychobiology. 1998;38(1):13-8. http://www.ncbi.nlm.nih.gov/pubmed/9701717

 

A study of the immunology of the chronic fatigue syndrome: correlation of immunologic parameters to health dysfunction

Abstract:

Surface and intracellular immunologic and apoptotic markers and functional lymphocyte assays after stimulation with anti-CD3/anti-CD28 antibodies or phytohemagglutinin (PHA) were studied in 44 patients fulfilling the Oxford criteria for chronic fatigue syndrome (CFS). Results were then correlated to scores for the Short Form-36 health questionnaire (SF-36), which assesses eight aspects of patient’s well-being, and for the general health questionnaire (GHQ), which detects current psychiatric disorder.

Patients had significantly increased mean fluorescence intensity readings of HLA-DR in CD4 and CD8 cells (P < 0.05). Expression of the costimulatory receptor CD28 in CD8 cells was significantly reduced, and the apoptosis repressor ratio of bcl-2/bax in both CD4 and CD8 was increased in patients (P < 0.05).

Patients with increased HLA-DR expression had significantly lower SF-36 total scores, worse body pains, and poorer general health perception and physical functioning scores. Increased spontaneous lymphocyte proliferation was associated with poor general health perception. PHA proliferative responses were lower in patients with poor emotional and mental health scores, and the anti-CD3/anti-CD28 response was low in those with low general health perception scores.

Higher spontaneous proliferation and reduced PHA responses correlated with higher GHQ scores. Similarly, GHQ scores were significantly higher, indicating worse mental health, in those with lower total SF-36 scores and worse general and mental health scores in the SF-36 questionnaire.

Finally, higher expression of the costimulatory molecule CD28 correlated with higher total SF-36 scores, general health perception and social functioning scores, and with lower role limitation due to physical health. The increased expression of class II antigens and the reduced expression of the costimulatory receptor CD28, which is a marker of terminally differentiated cells, lend further support to the concept of immunoactivation of T-lymphocytes in CFS and may be consistent with the notion of a viral etiopathogenesis in the illness.

We report, for the first time, increased expression of the apoptosis repressor protein bcl-2, which may contribute to enhanced survival of activated lymphocytes. Using the SF-36 health assessment questionnaire and the GHQ, we demonstrated changes in different immunological parameters, each of which correlated with particular aspects of disease symptomatology.

 

Source: Hassan IS, Bannister BA, Akbar A, Weir W, Bofill M. A study of the immunology of the chronic fatigue syndrome: correlation of immunologic parameters to health dysfunction. Clin Immunol Immunopathol. 1998 Apr;87(1):60-7. http://www.ncbi.nlm.nih.gov/pubmed/9576011

 

Chronic fatigue syndrome: an update

Abstract:

Among the many patients who seek medical care for the complaint of fatigue, a small number suffer from chronic fatigue syndrome (CFS). CFS is a poorly understood condition characterized by debilitating fatigue and associated symptoms lasting at least six months. Studies indicate that the illness is not simply a manifestation of an underlying psychiatric disorder, but rather is an illness characterized by activation of the immune system, various abnormalities of several hypothalamic-pituitary axes, and reactivation of certain infectious agents.

 

Source: Komaroff AL, Buchwald DS. Chronic fatigue syndrome: an update. Annu Rev Med. 1998;49:1-13. http://www.ncbi.nlm.nih.gov/pubmed/9509246

 

Upregulation of the 2-5A synthetase/RNase L antiviral pathway associated with chronic fatigue syndrome

Abstract:

Levels of 2′,5′-oligoadenylate (2-5A) synthetase, bioactive 2-5A, and RNase L were measured in extracts of peripheral blood mononuclear cells (PBMCs) from 15 individuals with chronic fatigue syndrome (CFS) before and during therapy with the biological response modifier poly(I).poly(C12U) and were compared with levels in healthy controls.

Patients differed significantly from controls in having a lower mean basal level of latent 2-5A synthetase (P < .0001), a higher pretreatment level of bioactive 2-5A (P = .002), and a higher level of pretherapy RNase L activity (P < .0001). PBMC extracts from 10 persons with CFS had a mean basal level of activated 2-5A synthetase higher than the corresponding control value (P = .009). All seven pretherapy PBMC extracts tested were positive for the replication of human herpesvirus 6 (HHV-6).

Therapy with poly(I).poly(C12U) resulted in a significant decrease in HHV-6 activity (P < .01) and in downregulation of the 2-5A synthetase/RNase L pathway in temporal association with clinical and neuropsychological improvement. The upregulated 2-5A pathway in CFS before therapy is consistent with an activated immune state and a role for persistent viral infection in the pathogenesis of CFS. The response to therapy suggests direct or indirect antiviral activity of poly(I).poly(C12U) in this situation.

 

Source: Suhadolnik RJ, Reichenbach NL, Hitzges P, Sobol RW, Peterson DL, Henry B, Ablashi DV, Müller WE, Schröder HC, Carter WA, et al. Upregulation of the 2-5A synthetase/RNase L antiviral pathway associated with chronic fatigue syndrome. Clin Infect Dis. 1994 Jan;18 Suppl 1:S96-104. http://www.ncbi.nlm.nih.gov/pubmed/8148461