Celiac Sprue

Mrs M. was excited. Finally, somebody found out what was wrong with her! A mother of 3 children she had been feeling more and more tired in the last 18 months. She found herself taking naps in the afternoon when her youngest daughter was asleep. It was all she could do to take care of her family. She had seen her family doctor several times over the past year and was told that she was anemic. Twice she was given a prescription for iron pills and told to get plenty of rest. She did both for months and saw no improvement. She still felt very tired and run down. It was very frustrating. She was beginning to think her problems were all in her head. Finally, she was sent to see a specialist. After some blood tests and several simple scope tests, the doctor announced that her problem was celiac sprue and that treatment was available to help her. She had never even heard of this condition, but was happy to hear that she was not "crazy" and that a special diet could cure her. With a special diet and iron replacement, her anemia was cured and she now feels well.

The Small Intestine
In the middle of your abdomen lies the twenty foot long small intestine. It is here that the final process of digestion and nutrient absorption takes place from the two gallons of food, liquid, and digestive secretions you process each day.The small intestine is divided into three sections: the first part called the duodenum, the middle portion, referred to as the jejunum, and the last part called the ileum. The entire small intestine is lined with intricate sets of muscles which are never at complete rest. One group produces a swaying motion that churns together food and digestive juices. Another set of muscles produces a wavelike action; the waves push the contents along a few inches, then die out. These muscular contractions cause a ripple-like movement that carries the contents down the small intestine - somewhat like a conveyor belt. To maximize absorption, the food molecules must come in contact with a large number of specialized intestinal cells. To accomplish this, the walls of your intestines are covered with microscopic hairlike projections called villi, and even smaller microvilli. Each square inch of intestine contains about 10 billion microvilli. This increases the surface area for food absorption dramatically. In fact, if your intestinal interior were smooth, it would present only about 6 square feet of absorptive surface. Instead, because of these microvilli, it presents almost 4000 square feet - about the same surface as two tennis courts! Microvilli contain special cells which enable absorption of nutrients into your bloodstream. It takes the small intestine about four hours to process a meal. Once all the "good stuff" is removed, your gut passes the indigestible watery gruel that is left to the last five feet of your digestive tract, the colon.

What is celiac sprue?

Celiac sprue is basically a food allergy to a specific dietary protein called gluten - which is found in three grains: wheat, barley, and rye. (The active component of gluten that causes this allergic reaction is a protein called gliadin.) When an individual with sprue eats a food containing gluten, such as a slice of bread, an reaction occurs within the wall of the small intestine. Much like rejecting a transplanted organ, the immune system mounts an all-out attack against gluten - and on any villi that have absorbed it. The villi become inflamed, eventually shriveling up, flattening out or even disappearing. Without functioning villi, the small intestine can't do its job of absorbing nutrients from the diet. Thus, even though an individual is eating normally, nutrients are not properly absorbed and exit the body with bowel movements, a condition call malabsorption. This damage can affect absorption of minerals such as iron. This explains why Mrs. M's anemia did not respond to iron pills.

Accounts of this disorder date over 2000 years, but the association with gluten was not discovered until World War II. A Dutch pediatrician noted that children with this disorder improved during the war related food shortages, only to relapse when cereal supplies were restored. Other common names for this disorder are nontropical sprue, idiopathic sprue, celiac disease, gluten-sensitive enteropathy, and gluten-induced enteropathy.

What causes sprue?
What causes one individual to suddenly become allergic to gluten is unknown. However, there is definitely a genetic predisposition. Most individuals with this disorder are residents of Western Europe and places where Europeans emigrated, such as North America. In the past, it was felt to be a rare disorder affecting about 1 in 3000 individuals. With the advent of new more accurate blood tests, it has been learned that approximately 1 in 200 Americans are affected, most of which are undiagnosed. It is somewhat more common in those of Irish descent. Sprue is rare in those with a pure African, Chinese, Japanese, and Caribbean background. Sprue can develop at any age. However, most individuals are either diagnosed as children about the age of four or much later in the third to fifth decade of life. About 20% of cases occur in patients over the age of 60. Sprue is not contagious, but because of the genetic basis, approximately 10% of first degree relatives (parents, siblings and children) are similarly affected.

