Understanding Lab Tests for IgA Deficiency
Written by Private MD Labs Medical Writing Team • Last Updated: September 8, 2025
IgA deficiency is an immune system disorder where the body doesn't produce enough Immunoglobulin A (IgA), a type of antibody that plays a crucial role in protecting mucous membranes. While blood tests can measure IgA levels directly, related antibody tests are fundamental for assessing complications and identifying conditions that may be masked by the deficiency.
Top Recommended Test
Gliadin (Deamidated Peptide) Antibody (IgG, IgA)
This comprehensive test measures both IgG and IgA antibodies to gliadin peptides. For individuals with IgA deficiency, the IgA component may be negative even if celiac disease is present, but the IgG component can still detect gluten-related immune responses, making it crucial for accurate diagnosis when IgA deficiency is suspected.
2907 reviews
Why Specific Antibody Testing is Important in IgA Deficiency
People with IgA deficiency may have false-negative results on standard IgA-based tests for conditions like celiac disease. This is because their bodies cannot produce sufficient IgA antibodies, even when exposed to triggers like gluten. Testing alternative antibody types and understanding IgA levels becomes essential for proper diagnosis and health monitoring.
Other Relevant Tests
Anti-tTG IgA (Tissue Transglutaminase IgA)
This test measures IgA antibodies against tissue transglutaminase, typically used to screen for celiac disease. In individuals with IgA deficiency, low levels of tTG IgA in the presence of symptoms might actually indicate the underlying IgA deficiency rather than ruling out celiac disease, making it valuable for assessing immune function.
2907 reviews
Understanding Test Results in IgA Deficiency
When IgA deficiency is present, healthcare providers must interpret antibody test results differently. Low or absent IgA-based results don't necessarily rule out conditions like celiac disease, and alternative testing approaches using IgG antibodies become more reliable for diagnosis.
Important Considerations
The information here is for educational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider for proper diagnosis and treatment of IgA deficiency and related conditions.
