Following is news of current publications and research efforts underway related
to chronic fatigue
syndrome (CFS)--also called chronic fatigue and immune dysfunction syndrome (CFIDS).
Autoantibody tied to CFS
Japanese researchers have discovered a
new autoantibody that may be linked to a subset of CFS patients with hypersomnia
and cognitive complaints.
More than 13 percent of the 114 CFS patients in the study tested positive for
autoantibodies to a 68/48 kDa protein. In this subset, 80 percent of subjects
complained of hypersomnia, compared to 36 percent in the non-antibody group.
Impaired memory and concentration complaints also were significantly higher in
the subset. No control subjects showed signs of the antibody.
The study's authors say the antibodies may serve as a useful serological
marker for CFS patients with sleep and cognitive difficulties.
Nishikai M et al. Autoantibodies to a 68/48 kDa protein in chronic
fatigue syndrome and primary fibromyalgia: a possible marker for hypersomnia and
cognitive disorders. Rheumatology. 2001; 40(7):806-810.
Depression not cause of cognitive symptoms
patients with chronic fatigue syndrome (CFS) cannot be fully explained by
accompanying depressive symptoms, according to a new study in the journal
Researchers looked at 101 patients, 29 of whom met the modified 1994
international research case definition for CFS. The depression group included 23
non-CFS patients with a history of major depressive disorders. A third group of
24 patients had been diagnosed with clinically definite multiple sclerosis (MS).
There were 25 healthy controls.
The subjects were given a battery of neuro-psychological tests. The scores
were grouped into five cognitive domains: attention, memory, language, executive
function and spatial ability.
In general, the depression group showed the highest levels of cognitive
impairment compared to controls, followed by MS patients, then CFS patients.
While CFS scores were generally worse than controls, the difference did not
reach statistical significance.
After adjusting scores for CFS patients based on self-reported depressive
symptoms, the authors write that the presence of depression in CFS patients
"cannot solely account for the cognitive differences among the patient
Daly E et al. Neuropsychological function in patients with chronic
fatigue syndrome, multiple sclerosis and depression. Applied
Neuropsychology. 2001; 8(1):12-22.
RNAse L variant active
A novel protein in some CFS patients'
antiviral pathways is far more active than previously realized, according to a
study in the June issue of the Journal of Biological Chemistry.
The protein, 37 kDa RNase L, has been identified in a subset of CFS patients,
but not in fibromyalgia or depression patients. Presence of the 37 kDa RNase L
has previously been correlated with the level of clinical disability in CFS
patients. The new study showed that it is structurally similar to the normal 80
kDa RNase L and can be detected with the same azido photoaffinity probe, even
though it is less than half the size of the 80 kDa form.
However, the 37 kDa form is at least three times faster at hydrolyzing RNA
than the 80 kDa form. The authors say they will continue to study the structure
of the protein and work to determine the role it plays in CFS.
Shetzline SE, Suhadolnik RE. Characterization of a 2',5'-Oligoadenylate
(2-5A)-dependent 37 kDa RNase L. J Biol Chem. 2001;
Pre-CFS patients visit doctors often
People who develop CFS consult
their physicians more frequently than other patients in the years prior to their
illness, according to new British research.
The study looked at records from 14 general medical practices in Devon,
England. Researchers tracked the histories of 49 CFS patients and 49 matched
controls. The researchers found that CFS patients visited their doctors nearly
twice as often as the controls during the 15-year period prior to diagnosis.
CFS patients were 8.5 times more likely to visit a doctor with complaints of
upper respiratory tract infections than were controls. They also were seven
times more likely to mention lethargy and 3.8 times more likely to complain of
The authors offer several explanations for the increased office visits -
including the possibility that the patients already had CFS and were
Hamilton WT et al. Frequency of attendance in general practice and
symptoms before development of chronic fatigue syndrome: a case-control study.
Brit J of Gen Prac. 2001; 51:553-558.
New method finds immune differences
In the past, linear methods
have proven unreliable for detecting immunological abnormalities in CFS patients
versus control groups. In a recent paper, scientists describe using neural
network classifiers to detect immune differences that were previously
Neural networks are a type of nonlinear classification system that has been
shown to provide optimal identification of factors in situations where the data
is multilayered and multiple comparisons are being made.
Researchers looked at immunological data for 103 CFS patients and 87 healthy
but sedentary controls. Multilayer neural networks showed an over 16%
improvement in identifying immune differences than traditional linear methods. A
sensitivity analysis of the network found differences between groups that are
consistent with the hypothesis that CFS symptoms are a consequence of immune
Hanson SJ et al. Detection of immunologically significant factors for
chronic fatigue syndrome using neural-network classifiers. Clin Diagnostic
Lab Immunol. 2001; 658-662.