BACKGROUND: Results of readily available clinical laboratory
tests in patients with chronic fatigue syndrome were compared
with results in healthy control subjects.
consisted of all 579 patients who met either the Centers for
Disease Control and Prevention, Atlanta, Ga, British, or
Australian case definition for chronic fatigue syndrome. They
were from chronic fatigue clinics in Boston, Mass, and
Seattle, Wash. Control subjects consisted of 147 blood donors
who denied chronic fatigue. Outcome measures were the results
of 18 clinical laboratory tests.
RESULTS: Age- and
sex-adjusted odds ratios of abnormal results, comparing cases
with control subjects, were as follows: circulating immune
complexes, 26.5 (95% confidence interval [CI] 3.4-206) [in 35%
vs 2%], atypical lymphocytosis, 11.4 (95% CI, 1.4-94) [in 8%
vs 1%]; elevated immunoglobulin G, 8.5 (95% CI, 2.0-37) [in
25% vs 4%]; elevated alkaline phosphatase, 4.2 (95% CI,
1.6-11) [in 18% vs 5%]; elevated total cholesterol, 2.1 (95%
CI, 1.2-3.4); and elevated lactic dehydrogenase, 0.30 (95% CI,
0.16-0.56). Also, antinuclear antibodies were detected
[>=1:40] in 15% of cases vs 0% in the control subjects. The
results of these tests were generally comparable for the cases
from Seattle and Boston. Although these tests served to
discriminate the population of patients from healthy control
subjects, at the individual level they were not as useful.
CONCLUSIONS: Patients with chronic fatigue syndrome who
were located in two geographically distant areas had
abnormalities in the results of several readily available
clinical laboratory tests compared with healthy control
subjects. The immunologic abnormalities are in accord with a
growing body of evidence suggesting chronic, low-level
activation of the immune system in chronic fatigue syndrome.
While each of these laboratory findings supports the diagnosis
of chronic fatigue syndrome, each lacks sufficient sensitivity
to be a diagnostic test. Furthermore, the specificity of these
findings relative to other organic and psychiatric conditions
that can produce fatigue remains to be established.
Bates DW, Buchwald D, Lee J, Kith P, Doolittle T, Rutherford C,
Churchill WH, Schur PH, Wener M, Wybenga D, et al