NIH conference. Chronic fatigue syndrome research. Definition and medical outcome assessment

Abstract:

A workshop was held 18 to 19 March 1991 at the National Institutes of Health to address critical issues in research concerning the chronic fatigue syndrome (CFS). Case definition, confounding diagnoses, and medical outcome assessment by laboratory and other means were considered from the perspectives of key medical specialties involved in CFS research.

It was recommended that published Centers for Disease Control (CDC) case-definition criteria be modified to exclude fewer patients from analysis because of a history of psychiatric disorder. Specific recommendations were made concerning the inclusion or exclusion of other major confounding diagnoses, and a standard panel of laboratory tests was specified for initial patient evaluation.

The workshop emphasized the importance of recognizing other conditions that could explain the patient’s symptoms and that may be treatable. It was viewed as essential for the investigator to screen for psychiatric disorder using a combination of self-report instruments followed by at least one structured interview to identify patients who should be excluded from studies or considered as a separate subgroup in data analysis.

Because CFS is not a homogeneous abnormality and because there is no single pathogenic mechanism, research progress may depend upon delineation of these and other patient subgroups for separate data analysis. Despite preliminary data, no physical finding or laboratory test was deemed confirmatory of the diagnosis of CFS.

For assessment of clinical status, investigators must rely on the use of standardized instruments for patient self-reporting of fatigue, mood disturbance, functional status, sleep disorder, global well-being, and pain. Further research is needed to develop better instruments for quantifying these domains in patients with CFS.

 

Source: Schluederberg A, Straus SE, Peterson P, Blumenthal S, Komaroff AL, Spring SB, Landay A, Buchwald D. NIH conference. Chronic fatigue syndrome research. Definition and medical outcome assessment. Ann Intern Med. 1992 Aug 15;117(4):325-31. http://www.ncbi.nlm.nih.gov/pubmed/1322076

 

Symptoms and signs of chronic fatigue syndrome

Abstract:

This review summarizes the symptoms and signs seen in patients with chronic fatigue syndrome (CFS). It is based on the authors’ experience with two cohorts of approximately 510 patients with chronic debilitating fatigue and on the reported experience of other investigators with similar patients.

The most characteristic symptoms of CFS are the sudden onset of an infectious-type illness, the subsequent chronic and debilitating fatigue, and postexertional malaise; many patients also have recurrent fevers, pharyngitis, adenopathy, myalgias, sleep disorders, and cognitive impairment.

 

Source: Komaroff AL, Buchwald D. Symptoms and signs of chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S8-11. http://www.ncbi.nlm.nih.gov/pubmed/2020806

 

Review of laboratory findings for patients with chronic fatigue syndrome

Abstract:

Various abnormalities revealed by laboratory studies have been reported in adults with chronic fatigue syndrome. Those most consistently reported include depressed natural killer cell function and reduced numbers of natural killer cells; low levels of circulating immune complexes; low levels of several autoantibodies, particularly antinuclear antibodies and antithyroid antibodies; altered levels of immunoglobulins; abnormalities in number and function of lymphocytes; and modestly elevated levels of two Epstein-Barr virus-related antibodies, immunoglobulin G to viral capsid antigen and to early antigen.

 

Source: Buchwald D, Komaroff AL. Review of laboratory findings for patients with chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S12-8. http://www.ncbi.nlm.nih.gov/pubmed/1902321

 

High frequency of fibromyalgia in patients with chronic fatigue seen in a primary care practice

Abstract:

We administered a standardized history questionnaire and performed a tender point examination on 27 patients with debilitating fatigue of at least 6 months duration, seen in a primary care practice, as well as on 20 patients with fibromyalgia.

Sixteen of the 27 patients with chronic fatigue met the full criteria for the working case definition of chronic fatigue syndrome (CFS). Eight patients with chronic fatigue denied having any current persistent, diffuse musculoskeletal pain, and their tender point scores were similar to those in 10 normal control subjects. In contrast, 19 patients with chronic fatigue (70%) had persistent, diffuse musculoskeletal pain.

The results of their tender point examinations were similar to those of the patients with fibromyalgia. Thus, the majority of these patients with debilitating chronic fatigue, including those who met criteria for CFS, met the historical and tender point diagnostic criteria for fibromyalgia. The presence of current musculoskeletal pain will identify those CFS patients who have fibromyalgia.

