Can tTG IgA help with fatigue?

The tTG IgA test (tissue transglutaminase IgA) is a well-established screening marker for celiac disease. Chronic fatigue can be a symptom of undiagnosed celiac disease due to nutrient malabsorption (iron, vitamin B12, folate) and systemic inflammation. However, the test does not directly measure fatigue; it detects an autoimmune response to gluten. A positive tTG IgA requires confirmatory small bowel biopsy. If negative but fatigue persists, other causes (thyroid, iron deficiency, sleep disorders, depression) should be investigated. The test is appropriate when celiac disease is clinically suspected, but not as a general fatigue screening. Caveat: A negative test does not completely rule out celiac disease (especially with IgA deficiency). The evidence linking tTG IgA to fatigue is indirect but well-supported (human-strong for celiac diagnosis).