What does an elevated Immunoglobulin A (IgA) level indicate in a celiac disease test?

Elevated Total IgA in Celiac Disease Testing

What This Means

An elevated total IgA level in the context of celiac disease testing confirms that your IgA-based antibody tests (like tissue transglutaminase IgA or endomysial antibody IgA) are valid and not falsely negative due to IgA deficiency. 1

Understanding the Result

• Normal or elevated total IgA validates IgA-based celiac tests - IgA deficiency occurs in 1-3% of celiac disease patients and would cause falsely low antibody results, but your elevated IgA rules this out 1, 2

• The elevated total IgA itself does NOT indicate celiac disease - What matters for celiac diagnosis are the specific antibodies (tissue transglutaminase IgA and endomysial antibody IgA), not the total IgA level 1

• If your celiac-specific antibodies are negative with elevated total IgA, celiac disease is effectively ruled out and no further celiac-specific workup is needed 1

What Causes Elevated Total IgA

Your elevated total IgA may be due to other conditions unrelated to celiac disease:

• Chronic infections, inflammatory bowel disease, or autoimmune conditions commonly elevate total IgA 1

• Liver disease, including cirrhosis and chronic hepatitis, frequently causes elevated IgA levels 1

• IgA-related disorders such as IgA nephropathy, IgA vasculitis, or IgA monoclonal gammopathy should be considered based on your clinical symptoms 1

Interpreting Your Complete Celiac Panel

The key is looking at your celiac-specific antibodies alongside the total IgA:

• If tissue transglutaminase IgA (tTG-IgA) is elevated - This suggests active celiac disease with 90-96% sensitivity and >95% specificity, and you should proceed to confirmatory testing with endomysial antibody (EMA) and duodenal biopsy 3, 2

• If tTG-IgA is >10 times the upper limit of normal - This correlates strongly with severe intestinal damage and has >98% positive predictive value for celiac disease 1

• If both tTG-IgA and EMA are positive - This combination has virtually 100% positive predictive value for celiac disease, and you should proceed directly to upper endoscopy with at least 6 duodenal biopsies 1, 2

• If tTG-IgA and EMA are both negative with elevated total IgA - Celiac disease is ruled out, and the elevated total IgA should be investigated for other causes 1

Common Pitfall to Avoid

Never confuse elevated total IgA with celiac disease risk - The elevated total IgA actually strengthens confidence in negative celiac-specific antibody results, as it confirms the IgA-based tests are working properly 1

Next Steps Based on Your Results

If celiac antibodies are positive:

• Proceed to upper endoscopy with duodenal biopsy (at least 6 specimens from the second part of duodenum) before starting any dietary changes 3, 2
• Ensure you are consuming adequate gluten (at least 10g daily) before biopsy to avoid false-negative results 1, 4

If celiac antibodies are negative:

• Investigate the elevated total IgA with comprehensive metabolic panel, liver function tests, urinalysis with microscopy, and consider serum protein electrophoresis if clinically indicated 1
• Do not start a gluten-free diet without confirmed celiac disease, as this can lead to nutritional deficiencies and unnecessary dietary restrictions 1