 

Source: Goldenberg DL, Simms RW, Geiger A, Komaroff AL. High frequency of fibromyalgia in patients with chronic fatigue seen in a primary care practice. Arthritis Rheum. 1990 Mar;33(3):381-7. http://www.ncbi.nlm.nih.gov/pubmed/2317224

 

The chronic fatigue syndrome: definition, current studies and lessons for fibromyalgia research

Abstract:

Chronic fatigue syndrome (CFS) is characterized by chronic, debilitating fatigue lasting greater than 6 months. Frequent chronic and recurrent findings include fever, pharyngitis, myalgias, adenopathy, arthralgias, difficulties in cognition and disorders of mood. In the majority of patients, the illness starts suddenly with an acute, “flu-like” illness.

The following laboratory abnormalities are seen with some frequency, although none are seen in all patients: lymphocytosis, atypical lymphocytosis, monocytosis, elevation of hepatocellular enzymes, low levels of antinuclear antibodies, varying levels of antithyroid antibodies, partial hypergammaglobulinemia, elevated CD4:CD8 ratio, decreased cytolytic activity of natural killer cells, and low levels of immune complexes. Clinical and serologic studies suggest an association of CFS with all of the human herpesviruses, particularly Epstein-Barr virus (EBV) and the recently discovered human B lymphotropic virus (HBLV) or human herpesvirus 6; neither EBV nor HBLV has yet been shown to play a causal role in the illness.

Preliminary evidence suggests that many of these features of CFS also are seen in patients with fibromyalgia.

 

Source: Komaroff AL, Goldenberg D. The chronic fatigue syndrome: definition, current studies and lessons for fibromyalgia research. J Rheumatol Suppl. 1989 Nov;19:23-7. http://www.ncbi.nlm.nih.gov/pubmed/2691680

 

Chronic fatigue syndrome: a working case definition

Abstract:

The chronic Epstein-Barr virus syndrome is a poorly defined symptom complex characterized primarily by chronic or recurrent debilitating fatigue and various combinations of other symptoms, including sore throat, lymph node pain and tenderness, headache, myalgia, and arthralgias.

Although the syndrome has received recent attention, and has been diagnosed in many patients, the chronic Epstein-Barr virus syndrome has not been defined consistently. Despite the name of the syndrome, both the diagnostic value of Epstein-Barr virus serologic tests and the proposed causal relationship between Epstein-Barr virus infection and patients who have been diagnosed with the chronic Epstein-Barr virus syndrome remain doubtful.

We propose a new name for the chronic Epstein-Barr virus syndrome–the chronic fatigue syndrome–that more accurately describes this symptom complex as a syndrome of unknown cause characterized primarily by chronic fatigue. We also present a working definition for the chronic fatigue syndrome designed to improve the comparability and reproducibility of clinical research and epidemiologic studies, and to provide a rational basis for evaluating patients who have chronic fatigue of undetermined cause.

 

Source: Holmes GP, Kaplan JE, Gantz NM, Komaroff AL, Schonberger LB, Straus SE, Jones JF, Dubois RE, Cunningham-Rundles C, Pahwa S, et al. Chronic fatigue syndrome: a working case definition. Ann Intern Med. 1988 Mar;108(3):387-9. http://www.ncbi.nlm.nih.gov/pubmed/2829679

 

“Chronic Epstein-Barr virus infection” syndrome and polymyalgia rheumatica

Abstract:

Twenty-three patients with polymyalgia rheumatica (PMR) followed in an academic rheumatology practice frequently reported symptoms commonly found in the recently described “chronic fatigue syndrome” or “chronic Epstein-Barr infection syndrome.” These symptoms persisted for months after treatment had reduced the severity of the myalgias and lowered the sedimentation rate: periodically disabling fatigue (33%), recurrent pharyngitis (30%), sleep disorder (65%) and arthralgias (70%). However, antibody titers to Epstein-Barr virus in the patients with PMR were not significantly different from those in age and sex matched control subjects.

