Changes in gastrointestinal permeability in celiac disease.

Area of Science:

• Gastroenterology
• Immunology
• Clinical Diagnostics

Background:

• Gastrointestinal permeability is elevated in celiac disease, initially thought to stem from a genetic defect.
• Normalization of permeability tests occurs in patients adhering to a long-term gluten-free diet.
• High permeability is also observed in unaffected relatives and patients with irritable bowel syndrome, showing a tendency to normalize over time.

Purpose of the Study:

• To evaluate the role and diagnostic utility of gastrointestinal permeability tests in celiac disease.
• To assess the correlation between permeability measurements and adherence to a gluten-free diet.
• To determine the sensitivity and specificity of different permeability tests in various celiac disease presentations.

Main Methods:

• Sucrose permeability test for gastroduodenal permeability.
• Lactulose/mannitol ratio for small intestinal permeability.
• In vitro mucosal flux studies.

Main Results:

• Active celiac disease shows elevated gastroduodenal and small intestinal permeability, with high sensitivity but low specificity for the lactulose/mannitol test.
• The lactulose/mannitol test has lower sensitivity (74%) in silent celiac disease without diarrhea.
• Permeability measurements correlate with mucosal atrophy in patients on a gluten-free diet, making it valuable for follow-up.

Conclusions:

• The lactulose/mannitol test is the sole noninvasive functional test essential for active celiac disease diagnosis and dietary follow-up.
• Permeability testing is vital for monitoring treatment efficacy and assessing mucosal healing in celiac patients.
• While sensitive, the low specificity of permeability tests necessitates their use in conjunction with other diagnostic markers.