Celiac disease is an autoimmune disorder triggered by gluten consumption in genetically predisposed individuals. It affects about 1% of the population, causing symptoms like diarrhea, bloating, fatigue, and, if untreated, complications such as malnutrition or osteoporosis. Diagnosis typically involves serologic tests (e.g., anti-tissue transglutaminase antibodies) and confirmation via small intestine biopsy, though non-invasive approaches are being explored.

HLA testing identifies genetic variants associated with celiac disease, specifically HLA-DQ2 and HLA-DQ8. These variants are present in ~95% of celiac patients but are not diagnostic alone, as ~30-40% of the general population also carry them. Testing is useful in specific scenarios:

• Ruling out celiac disease: A negative HLA-DQ2/DQ8 result makes celiac disease highly unlikely (negative predictive value ~99%).
• Clarifying ambiguous cases: For patients with equivocal serology or biopsy results, or those already on a gluten-free diet.
• Screening high-risk groups: First-degree relatives of celiac patients or those with related conditions like type 1 diabetes.

HLA testing involves a blood or saliva sample to analyze DNA for DQ2/DQ8 alleles. It’s a one-time test since genetics don’t change. However, a positive result doesn’t confirm celiac disease, and routine use isn’t recommended due to low specificity.

Limitations include cost, variable insurance coverage, and the fact that many with DQ2/DQ8 never develop celiac disease. It’s most valuable when used selectively, guided by clinical context. If considering testing, consult a gastroenterologist or immunologist for interpretation.

If you have specific questions about testing or need guidance on next steps, let me know!

Disclaimer: owerl is not a doctor; please consult one.