Celiac Disease Introduction

Celiac disease (CD) is an immune-mediated disorder, the only one with a well-established origin, resulting from a permanent gluten intolerance, which primarily involves the gastrointestinal tract. It is characterized by the presence of chronic inflammation of the small bowel’s mucosa and submucosa, and is clinically characterized by the presence of diverse systemic manifestations.

It may start at any age, both during childhood and adolescence, and is also relatively common in adulthood. It is being increasingly diagnosed even in elderly patients (up to 20% of patients are older than 60 years, at the time of diagnosis)[1-3].

The causal agent, gluten, is well established; a mixture of proteins present exclusively in cereals –mainly wheat, barley, rye and oats- but not corn. It affects only predisposed individuals, whose most susceptible genetic features are related to human leukocytes antigens from class two (HLA-􁶘), predominantly HLA-DQ2 (90%), while much less frequency HLA-DQ8 (5%-10%). However, these genetic markers are a necessary, but not a sufficient condition, since a significant frequency of celiac disease patients (5%-10%) are DQ2 and DQ8-negative.

This means that other, still not well-established, genotypes may exist that probably correspond to the class one HLA system (HLA-􁶗), including MICA, MICB and others[4]. A strong genetic susceptibility is present with about 75% concordance rate, among monozygotic twins. Certain populations have an increased prevalence of CD. For instance, the first-degree relatives of individuals with biopsy-proven CD, have a prevalence between 4%-12% of those suffering from this disease. Second-degree relatives also appear to have an increased prevalence.

Patients with type 1 diabetes mellitus (IDDM) have a prevalence of celiac disease ranging to 3%-8%. In Down´s syndrome, the presence of celiac disease is found between 5%-12%. Also, celiac disease is associated with Turner’s and William’s syndromes, IgA defi ciency and several autoimmune disorders[5-7]. Most affected individuals show sustained clinical remission when they are put strictly on a gluten-free diet (GFD), which must be maintained indefi nitely due to this illness’ genetic background.