Heretofore regarded as an uncommon disease, celiac sprue is increasingly being recognized as an underdiagnosed condition affecting an estimated one of every 120 to 300 persons in Europe and North America. Farrell and Kelly reviewed the essentials of diagnosis and management of patients with celiac sprue, highlighting serologic tests now available for investigating suspected cases of the disease.

Classically, celiac sprue has been diagnosed in a young infant who fails to thrive and has chronic diarrhea, but it is now apparent that the condition affects persons of all ages, with about 20 percent of cases occurring in persons older than 60 years. In about one half of adults with celiac sprue, presenting symptoms include diarrhea, flatulence, and weight loss. The other 50 percent, however, have more subtle manifestations such as anemia (either iron-deficiency anemia from intestinal blood loss or macrocytic anemia from folate malabsorption), a coagulopathy caused by vitamin K deficiency, or hypocalcemia and osteoporosis from malabsorption of vitamin D.

Celiac sprue is an autoimmune disease of the small intestine resulting from ingestion of gluten (found in wheat, barley, and rye grains) in sensitive persons. An abnormal T-cell response leads to production of antibodies against various intestinal targets. Serologic testing is now integral to establishing the diagnosis of celiac sprue. IgA anti-endomysial and anti-gliadin antibodies, as well as antibodies against tissue transgluta-minase, have reasonable sensitivity and specificity for diagnosing celiac sprue. Endoscopic biopsy of the distal duodenum is still the gold standard for diagnosis, showing marked changes in the intestinal mucosa with loss of villi and crypt hyperplasia.

When celiac sprue is apparent by serologic and histologic findings, a trial gluten-free diet is indicated (see the accompanying table). The majority of patients improve rapidly in the first few weeks of the diet, although complete reversion to a normal intestinal mucosa on repeat biopsy is usually seen only in children.

Failure to improve while on a gluten-free diet should increase suspicion for other causes of small bowel enteropathy or may indicate noncompliance with the strict diet, which for most patients is difficult to follow. Patients with severe, refractory celiac sprue are at increased risk of developing intestinal T-cell lymphoma. Steroids and other immunosuppressants may be used when symptoms remain severe despite a gluten-free diet.