 

Source: Buchwald D, Sullivan JL, Leddy S, Komaroff AL. “Chronic Epstein-Barr virus infection” syndrome and polymyalgia rheumatica. J Rheumatol. 1988 Mar;15(3):479-82. http://www.ncbi.nlm.nih.gov/pubmed/2837573

 

Chronic fatigue syndromes: relationship to chronic viral infections

Abstract :

Chronic fatigue syndrome (CFS) is a newly-recognized clinical entity characterized by chronic, debilitating fatigue lasting longer than six months. Common associated findings are chronic and recurrent fever, pharyngitis, myalgias, adenopathy, arthralgias, difficulties in cognition and disorders of mood. In the majority of patients, the illness starts suddenly with an acute, ‘flu-like’ illness.

The following abnormalities are seen with some frequency although none are seen in all patients: lymphocytosis, atypical lymphocytosis, monocytosis, elevation of hepatocellular enzymes, low levels of antinuclear antibodies, low levels of immune complexes.

Clinical and serologic studies suggest an association of CFS with all of the human herpesviruses, particularly Epstein-Barr virus (EBV) and the recently-discovered human B-lymphotropic virus (HBLV) or human herpesvirus-6; neither EBV nor HBLV has yet been shown to play a causal role in the illness.

 

Source: Komaroff AL. Chronic fatigue syndromes: relationship to chronic viral infections. J Virol Methods. 1988 Sep;21(1-4):3-10. http://www.ncbi.nlm.nih.gov/pubmed/2846619

 

Frequency of ‘chronic active Epstein-Barr virus infection’ in a general medical practice

Abstract:

Twenty-one percent of 500 unselected patients, aged 17 to 50 years, seeking primary care for any reason were found to be suffering from a chronic fatigue syndrome consistent with “chronic active Epstein-Barr virus (EBV) infection,” They had been experiencing “severe” fatigue, usually cyclic, for a median of 16 months (range, six to 458 months), associated with sore throat, myalgias, or headaches; 45% of the patients were periodically bedridden; and 25% to 73% reported recurrent cervical adenopathy, paresthesias, arthralgias, and difficulty in concentrating or sleeping.

The patients had no recognized chronic “physical” illness and were not receiving psychiatric care. While antibody titers to several EBV-specific antigens were higher in patients than in age- and sex-matched controls subjects, the differences generally were not statistically significant.

A chronic fatigue syndrome consistent with the chronic active EBV infection syndrome was prevalent in our primary care practice. However, our data offer no evidence that EBV is causally related to the syndrome. Indeed, we feel that among unselected patients seen in a general medical practice currently available EBV serologic test results must be interpreted with great caution.

 

Source: Buchwald D, Sullivan JL, Komaroff AL. Frequency of ‘chronic active Epstein-Barr virus infection’ in a general medical practice. JAMA. 1987 May 1;257(17):2303-7. http://www.ncbi.nlm.nih.gov/pubmed/3033338

 

Phenotypic and functional deficiency of natural killer cells in patients with chronic fatigue syndrome

Abstract:

Natural killer (NK)3 cells are large granular lymphocytes that appear to play a significant role in the host’s defense against viral infection. We performed an extensive phenotypic and functional characterization of NK cells on 41 patients with the chronic fatigue syndrome (CFS), or “chronic active Epstein-Barr virus infection” syndrome, and on 23 age- and sex-matched asymptomatic control subjects in an attempt to further characterize this illness.

These studies demonstrated that a majority of patients with CFS have low numbers of NKH1+T3- lymphocytes, a population that represents the great majority of NK cells in normal individuals. CFS patients had normal numbers of NKH1+T3+ lymphocytes, a population that represents a relatively small fraction of NK cells in normal individuals.

When tested for cytotoxicity against a variety of different target cells, patients with CFS consistently demonstrated low levels of killing. After activation of cytolytic activity with recombinant interleukin 2, patients were able to display increased killing against K562 but most patients remained unable to lyse Epstein-Barr virus-infected B cell targets. Additional cytotoxicity experiments were carried out utilizing anti-T3 monoclonal antibody to block killing by NKH1+T3+ cells.

These experiments indicated that the NK cell that appears to be responsible for much of the functional activity remaining in patients with CFS belongs to the NKH1+T3+ subset, which under normal circumstances represents only approximately 20% of the NK cell population.

 

Source: Caligiuri M, Murray C, Buchwald D, Levine H, Cheney P, Peterson D, Komaroff AL, Ritz J. Phenotypic and functional deficiency of natural killer cells in patients with chronic fatigue syndrome. J Immunol. 1987 Nov 15;139(10):3306-13. http://www.ncbi.nlm.nih.gov/pubmed/2824604