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Celiac Sprue: What's Old, What's New<3>
-------------------------------------
Kenneth D. Fine, MD
[Dr. Fine, gastroenterologist, is Medical Director, GI Physiology Lab,
Baylor University Medical Center, in Texas. He is also medical
advisor for the Lone Star Celiac Support Group in Dallas/Fort Worth.
Dr. Fine was in Houston in October to address the Texas Academy of
Family Physicians on Primary Care for the 90's.]
Dr. Fine has been researching celiac disease (CD), malabsorption,
refractory sprue, and microscopic colitis at Baylor University Medical
Center since 1989.
The clinical definition of CD: small intestinal histopathologic
(abnormal under the microscope) lesion, symptoms, or signs due to
malabsorption of fluid, electrolytes, or nutrients, and clinical
improvement following a gluten-free (GF) diet. Newer developments in
diagnosis of CD now include the antigliadin and antiendomysial
antibody blood tests and HLA genetic tests.
Populations thought to be at greatest risk are mostly northern
Europeans and some southern Europeans (England, Ireland, Spain,
Italy). It is more frequent in women, although that situation may
reflect more female patients seeing doctors and being diagnosed, and
recent research is suggesting that the disease may not have any gender
predilection. We have little information on the prevalence of CD in
the Near East, Middle East, and Latin America; it has been thought not
to occur in Africa or the Far East but this may not hold true for
descendants from these lands that emigrated to the USA.
CD: Cause, Symptoms, Signs, and Treatment
-----------------------------------------
There is a genetic predisposition to the disease. There is increased
prevalence in first-degree relatives, approximately 10%, and the
disease is associated with certain HLA genes. The HLA genes are in
charge of the body's immune system. There may be environmental
factors which trigger the disease, which researchers are still trying
to determine.
Common intestinal symptoms include weight loss, flatulence (gas),
diarrhea, constipation, abdominal distention, bloating, and vomiting.
Other symptoms not associated with the gut include weakness,
peripheral neuropathy (numbness or tingling in hands or feet), muscle
spasms, bone pain, night blindness, and cessation of menses. Some
patients do not have any symptoms; in these patients CD was likely
detected by their doctors in a routine examination of nutritional
deficiencies.
Abnormalities that may be detected by doctors include steatorrhea (fat
in the stool), anemia (and a variety of other nutrient deficiencies),
osteopenia, peripheral neuropathy, hyposplenism (decreased function of
the spleen), and decreased calcium, magnesium, zinc, phosphorus,
albumin, cholesterol, and carotene in the blood stream.
Villi serve to increase the surface area of the small intestine. In a
celiac patient, the genes tell your intestinal system to attack
gliadin, and in the process the small intestine becomes damaged. This
causes diarrhea due to interference of normal absorption of fluid,
electrolytes, and nutrients. Under the microscope, villous atrophy of
varying degrees can be seen.
If your doctor suspects CD, what should he do? We hope the first
thing done is to perform a screening panel of celiac antibody blood
tests. There should be an analysis of the stool for fat. A biopsy of
the small intestine is usually performed. If this comes back
positive, then the patient is put on a GF diet.
If patients do not respond to the GF diet after initial diagnosis, Dr.
Fine likes to do a genetic test to see if the patient has the DQ2 or
DQ8 HLA markers. (At least 95% of celiacs have DQ2 or DQ8 HLA
markers, but so do many non-celiacs.) If these genes are not present,
then it is highly likely that the patient does not have CD.
The only treatment for CD is a strict GF diet. The necessary degree
of gluten restriction for patients to remain symptom-free varies.
However, though you may be less sensitive than other celiacs, that
does not mean you're not doing damage to your intestine.
When first diagnosed, celiacs should probably avoid milk sugar
(lactose), because your intestine needs to heal to regain the ability
to break lactose down. Once the intestine heals you will probably be
able to resume dairy products consumption, unless you are one of the
many adults (both celiac and non-celiac) who are lactose-intolerant
anyway.
Folic acid or folate is a vitamin that is necessary for regeneration
of cells. Most celiacs will be deficient in this vitamin. Dr. Fine
recommends at least 1 mg. per day for celiacs, and when newly
diagnosed 2 mg. per day or more may be necessary. [Check with your
own doctor for specific dosage-ed.] If deficiencies in this or other
nutrients (such as iron, calcium, and magnesium) are detected prior to
diagnosis, then supplementation for these nutrients should also be
prescribed.
If the patient does not respond right away on a GF diet, doctors may
prescribe corticosteroids (like prednisone). This seems to happen
more in older people, and probably has do with the fact that CD may
have been present for a long time so that the body needs assistance in
decreasing inflammation. Regeneration of villi occurs quicker in
children, but regrowth and healing should be accomplished after one
year in most celiacs of all ages.
After resolution of symptoms on a GF diet, patients may be tempted to
reintroduce gluten-containing foods to see the response. At first no
symptoms may appear. However, in most if not all patients, symptoms
will reappear after some latency period. We are concerned that if
this is done, symptoms may come back with greater severity and the
process may then become refractory.
Refractory Sprue
----------------
Most patients and doctors do not need to worry about refractory sprue,
because most people do respond to the GF diet. In refractory sprue,
there is no response to a GF diet, or there is a relapse following the
initial response.
You might never respond to a GF diet if you inadvertently continue to
ingest gluten. Unfortunately, this is very common as gluten occurs in
processed foods and is hidden in many different forms. There have
been cases where there was a CD-like syndrome due to ingredients such
as fish proteins or egg proteins, but these are rare. Sometimes
refractory sprue can be explained by co-existent intestinal lymphoma.