What are the symptoms?
In children, diarrhea, weight loss, and growth failure are common. However, most adults don't present with classic symptoms of diarrhea and weight loss. Over 50% of adults have no diarrhea. Abdominal discomfort and bloating are common, but non-specific complaints. Some patients note diarrhea at night and increased flatulence (rectal gas). Generalized tiredness is common. These symptoms are vague and may be misinterpreted as irritable bowel syndrome. Patients may present with signs of vitamin malabsorption such as osteoporosis, bone fractures, defects in dental enamel, infertility or miscarriages, and impaired blood clotting. Recurrent sores in the mouth (apthous stomatitis) may be the only symptom in some patients.

How is sprue diagnosed?
We have three tools to diagnose sprue. The first diagnostic tool is to suspect the problem in the first place. As mentioned above, most adults present with vague and non-specific complaints. The diagnosis of sprue is often delayed due to the vague and diverse nature of the symptoms. A survey of 1,600 sprue patients done by New York's Columbia-Presbyterian Hospital found that on average they took 11 years to be diagnosed.

One of the most common presentations in adults is unexplained iron deficiency anemia. Usually, this type of anemia is caused by loss of blood due to conditions such as heavy menstrual bleeding, pregnancy, peptic ulcer disease or, on occasion, slow bleeding from a tumor of the digestive tract. In this country, most cases of iron deficiency anemia in men are due to chronic blood loss from the digestive tract. In the case of sprue, however, iron deficiency is not due to the loss of blood, but rather poor iron absorption in the damaged small intestine. When iron deficiency anemia is present and there is no sign of blood loss, sprue should be suspected.

When suspected, highly sensitive and specific blood tests are now available to screen for celiac sprue. The blood tests can be used to make the diagnosis and help monitor response to treatment. These blood tests do not require fasting. They are usually sent out to special laboratories and the results may take a week or more to return. Three blood tests are currently available:

• IgA tissue transglutaminase (tTG)
  
• IgA antigliadin antibody
  
• IgA antiendomysial antibody
  

The most commonly used initial screening test is the IgA tissue tranglutaminase, or tTG. The accuracy of these blood tests is over 95%. Falsely positive readings are rare. However, about 2 to 10% of patients with celiac sprue may have an overall deficiency of the general IgA antibody class. In this case, these IgA based blood tests would miss the diagnosis. However, if this is suspected, a less commonly used IgG antigliadin antibody blood test is also available.

If malabsorption is suspected, other more general blood tests are also often performed. These may include tests of liver and kidney function as well as blood tests for anemia (hemoglobin), iron, B12, folate, blood clotting (protime), calcium, and protein levels (albumin) in the blood. If abnormal, these will often be periodically repeated to assess response to treatment.

The treatment for this disorder is a major change in diet. A gluten-free diet is quite inconvenient and more expensive than a regular diet and may limit patients socially, especially younger individuals. Before making this lifelong commitment, it is important to be sure that the diagnosis is correct. Blood antibody tests are very accurate, but not 100% accurate. The diagnosis is usually confirmed by microscopic examination of a biopsy of the mucosa (inner lining) of the small intestine. Today, this is most often accomplished by performing an endoscopic "scope" examination called a gastroscopy. Done under conscious sedation, this painless test allows the doctor to take several small samples of the small intestinal mucosa for laboratory analysis.

As mentioned above, the normal intestinal mucosa is not smooth. Rather, it has a "fuzzy" inner surface due to millions of small villi. (See Illustration) These serve to increase the overall surface area of the small intestine to maximize absorption of food and nutrients. In a case of sprue, the reaction to gluten destroys the villi. Under the microscope, the mucosa is flat and inflamed - a condition called villous atrophy. With adherence to a strict gluten free diet, the villi should grow back and normal intestinal appearance is restored. Often, a repeat biopsy is performed after three to six months of treatment as another way to assess compliance with the diet and response to treatment.

In addition to the tests above, barium x-rays of the small intestine and CT scans are often performed to evaluate patients with unexplained abdominal pain, or when response to a gluten-free diet is less than expected. Often, the doctor will ask an adult with sprue to have a bone density test which measures calcium in the bones. A low value could mean bone loss (osteoporosis) and a higher than normal risk of fractures.

How about treatment?
There is no prescription to restore tolerance to gluten. The only way to stop the damage is not to eat foods containing gluten - wheat, barley, rye. Oats can be contaminated with wheat grains. It is advised that they be avoided initially and slowly added to the diet after a few months of treatment. At that point up to 2 oz of oats from a reliable source can be consumed daily. Patients are advised to use only rice, corn, maize, buckwheat, potato, soybean, or tapioca flours. In reality, complete elimination of gluten is very difficult to achieve. Wheat flour is often used as a thickener in processed and convenience foods. Avoiding foods with gluten requires a high level of patient education and motivation, reading of all labels, and a high index of suspicion. Patients must also not drink all beers, lagers, ales, and stouts. Wine liqueurs, most ciders, and spirits including whiskey and brandy are permitted.

