Laboratorijski testi za SKU
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Pripravil sem nek prispevek o testih za SKU. Moram opozoriti, da nisem zdravnik, sem le bolnik s SKU, ki se je poglobil v te teste. Informacije sem dobil s spleta.
1. Najbolj praktičen dokument se mi zdi dokument zdravstvene zavarovalnice iz ZDA, ki se ga dobi na naslovu http://www.ssa.gov/OP_Home/rulings/di/01/SSR99-02-di-01.html in sicer tisti del, ki opisuje katere teste oni upoštevajo:
Examples of medical signs that establish the existence of a medically determinable impairment
For purposes of Social Security disability evaluation, one or more of the following medical signs clinically documented over a period of at least 6 consecutive months establishes the existence of a medically determinable impairment for individuals with CFS:
Palpably swollen or tender lymph nodes on physical examination;
Nonexudative pharyngitis;
Persistent, reproducible muscle tenderness on repeated examinations, including the presence of positive tender points;[3] or,
Any other medical signs that are consistent with medically accepted clinical practice and are consistent with the other evidence in the case record.
Examples of laboratory findings that establish the existence of a medically determinable impairment
At this time, there are no specific laboratory findings that are widely accepted as being associated with CFS. However, the absence of a definitive test does not preclude reliance upon certain laboratory findings to establish the existence of a medically determinable impairment in persons with CFS. Therefore, the following laboratory findings establish the existence of a medically determinable impairment in individuals with CFS:[4]
An elevated antibody titer to Epstein-Barr virus (EBV) capsid antigen equal to or greater than 1:5120, or early antigen equal to or greater than 1:640;
An abnormal magnetic resonance imaging (MRI) brain scan;
Neurally mediated hypotension as shown by tilt table testing or another clinically accepted form of testing; or,
Any other laboratory findings that are consistent with medically accepted clinical practice and are consistent with the other evidence in the case record; for example, an abnormal exercise stress test or abnormal sleep studies, appropriately evaluated and consistent with the other evidence in the case record.
Mental findings that establish the existence of a medically determinable impairment
Some individuals with CFS report ongoing problems with short-term memory, information processing, visual-spatial difficulties, comprehension, concentration, speech, word-finding, calculation, and other symptoms suggesting persistent neurocognitive impairment. When ongoing deficits in these areas have been documented by mental status examination or psychological testing, such findings constitute medical signs or (in the case of psychological testing) laboratory findings that establish the presence of a medically determinable impairment.
Individuals with CFS may also exhibit medical signs, such as anxiety or depression, indicative of the existence of a mental disorder. When such medical signs are present and appropriately documented, the existence of a medically determinable impairment is established.
2.Test na RnazoL, ki ga izvaja podjetje R.E.D. Laboratories iz Belgije. Spletni naslov je http://www.redlabs.com/en/index.html in tu je vse razloženo: katere teste delajo, kakšno je ozadje – znanstvene raziskave teh testov in kako se te teste naroči.
3. Leta 2001 je v Nevadi, ZDA potekala konferenca “Nevada Chronic Fatigue Syndrome Consensus Conference” , ki se je posebej ukvarjala s testi za SKU. Rezultati so vidni na spletnem naslovu http://www.cfids-cab.org/cfs-inform/CFS.case.def/levine.etal01.txt
Date sent: Fri, 26 Oct 2001
MEETING REPORT: Nevada Chronic Fatigue Syndrome Consensus Conference
J of Chronic Fatigue Syndrome, Vol. 9 (1/2) 2001, pp. 53-62
Paul H. Levine, MD; Nancy Klimas, MD; Roseanne Armitage, PhD;
Robert Fredericks, MD; Julian Stewart, MD, PhD; William Torch, MD;
Stanley Schwartz, MD; Robert Suhadolnik, PhD; Nancy L. Reichenbach; Lea
Rhodes
The authors are the members of the Nevada Consensus Panel.
Address correspondence to: Paul H. Levine, MD, Department of Epidemiology
and Biostatistics, The George Washington University School of Public
Health and Health Services, Ross Hall 120, 2300 Eye Street NW,
Washington, DC 20037.
