Mortality excess in individuals with elevated IgA anti-transglutaminase antibodies: the KORA/MONICA Augsburg cohort study 1989-1998.

OBJECTIVES: 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.

METHODS: 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 degrees 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.

RESULTS: From the 4633 sera analyzed, 63 had an IgA anti-tTG concentration>or=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 HR(a) of 2.47 (95% CI: 0.89-6.83) in men and of 6.65 (95% CI: 2.04-21.63) in women.

CONCLUSIONS: 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.