Or CD may not be a correct diagnosis; you may have something that
looks like CD but has a different cause and may require a different
treatment, such as Crohn's disease. If your symptoms are not due to
gluten, then of course you will not respond to a GF diet.
Sometimes a refractory sprue condition may be treated with certain
immunosuppressant agents. Immunosuppressants are drugs that suppress
the immune system's response to stimuli. The prognosis of refractory
sprue varies, but is usually poor (unfortunately).
Patients with refractory sprue frequently have microscopic colitis, a
similar immune reaction that occurs in the large intestine. Although
we are not certain what role gluten plays in its cause, microscopic
colitis occurs in at least 5% of celiac patients and 67% of refractory
sprue patients.
Dr. Fine conducted a study at Baylor University Medical Center
looking at the prevalence and causes of chronic diarrhea in treated
celiacs. These are patients that have responded to the diet, but
still have diarrhea. The frequency of diarrhea after diagnosis and
its cause were studied. Of 78 patients entered in the study, 12 had
persistent diarrhea from a variety of causes. For those 12, the
following causes were found:
* Microscopic colitis was the most common cause of persistent diarrhea
following treatment of a GF diet, occurring in 4 out of the 12.
* Carbohydrate malabsorption, either from lactose or fructose,
occurred in 2. (This is easy to treat; just modify the diet to
avoid milk and/or fruit sugars.)
* Irritable bowel syndrome (IBS) occurred in 2 of the 12. In IBS,
diarrhea alternates with constipation. The cause is unknown, but is
not connected to gluten or the absence of gluten in the diet.
However, Dr. Fine believes there are probably patients diagnosed
with IBS that actually have CD.
* Deficiency of pancreatic enzyme production in 2 patients. Even
though the intestine regains its villi and can absorb nutrients, the
pancreas actually has to provide enzymes to digest the food first.
If you don't break down the food first, it can't be absorbed. This
is easily treated by giving pancreatic enzyme supplements.
* Nerve damage caused fecal incontinence in 2 patients. If you have
this condition you must tell your doctor, as it can masquerade
diarrhea when you don't have control. (Patients are often reluctant
to admit to fecal incontinence.)
The Colon and CD
----------------
Baylor University has also done some research into the histology of
the colon in patients with CD. For the most part the colon looks
normal endoscopically and under the microscope. If you do very
sophisticated analysis, you can see increased numbers of lymphocytes
in the tissues, but this is not really colitis. This condition will
occur in about 20% of celiac patients at the time of diagnosis. Over
time, however, it seems that up to 5% of patients develop microscopic
colitis, even those on a GF diet.
Incidentally, a coordinating study is revealing that there does not
seem to be an increase in polyp or colon cancer in celiac patients,
which is comforting. These growths are common in the general
population, but the incidence does not seem to be increased in
celiacs.
Microscopic Colitis
-------------------
Microscopic colitis is a syndrome, meaning a constellation of findings
taken all together. These findings are chronic, watery, non-bloody
diarrhea; a normal colonoscopic appearance; and a certain
histopathology of the colon. The cause is unknown, but research to
learn the cause appears hopeful. It may have something to do with
bacteria, something in the diet, or the body's reaction to itself. It
is an immune system directed inflammatory condition.
Dr. Fine's research team conducted a study using Pepto Bismol(tm)
tablets. 12 patients were treated with 8 chewable tablets per day for
8 weeks. 10 had a resolution of diarrhea, and 9 of them had a
resolution of the colitis under the microscope. There were no
toxicity or side effects. Ironically, 2 patients became constipated.
Some of the patients were also celiacs. Those without CD had no
recurrence of diarrhea when they stopped taking Pepto Bismol(tm).
However, some of the celiacs required retreatment at 3-6 month
intervals.
Associated Disorders
--------------------
Some of the associated disorders that occur with CD (in addition to
microscopic colitis) include pancreatic insufficiency, dermatitis
herpetiformis, type 1 diabetes, hypothyroidism, Sjogren's syndrome
(causing dry mouth and eyes), and potentially other "autoimmune"
syndromes.
Lymphomas
---------
For chronically untreated celiacs there is an increase in carcinomas
of the throat, esophagus, and small intestine, and in lymphomas of the
small intestine. The good news is that if you stay on a strict GF
diet and become well, then according to the studies the expected
survival after the disease is diagnosed is about the same as the
general population.
Follow-up After Diagnosis
-------------------------
Following diagnosis immediately there should be a consultation with an
expert and referral to a celiac support group. Dr. Fine believes
both are important to start effective treatment. In 1-6 months you
might want to have a checkup to be sure things are improving.,
including: measurement of body weight to be sure you are increasing
if there was a loss; a complete blood count if there was anemia
before; and if you are not doing well, celiac antibody tests to check
compliance with the diet. [Other doctors may different follow-up
plans-ed.]
At 1-2 years, Dr. Fine likes to do a bone density test. Dr. Fine
prefers not to do a bone density test at the time of diagnosis because
he knows that going on the diet will improve the results. He wants to
see what your bone density is when it plateaus, not when it is at its
low point.
Dr. Fine feels that every year or two the patient should be asked
about diarrhea and fecal incontinence. Stool studies and gliadin
antibody blood tests should be done if the patient is not doing well.
Baylor University Medical Center has a foundation accepting
tax-deductible donations for Dr. Fine's CD research. Send donations
to Baylor University Medical Center, GI Research, 2nd Floor
Hoblitzelle, 3500 Gaston Ave., Dallas, TX 75246. Their new web page
is at <http://www.bhcs.com/bumc/intestinalresearch/>
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