Since many patients with active sprue are lactose (milk sugar) intolerant, avoidance of mild products may be helpful initially, especially if diarrhea and bloating are the presenting complaints. A few weeks after treatment has begun, lactose-containing products may be added back to the diet.

Most sprue patients are encouraged to take a daily multivitamin and mineral supplement as well as extra calcium in their diet.

Can sprue be cured?
No. With continued gluten avoidance, the small intestine lining can regenerate and normal absorptive function will be restored. Symptoms can begin to improve within weeks of beginning treatment. Within several months, the villi in the small intestine begin to grow back and the blood tests revert to normal. However, there is no cure. Gluten allergy is a lifelong ailment. If a patient "falls off the wagon" and eats a slice of wheat bread, the small intestinal lining is damaged and the whole process begins again. Thus all patients with celiac sprue are advised lifelong adherence to a strict gluten-free diet.

Associated conditions
For reasons unknown, several other disorders are more common in patients with sprue. A gluten-sensitive skin rash (Dermatitis herpetiformis) is sometimes seen in adults with celiac disease. This rash appears as painful, itchy, raised red blotches on the elbows, knees and buttocks. This skin rash is uncommon in children. The skin lesions often respond to gluten withdrawl or a medication called Dapsone. Other conditions such as insulin dependent diabetes and thyroid disorders may be associated with sprue.

What happens if you don't follow the diet?
Of course, without treatment malabsorption of nutrients will continue. This often leads to malnutrition, anemia and fatigue. Diarrhea and weight loss may occur. Calcium malabsorption will eventually lead to premature bone loss and osteoporosis. The most feared complication of sprue is a cancer of the small intestine called Non-Hodgkin's lymphoma. The risk of this disorder is approximately three times above normal, but can be reduced by strict gluten avoidance.

How about follow up?
As with any chronic illness, it is important to follow your doctor's advice and keep scheduled appointments. Periodic bloods tests should be done to assess compliance and response to treatment. However, once the condition has stabilized, these appointments need not be frequent. Each case is different and the doctor will decide when a return visit is needed.

Where to go for more information
Basic information should come from your doctor, but the specifics of sticking to a gluten-free diet are best learned with the help of a registered dietician. This may take several sessions and may or may not be covered by health insurance. Either way, this is time and money well spent. Printed materials such as the Gluten-Free Gourmet series of books by Bette Hagman and Gluten-Free Diet -A Comprehensive Resource Guide by Shelley Case are available from Amazon.com

Many patients also benefit by joining a celiac sprue support group. This is a great way to learn from the experiences of others with sprue. This could be through live meetings, but these days, is most often done over the internet. The internet is a great place to learn about gluten-free products and recipes. Just be sure to stick with reputable sites. Some common sources of information include:

• Pittsburgh Celiac Sprue Support Group (www.pittsburghceliac.org)
  
• Gluten Intolerance Group (www.gluten.net)
  
• Celiac Sprue Association (www.csaceliacs.org)
  
• Celiac Disease Foundation (www.celiac.org)
  
• Canadian Celiac Association (www.celiac.ca)
  
• Ener-G Foods (www.ener-g.com)
  
• Glutino (www.glutino.com)
  

Summary
Celiac sprue occurs when genetically predisposed individuals have an inappropriate allergic response to ingested gluten. With repeated exposure, the small intestinal lining becomes severely damaged and malabsorption of nutrients can occur. Classic symptoms of weight loss and diarrhea are rare in adults and many cases go undiagnosed. A common clinical presentation in adults is unexplained iron deficiency anemia. When suspected, simple blood tests are available to screen for this disease. Microscopic examination of a small intestinal biopsy is the gold standard for diagnosis. There is no cure, but lifelong total avoidance of gluten (wheat, barley, rye) allows the small intestinal lining to heal itself and restores normal absorptive function. The diet is difficult to maintain, but strict compliance results in healing of the small intestine, and reduces the risk of serious complications such as cancer of the small intestine. The diet must be continued for life. At present, there is no cure.

Copyright: Robert D. Fusco, MD