The Nevada Consensus Panel was sponsored by the Nevada CFS Association
and the Pioneer Foundation, non-profit organizations committed to
advancing the methodologies used by clinicians to better diagnose,
manage, treat, and rehabilitate patients with CFS.
_______________
Chronic fatigue syndrome (CFS), a debilitating disorder of unknown
etiology, has been the subject of a growing body of literature as
information accumulates on the epidemiology, pathogenesis, and disease
markers. For the practicing physician and patient, however, there are
major obstacles to distinguishing well-documented management techniques
that are reliable and applicable to most patients. The challenge for the
physician is whether to rely upon reportedly successful techniques that
have not been confirmed in the literature or which may only be useful in
a subset of patients that have not been well characterized.
In order to begin the process of developing a manual based on
peer-reviewed literature, a consensus panel was conducted March 16-18,
2000 to address the question: “Which of the research tools and techniques
currently under evaluation are now clinically useful in the management of
patients with CFS?”
The consensus panel consisted of the following members: Nancy Klimas, MD,
and Paul H. Levine, MD, co-chairs; Roseanne Armitage, PhD, Robert
Fredericks, MD, Lea Rhodes, Julian Stewart, MD, PhD, William Torch, MD,
Stanley Schwartz, MD, and Robert Suhadolnik, PhD, and Nancy L.
Reichenbach was executive secretary.
It was not feasible over the two-day session to discuss every CFS-related
symptom in the same detail. Consequently, particular attention was
devoted to those symptoms which appeared to have the most concordant
information leading to conclusions that can be based on the most
consistent data in the peer-reviewed literature. Neuropsychiatric
problems and pain management were not discussed since they were to he the
subject of conferences planned by The CFIDS Association of America and
future meetings of the Nevada group. Rehabilitation was discussed by a
separate concurrent panel, and a number of recommendations immediately
applicable to clinical practice were reviewed. These will be published in
a separate document.
At the outset, the panel noted that one of the major problems in
providing generalized guidelines for clinician management of CFS is the
heterogeneity of the disorder. A number of studies suggest that the 1994
CDC-sponsored revision of the original 1988 case definition, while
broadening the criteria for inclusion of patients into the CFS umbrella,
increased the heterogeneity. It was strongly suggested by the panel that
subtypes be defined using factor analysis, as has been used in the
subgrouping of Gulf War Syndrome (1).
In spite of the problems created by the current case definition,
recommendations were made when appropriate according to criteria adapted
from earlier consensus panels that have undertaken the evaluation of data
in the literature (Table I ). The emphasis of this particular consensus
panel was on laboratory evaluation and the management of sleep disorders,
orthostatic hypotension and endocrine abnormalities.
LABORATORY EVALUATION
Until recently, the role of the laboratory has been considered to be
restricted solely to excluding other disorders that could cause chronic
fatigue. A ruling by the Social Security Administration in June 1999
allowed immune system abnormalities, abnormal Epstein-Barr virus
antibody, and other laboratory tests to support the presence of a
medically determinable condition in patients seeking disability.
It should be emphasized that CFS may be severe and disabling without any
significant physical findings or laboratory abnormalities. A number of
virologic and immunologic abnormalities may be found in CFS patients, but
none are consistent and, therefore, no single test at the present time
can be considered diagnostic for CFS.
Part of the problem results from the heterogeneity of CFS and, as noted
above, it has become readily apparent that subgroups need to be
identified. The identification of useful subgroups remains in question,
although reports suggest that classification by the nature of onset
(acute vs. gradual) and symptom complex (such as infectious, i.e., sore
throat, fever, Iymphadenopathy, vs. non-infectious) would be useful.
One laboratory test that the panel believed had the most promise was the
RNase L test. The overactive response of the antiviral defense pathway in
people with CFS has been well documented (2,3). These laboratory markers
have been utilized in clinical trials (4,5) and include increased
activity of RNase L and the presence of a low molecular weight (LMW) form
of RNase L that is more active than the naturally occurring form.
Several thousand CFS patients have been tested (using PBMC) for the LMW
RNase L, and the results are among those pointing to the important
decrease in specificity with the 1994 case definition: Eighty percent of
patients meeting the 1988 case definition were positive in one study vs.
