Evidence check: tTG IgA in the context of Langlebigkeit

A positive tTG IgA test is a strong indicator of celiac disease but not diagnostic on its own. Tissue transglutaminase (tTG) is the main autoantigen in celiac disease, and elevated IgA antibodies have high sensitivity and specificity (>95%). However, current guidelines require duodenal biopsy with histological evidence of villous atrophy for confirmation, especially in adults. False positives can occur in other autoimmune conditions or rarely in liver disease. In the context of longevity, untreated celiac disease can lead to malabsorption (iron deficiency, osteoporosis), chronic inflammation, and increased risk of non-Hodgkin lymphoma, potentially reducing life expectancy. A strict gluten-free diet normalizes antibodies and significantly lowers complication risks. The evidence is strong (human-observational, guidelines), but the provided context lacks specific information on tTG IgA. Thus, this answer relies on general medical knowledge. Caveat: A positive test without biopsy confirmation may lead to misdiagnosis. In IgA deficiency, the test can be falsely negative; then IgG tTG or EMA should be considered.