Saludos a todos, espero que os vaya bien.
The Public Health Alert is a really good source of information -
here's an article explaining the immune complement factors C3a and C4a and CD57
in easy to understand terms, and written by Ginger Savely, a nurse practitioner
who has published research with Dr Stricker.
BW,
Denise
http://www.publichealthalert.org/Articles/gingersavely/C3a%20and%20C4a.htm
When a Complement is not a Compliment:
The Role of C3a and C4a Complement Proteins in Chronic Lyme Disease
by Ginger Savely, DNP
Readers of this publication are well aware of the controversies surrounding the
diagnosis and treatment of Lyme disease. When the disease is missed in its
early, easier-to-treat stage, it goes on to become a complex, multi-system
disease that eludes diagnosis, mimics many other diseases, and requires
aggressive, long-term treatment.
Because the testing methods for Lyme and other tick-borne diseases are
insensitive, many true cases of infection go undetected. Even when the diseases
are detected, the unreliability of the testing makes it difficult to track
treatment progress and test for cure.
Work by Drs Stricker and Winger identified CD57 positive natural killer cells as
immune markers that tend to be low in chronic Lyme patients and increase with
clinical improvement.
An earlier article that I wrote for this publication explained how the
measurement of CD57+NK cells in the blood has helped Lyme-literate health care
providers in making the diagnosis of Lyme disease when tests are inconclusive.
It has also provided a convenient marker to assist in following treatment
progress and determining treatment end.
Although the CD57 marker has been a helpful tool, it has not been without its
problems. We don't yet understand what confounding variables can skew the
results. Some very sick patients start out with normal or above-normal CD57
levels. Other patients' levels stay low and never increase with treatment,
despite the fact that they are symptom-free and otherwise seem completely cured.
There may be large day to day variation in the CD57 level as I observed in a
study looking at twice daily blood draws over 3 days for both Lyme patients and
well patients. The level can increase or decrease as much as 50% within the same
day. So the CD57 level can be a useful marker for some patients but it is not
always reliable and consistent.
Enter C3a and C4a, the new kids on the block in the world of Lyme diagnosis and
treatment. The "C" in C3a and C4a stands for complement. Complement proteins
work with antibodies to destroy pathogens. They activate immunity through
control of inflammation, phagocytosis (ingestion of pathogens by white blood
cells) and cell death by lysis (breaking of the cell membrane). There are about
30 of these complement proteins that circulate in the bloodstream making up
complement "cascades", so called because activation of one protein initiates
activation of the next, etc.
Dr. Ritchie Shoemaker and his colleagues published a study in 2008 reporting
elevated C3a and C4a levels in acute Lyme disease. Many patients who contract
Lyme disease do not develop the diagnostic "bull's eye rash", and Lyme tests are
frequently negative shortly following a tick bite when prompt diagnosis is
crucial for effective treatment. Shoemaker et al. suggested that elevated C3a
and C4a levels can serve as early markers in the diagnosis of acute Lyme
disease.
Because CD57+ NK cell levels are not always reliable markers for chronic Lyme,
there is an ongoing search for new biomarkers to aid in the diagnosis of
chronic, disseminated Lyme disease and to follow treatment progress. Dr.
Stricker and I recently published a study in the Scandinavian Journal of
Immunology comparing C3a and C4a levels of chronic Lyme patients to those of
healthy controls, AIDS patients and patients with systemic lupus.
The C3a complement protein level was normal in the AIDS patients, the healthy
patients and the chronic Lyme patients. So, although C3a was shown to be
elevated in a cohort of early, acute Lyme disease patients, it appears to be
normal in chronic Lyme patients.
In our study, only the systemic lupus patients had elevated levels of C3a. Other
published studies have associated elevated C3a with autoimmunity as well.
Therefore, the C3a may prove to be a useful marker in differentiating ongoing
symptoms due to an autoimmune process versus an ongoing infectious process.
For purposes of our C3a/C4a study, Dr. Stricker divided the chronic Lyme
patients into two groups: 1) those with primarily musculoskeletal symptoms (MSK)
and 2) those with neurological symptoms severe enough to warrant treatment with
intravenous antibiotics.
Interestingly, C4a levels were significantly elevated in the MSK group, but only
slightly (and not statistically significantly) elevated in the neurologic group.