60 percent of those meeting the 1994 case definition (K. DeMeirlier,
personal communication).
The presence of the LMW RNase L is a quantitative measure; it correlates
well with severity of CFS symptoms and with low NK cell function. It is
consistent with a state of chronic immune activation, but has not been
found in rheumatoid arthritis, lupus erythematosus, HIV infection,
fibromyalgia, or depression (K. DeMeirlier, personal communication).
In some cases of multiple sclerosis, the LMW RNase L is evident (D.
Peterson, personal communications).
Regarding virologic and immunologic markers, the literature has been
confusing and extensive discussion led to the following recommendations:
I. Epstein-Barr virus serology does not provide valuable information for
the physician and is not recommended (although as noted above, elevated
antibody titers do support the presence of a medically determinable
illness in the Social Security evaluation).
2. No evidence currently exists that anti-viral therapy has a beneficial
effect. Treatment for mycoplasma, an unproven etiologic agent, should not
be given until the results of a large study of mycoplasma treatment in
Gulf War Syndrome is completed.
3. While HHV-6 may play a role in exacerbating CFS and chronic
Epstein-Barr virus infection may occur, although rarely, an infectious
disease expert should be consulted before treatment is initiated on the
basis of viral assays.
4. In addition to RNase L, other measures of immune activation, such as
natural killer cell function and T-cell activation (CD2CD26, CD8DR cell
markers) may play a role in supporting the diagnosis of CFS. As with all
use of biological testing, however, it is critical that the laboratories
used for the above tests should have proven records and stringent quality
standards.
SLEEP DISORDERS
Sleep abnormalities in CFS are widely recognized, but often are not well
characterized. Fragmented sleep (periods of wakefulness throughout the
sleep period) and lack of deep stage sleep are very common in CFS
patients. True insomnia (inability to fall asleep) is uncommon, although
patients may have delayed sleep onset because of a disrupted circadian
rhythm.
Non-restorative sleep with multiple awakenings and no deep slow wave
sleep is characteristic of CFS. The absence of these essential components
of sleep is important for immune function, serotonin, and hormonal
balance.
The sleep pattern characteristic of CFS is very different from that
experienced by individuals with depression or fibromyalgia. Assessment of
sleep abnormalities in CFS is essential because treatment implications
are different for CFS without a concurrent sleep disorder.
The panel recommended that educational programs be developed for
physicians to explain the biological necessity for sleep in CFS. A
detailed history and structured sleep interviews are most valuable for
physicians to use in assessing the sleep abnormalities in CFS.
Standardized and validated test instruments (such as the Pittsburgh Sleep
Quality Index) are useful in identifying primary sleep disturbances
without the need for expensive sleep lab studies. A sleep laboratory
study at an accredited sleep disorder center is indicated only if a
primary sleep disorder is evident on the sleep interview.
Body motion sensors, such as Actigraphs, can also be very useful.
Behavioral management can be very effective in dealing with sleep
disorders in CFS, including a regular daily sleep/wake cycle, hot baths
before sleep, and short naps. A hot bath 90 minutes before sleep (not at
bedtime) is a useful tool; declining body temperature is a strong sleep
inducer.
Standard neurological assessment of CFS is very expensive. It utilizes
two insensitive tools in this population (MRI and standard EEG), which
can miss even severe cases of encephalitis-although both tools can be
useful in ruling out other illnesses. More sensitive research tools are
available, such as quantitative EEG that demonstrate abnormalities not
present in MRI scans.
Regarding the pharmacologic treatment of sleep disorders, some
medications commonly used in CFS treatment, including Klonopin, Flexeril
and selective serotonin reuptake inhibitors or SSRIs (most notably
fluoxetine Prozac) may actually worsen sleep fragmentation. Tricyclic
antidepressants and behavioral management as noted above are helpful
sleep treatments in CFS patients.
ORTHOSTATIC INTOLERANCE
Orthostatic intolerance, or the inability to maintain adequate cerebral
blood flow while standing upright, is another well-described abnormality
in CFS although it is not seen with the same frequency as sleep
disorders. Circulatory abnormalities have been well described in patients
with CFS (6-9), and important information has also been obtained from
studies of patients with other disorders sharing the same type of
orthostatic disability seen in CFS patients (10).
