Mortality Excess in Individuals with Elevated IgA Anti-Transglutaminase Antibodies: The KORA/MONICA Augsburg Cohort Study 1989–1998

Abstract

: Immunoglobulin A (IgA) autoantibodies to tissue transglutaminase (tTG) are commonly used for screening and diagnosing of celiac disease. We examined the hypothesis that elevated IgA anti-tTG antibodies were associated with higher all-cause mortality risk. The cohort, 2333 men and 2300 women, was based on the follow-up of participants of a representative population-based survey in Southern Germany (KORA/MONICA Augsburg project) conducted in 1989–1990. The endpoint for the vital status with cause of death was the year 1998. The sera drawn at baseline and stored at −80 °C, were recently screened with an IgA enzyme-linked immunosorbent assay (ELISA) using human recombinant tTG. Age-standardized mortality rates and age-adjusted hazard ratios were calculated. From the 4633 sera analyzed, 63 had an IgA anti-tTG concentration ≥7 AU/ml. Of these 63 individuals, 15 died between 1989 and 1998. The age-adjusted hazard ratio (HRa) of all-cause mortality was 1.86 (95% CI: 1.01–3.41) and 3.92 (95% CI: 1.44–10.71) for men and women, respectively. The excess of cancer mortality was even higher with an HRa of 2.47 (95% CI: 0.89–6.83) in men and of 6.65 (95% CI: 2.04–21.63) in women. Individuals with elevated IgA anti-tTG antibodies had a highly increased mortality risk, particularly due to cancer. New studies are necessary to clarify if this increased risk is due to undiagnosed celiac disease or/and if this elevated IgA anti-tTG antibodies level is a marker of serious diseases like cancer, chronic liver disease or end-stage heart failure.