Does an Immunoglobulin A (IgA) level of 249 indicate a positive result for celiac disease on a celiac lab test?

From the Guidelines

An IgA level of 249 on a celiac lab test does not by itself indicate a positive result for celiac disease. This value represents your total IgA immunoglobulin level, which is typically measured to ensure you can produce enough antibodies for the celiac-specific tests to be reliable, as noted in a systematic review with meta-analysis published in 2022 1. For celiac disease diagnosis, doctors look specifically at tissue transglutaminase antibodies (tTG-IgA) or endomysial antibodies (EMA-IgA), not just the total IgA level.

Key Points to Consider

• A normal total IgA level (usually between 70-400 mg/dL for adults) simply means that the other celiac-specific antibody tests can be interpreted correctly.
• To determine if you have celiac disease, you would need to look at the results of these specific antibody tests, along with symptoms and possibly an intestinal biopsy, as outlined in guidelines from the British Society of Gastroenterology 1.
• The accuracy of serological tests for coeliac disease has been evaluated in a systematic review with meta-analysis, which found that these tests are highly sensitive and specific in both adults and children 1.

Next Steps

If you're concerned about possible celiac disease, discuss the complete panel of test results with your healthcare provider for proper interpretation. They will consider the results of the specific antibody tests, your symptoms, and possibly an intestinal biopsy to make a diagnosis. Some key considerations for diagnosis include:

• The presence of symptoms such as gastrointestinal symptoms, including diarrhoea, nausea, vomiting and abdominal pain, and extraintestinal symptoms such as fatigue and weight loss.
• The results of serological tests, including tissue transglutaminase antibodies (tTG-IgA) or endomysial antibodies (EMA-IgA).
• The presence of villous atrophy on intestinal biopsy. It's essential to follow the guidance of your healthcare provider and undergo the recommended tests to determine if you have celiac disease.

From the Research

Celiac Lab Test Results

• An IG A OF 249 on a celiac lab test is not directly addressed in the provided studies, but we can look at the general guidelines for interpreting celiac lab test results.
• The studies suggest that tissue transglutaminase (tTG) IgA antibodies are a hallmark for celiac disease (CD) 2, 3, 4.
• However, the cutoff values for positive results vary depending on the assay used, with some studies using a cutoff of 4 units/mL 3 and others using 20 units/mL 2.

Interpretation of Results

• Without knowing the specific cutoff value used in the lab test, it is difficult to determine if an IG A OF 249 is positive or negative for celiac disease.
• The studies suggest that IgA anti-tTG levels can be used to monitor response to a gluten-free diet, but the normalization of these levels depends on the assay used 2.
• It is also important to note that some patients with celiac disease may have selective IgA deficiency, which can affect the interpretation of lab results 4.

Comparison of Assays

• The studies compare the performance of different tTG-IgA assays, including fluorochrome-enzyme immuno-assay (FEIA) and chemiluminescence immuno-assays (CLIA) 2.
• The results suggest that CLIA assays may be more sensitive in detecting suboptimal treatment response in CD patients, but the choice of assay and cutoff value can affect the interpretation of results 2, 3.