From the Guidelines
Your Tissue Transglutaminase (tTG) IgA level of 209.5 KIU/L is significantly elevated, strongly suggesting celiac disease, and you should immediately consult with a gastroenterologist for confirmation, which typically requires an intestinal biopsy while still consuming gluten, as recommended by the most recent guidelines 1.
Key Points to Consider
- The elevated tTG IgA level indicates your immune system is reacting to gluten by producing antibodies against the tissue transglutaminase enzyme, with normal levels typically below 20 KIU/L, and your reading of 209.5 KIU/L represents a strong positive result, according to a systematic review with meta-analysis 1.
- Do not start a gluten-free diet before completing diagnostic testing, as this can affect results, and reduction or avoidance of gluten prior to diagnostic testing is discouraged, as it may reduce the sensitivity of both serology and biopsy testing, as stated in the AGA clinical practice update 1.
- Once confirmed, you'll need to follow a strict lifelong gluten-free diet, eliminating wheat, barley, and rye from your meals, to manage the condition and prevent complications, as recommended by guidelines for best practices in monitoring established coeliac disease in adult patients 1.
- The gastroenterologist may also check for nutritional deficiencies common in celiac disease, such as iron, vitamin D, vitamin B12, and folate, as the condition damages intestinal villi that absorb these nutrients, and determination of HLA-DQ2/DQ8 has a limited role in the diagnosis of CD, but can be useful in ruling out the condition in certain cases, as noted in the guidelines 1.
From the Research
Tissue Transglutaminase IgA Levels
- The given level of Tissue Transglutaminase IgA is 209.5 KIU/L.
- According to the studies, the normalization of Tissue Transglutaminase IgA levels in patients on a gluten-free diet depends on the assay used 2.
- A study found that 40% of samples taken after at least 6 months on a gluten-free diet with elevated intestinal fatty acid binding protein (i-FABP) had positive Tissue Transglutaminase IgA according to one assay, while 85 and 90% were positive according to two other assays 2.
Comparison of Assays
- Different assays may yield different results for Tissue Transglutaminase IgA levels, with some being more sensitive than others 2, 3.
- A study compared the use of IgA anti-tTG2 antibody levels in adult celiac disease patients and found that serum levels were significantly elevated in patients without a gluten-free diet compared to those with a gluten-free diet 3.
- Another study found that IgA anti-tTG antibody levels correlated inversely with the duration of a gluten-free diet 3.
Effects of Gluten-Free Diet
- A gluten-free diet has been shown to reduce Tissue Transglutaminase IgA levels in patients with celiac disease 4, 5.
- A study found that IgA-tTG levels decreased to 76 U/ml after 6 months on a gluten-free diet, with 60% of children having reduced their IgA-tTG levels to < 100 U/ml 4.
- Another study found that serum tTG(IgA) levels decreased to 94.88±55.35 U/mL from a baseline level of 202±83.96 U/mL after 6 months on a gluten-free diet 5.