C4a levels were also elevated in the AIDS and systemic lupus groups, but not in
the healthy controls. In Lyme patients with elevated C4a, the levels decreased
in those who responded well to antibiotic treatment.
Those patients who did not improve on antibiotics (more often than not, the
severe neurological group) had no statistically significant reduction in their
C4a levels.
Keep in mind that almost all chronic Lyme patients have some degree of
neurological involvement. The neurological Lyme patients in the study who did
not have elevated levels of C4a were those with severe cognitive dysfunction as
evidenced by abnormal blood flow to areas of the brain noted on their SPECT
brain scans. Examples of these patients are those who presented with symptoms
mimicking Alzheimer's disease, multiple sclerosis, Parkinson's disease, or
Autism Spectrum Disorder.
Amyotrophic lateral sclerosis (ALS) patients do not have cognitive deficits and,
in fact, Lyme patients with this type of severe neurological presentation did
have elevated C4a levels.
The normal range for the C4a is zero to 2830. In my chronically ill Lyme
patients I have seen C4a levels as high as about 26,000. However, most of my
patients start with a pre-treatment level between 6000 and 12,000. In the two
years that I have been using the C4a test to track treatment progress, reduction
in C4a levels has consistently correlated with clinical improvement.
Patients often ask if there are other medical conditions that may lower or raise
the C3a and/or C4a. Both of these complement products may be increased in normal
pregnancy and in certain types of vasculitis (an inflammatory condition that
destroys blood vessels).
C4a levels are elevated in adult insulin dependent diabetes. Those who suspect
that chronic fatigue syndrome (CFS) may actually be misdiagnosed Lyme disease
may not be surprised to hear that C4a is also elevated in CFS patients. In fact
the C4a is probably elevated in all sorts of infections, and therefore is not
specific to Lyme.
If you would like your health care provider to order your C3a and C4a levels, it
is extremely important that the tests be performed only at the National Jewish
Medical and Research Center Laboratory in Denver. LabCorp has a contract with
National Jewish and therefore your health care provider can order LabCorp tests
# 840702 (C3a) and # 857334 (C4a). LabCorp uses two different send-out labs for
the test and it is important to indicate that samples should be routed to
National Jewish for most accurate results. Ask your health care provider to
write on the requisition slip in large letters: "ACCESSIONING: C3a & C4a MUST BE
ROUTED TO NATIONAL JEWISH". To find the LabCorp drawing station nearest you, go
to www.labcorp.com and enter your city or zip code in the space provided in the
lower left of the home page.
If your health care provider writes the ICD-9 (diagnostic) code of 279.3 (Immune
dysregulation) on your LabCorp requisition slip, insurance will more than likely
cover the C3a and C4a tests. However, if your insurance does not cover the
tests, the prices are not prohibitive. Each of the tests cost $ 75.60 (valid as
of 3-25-09).
Because most lab technicians are unfamiliar with the C3a and C4a tests, it is in
your best interest to go to the LabCorp drawing station knowing exactly how your
blood should be handled. This way you will be assured that your sample will
arrive at the lab satisfactory for testing. The blood needs to be drawn into an
EDTA tube ("lavender top") and immediately spun and separated. The plasma should
be frozen right away and sent frozen to National Jewish.
The C4a is not as specific to chronic Lyme as the CD57+ level because it may be
elevated in many types of infection, including other tick-borne diseases.
However, in patients with known tick-borne infections, the C4a complement
protein test can provide a useful way to determine initial degree of infection,
to follow treatment progress and to aid in deciding upon treatment end. For more
information about the C3a and C4a, please see the suggested readings below:
Shoemaker RC, Giclas PC, Crowder C, House D, Glovsky MM.Shoemaker, R. C.,
Giglas, P.C., Crowder, C., House, D. Glovsky, M.M. Complement split products C3a
and C4a are early markers of acute lyme disease in tick bite patients in the
United States. International Archives of Allergy and Immunology, 146(3),
255-261.
Stricker, R. B., Savely, V.R., Motanya, N.C. & Giglas, B.C. (2009). Complement
split products C3a and C4a in chronic Lyme disease. Scandinavian Journal of
Immunology, 69(1), 64-69.
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