Food Intolerance Panel™

Gluten Intolerance

Gluten intolerance is more prevalent than was previously understood. Historically the diagnosis relied on biopsy of the small intestine. Patients with less severe or vague symptoms were in most cases excluded as candidates for biopsy. In addition, a normal biopsy does not exclude the disease; inflammation may be patchy, or tissue may show some degree of response that falls short of villous atrophy and other diagnostic criteria. With the advent of biochemical markers for gluten intolerance, several studies have proven the presence of specific antibody-verified, gluten-free diet-validated gluten intolerance in a large sector of the society (12–18 % depending on ethnicity). A step forward in redefining the incidence of the disease was the introduction of broader definitions of the disease entity. Newly added subtypes allow inclusion of variants previously not included among gluten- intolerance patients.

Silent gluten intolerance: A completely asymptomatic form usually associated with gross damage to small intestinal mucosa and positive biochemical markers (anti-gliadin and other antibodies).

Latent gluten intolerance: May be vaguely or mildly symptomatic and is associated with grossly normal intestinal lining that shows signs of low-grade intestinal inflammation. It is associated with increased intra-epithelial lymphocyte counts, and biochemical markers are usually positive.

Milk intolerance (sometimes termed cow milk sensitive enteropathy): Cow’s milk-induced small intestinal mucosal damage that is reversed by a cow’s milk-free diet and recurs on challenge. It is an abnormal physiologic response to casein in genetically predisposed individuals. The reaction includes metabolic, toxic and immunopathologic (inflammatory) responses to casein.

Milk intolerance is caused by casein and other milk antigens or proteins. Casein triggers a toxic reaction on contact with intestinal cells. This contact triggers an inflammatory cascade resulting in damage to the mucosal barrier. The inflammatory cells produce mediators that signal local lymphocytes to produce antibodies against casein. The first and main antibody response on the gut mucosal lining is secretory IgA.

Damage to small intestinal lining and clinical symptoms vary widely. In severe cases, the problem is apparent in early age (< 3 years of age). In milder cases, the patient may be completely asymptomatic, yet suffering an ongoing inflammatory insult to the small intestine. The mucosal barrier damage is in the form of mild to moderate villous atrophy (villous shortening) in a patchy manner.

Lactose Intolerance

Lactose intolerance is a common condition caused by deficiency in the intestinal brush-border enzyme lactase. Its effects are largely dose-dependent. In many cases, a transitional or reversible lactose intolerance is observed. This is commonly experienced in patients with food intolerances where the sloughing of the mucosa leads to a decreased availability of the lactase enzyme. The sloughing results in loss of the disaccharidase-containing mature enterocytes, leading to a reduction in lactase small intestinal activity. Usually when patients implement a strict avoidance program of the offending food, their lactose intolerance vanishes.

Egg Intolerance

It is defined as egg white-induced, small intestinal mucosa damage that is reversed by an egg-free diet and recurs on challenge. It is an abnormal physiologic response to ovalbumin in genetically predisposed individuals. The reaction includes metabolic, toxic and immunopathologic (inflammatory) responses to ovalbumin. Egg intolerance caused by ovalbumin occurs with hen and most other bird eggs. Ovalbumin triggers a toxic reaction on contact with intestinal cells. This contact triggers an inflammatory cascade resulting in damage to the mucosal barrier. The inflammatory cells produce mediators that signal local lymphocytes to produce antibodies against casein. The initial and major antibody subclass to increase in the gut mucosal lining is secretory IgA.

Soy Intolerance (termed soy protein-sensitive enteropathy)

It is defined as soy protein-induced small intestinal mucosa damage that is reversed by a soy-free diet and recurs on challenge. It is an abnormal response to soy proteins in genetically predisposed individuals. The reaction includes metabolic, toxic and immunopathologic (inflammatory) responses to soy. Damage to small intestinal lining and clinical symptoms vary widely. In severe cases, the problem is apparent in early age (< 3 years of age). In milder cases the patient may be completely asymptomatic, yet suffering an ongoing inflammatory insult to the small intestine as shown by secretory IgA release.

For more information about tests in this panel, please refer to the links at the left.