2005a). These are rare intestinal malignancies with a high mortality rate. In addition, the relative risk for developing non-Hodgkin’s lymphomas, intestinal or extraintestinal, is three fold greater than in the general population (Catassi et al., 2002). These cancers contribute to nearly two thirds of deaths due to celiac disease and are a major reason for the nearly two-fold increase in overall mortality of adult patients with celiac disease compared to the general population (Corrao et al., 2001).
Currently, individuals with clinical manifestations, or “symptomatic” celiac disease, are believed to represent a small portion of the total affected population (Mäki and Collin, 1997). A larger number of individuals are believed to have “silent” celiac disease, characterized by positive serology and intestinal mucosal abnormalities in the absence of symptoms or nutritional deficiencies. Mäki and Collin (1997) also suggested that there is an even larger population with “latent” celiac disease, individuals who are positive for serological markers or genetic susceptibility to disease and are entirely asymptomatic. It is generally accepted that individuals with silent or latent disease, although asymptomatic, have the capability to manifest aberrant immune responses following exposure to dietary glutens and are, therefore, at increased risk for both acute and long- term complications of celiac disease (Fasano, 2003; Schuppan, 2000). However, the long-term benefit of strict gluten avoidance for these individuals is unproven (Green and Jabri, 2003).
D. Prevalence Until recently, celiac disease was considered to be a rare disorder in the U.S., with an estimated prevalence rate of 1:5,000 (Talley, 1994). However, a large epidemiological study screened more than 13,000 people in 23 states and estimated a prevalence rate of 1:133 within the general U.S. population (Fasano et al., 2003). The National Institutes of Health Consensus Development Conference Statement on Celiac Disease currently estimates that 3 million Americans, a little less than 1 percent of the population, may have celiac disease (NIH, 2004). Celiac disease occurs widely among North American and European populations, where wheat is a staple food, but is infrequent among native descendents of China and Japan and those with an African-Caribbean background, where wheat is not as widely consumed (Farrell and Kelly, 2002).
Precise prevalence data for celiac disease are not available. This disease is often misdiagnosed as another gastrointestinal malabsorptive disorder (e.g., irritable bowel syndrome) due to similarities in their symptoms (Sanders et al., 2001). Due to the existence of silent or latent cases, it is assumed that the incidence of celiac disease is underreported (Mäki and Collin, 1997). These forms of celiac disease may go undetected in individuals for years before they develop symptoms causing them to seek medical attention (Green and Jabri, 2003). Mäki and Collin (1997) postulated that there are many more currently healthy individuals who are genetically predisposed to developing celiac disease in future years than there are individuals who are now affected by celiac disease. Only recently has the medical community become more aware of the need to screen for celiac disease when patients experience health problems that may be associated with the disease or when patients have family members, especially first- and second-degree relatives, who have celiac disease (NIH, 2004).
Revised Threshold Report Page 36 of 108