The term neurally-mediated hypotension, which can be readily applied to
vasovagal faint, cannot be consistently applied to chronic orthostatic
intolerance (COI) in which hypotension does not always occur. Several
forms of orthostatic intolerance are seen in patients with CFS and
include:
1. Chronic orthostatic intolerance, which includes the defining symptoms
of lightheadness in all patients with a high incidence of altered vision
(blurring, ‘white outs,’ ‘black-outs’ ), fatigue, nausea, palpitations,
headache, tremulousness, difficulty breathing or swallowing, sweating,
pallor, and other vasomotor symptoms;
2. Vasovagal faint, which is associated with loss of conciousness,
nausea, dizziness, heat, heavy breathing and sweatiness associated with
an abrupt decrease in both blood pressure and heart rate.
Thus COI, the form seen in CFS patients is most important to treat. COI
is characterized by tachycardia, whereas vasovagal faint and neurally
mediated hypotension are associated with bradycardia.
COI-POTS (postural orthostatic tachycardia syndrome) is often associated
with an unusual amount of pooling in the dependent extremities and is
associated with cyanosis. This pooling can be documented by measuring leg
circumference before and after standing 30 minutes.
Evaluation of COI should begin with a careful history and physical
examination should include resting heart rate and orthostatic heart rate.
A tilt table test is generally not required but is indicated if the
patient has a strong history for orthostatic intolerance
(lightheadedness, fainting, pallor when upright) or has evidence for
upright tachycardia (> 30 beats/min).
Referral should also be made if the patient has upright orthostatic
symptoms using a 5-10 minute period of standing after being supine with
blood pressure and heart rate taken once per minute. It is also important
to note that tilt table patterns in children are not the same as in
adults.
Regarding treatment for COI, fludrocortisone has been shown to have no
significantly greater effect than placebo (11) but it may be useful in
some patients. Current approaches to treatment include conservative
management such as the use of support hose and avoiding standing for long
periods of time.
ENDOCRINE DYSFUNCTION
The literature on HPA axis dysfunction in CFS reveals low plasma and
urinary cortisol, elevated basal evening corticotropin, enhanced adrenal
sensitivity to corticotropin with a reduced maximal response, and normal
CSF corticotropin releasing hormone (CRH) levels (12). Rather than
suggest a specific work-up to document a CFS-related endocrine
abnormality, the panel suggested that the appropriate endocrine work-up
in CFS patients is to exclude other illnesses, i.e., hypothyroidism (by
CBC and TSH) and Addison’s disease (fasting cortisol).
Among the reasons for not considering a CFS-specific endocrine work-up is
the failure of therapeutic intervention with cortisol to show improvement
that reached statistical significance (13). Therefore, particularly with
the inherent danger of prolonged treatment, steroid treatment (14) cannot
be recommended. Similarly, a trial with fludrocortisone (11) in neurally
mediated hypotension and a Phase I trial of growth hormone ( 15) did not
show significant improvement.
COMMENT
A number of important issues emerged during the panel discussion that
deserve mention as possibilities for application in the near future.
Definitive statements could not be made, however, since the field
currently lacks one of the important characteristics that have yielded
such significant advances in the field of cancer treatment – multicenter
longitudinal trials.
For multicenter longitudinal trial in CFS, unlike cancer, it is
appropriate to monitor natural history and clinical markers in addition
to intervention trials with medications currently in use. An emphasis on
identifying subgroups in these studies is important since preliminary
studies suggest, for example, that CFS patients with the LMW RNase L are
more likely to respond to Ampligen (4, K. DeMeirlier, personal
communication).
Če pa koga še kaj zanima, pa vem še za nekaj dokumentov. Drugače pa je najboljša spletna stran za SKU http://www.cfids-cab.org/cfs-inform/
Če tam klikneš pod CFS def. je lepo opisan sindrom kronične utrujenosti in sicer kaj je to, kakšni so kriteriji za SKU, kakšne bodo bodoče definicije, kateri testi obstajajo za SKU, kako je SKU klasificirana v Mednarodni klasifikaciji bolezni itd.
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Matej
