Celiac disease and selected long-term health issues.

Celiac disease is a genetically-based and immunologically-mediated systemic disorder, affecting primarily the small intestine in adults. About 0.5-1% of most populations studied are affected, with up to 2% in Finland. In families, specifically first-degree relatives, up to 20% may have the disease. Despite increased awareness among physicians and the public, celiac disease is still markedly under-diagnosed at all ages, including the elderly. Although serological screening is now widely used, celiac disease remains a biopsy-defined disorder, and a critical element to the correct diagnosis is documentation of a response to a gluten-free diet (since it is a gluten-sensitive disease). Sometimes, after the diagnosis has been established with a treatment response, changes re-appear and seem resistant to a gluten-free diet. Usually, poor or limited diet compliance, possibly from an unrecognized gluten source is responsible. In others, another superimposed cause, such as an infectious agent, could be important. Finally, another associated disease causing similar clinical and biopsy features or, alternatively, a complicating disorder may develop, such as a lymphoma. Some with biopsy features suggestive of celiac disease may not respond to a gluten-free diet. These may not have celiac disease at all, but instead, a sprue-like intestinal disease, or so-called unclassified sprue.