Researchers recently screened stored serum samples of over 6,000 individuals who participated in a National Health and Nutrition Examination Survey (NHANES III: 1988-1992). Each sample was tested for IgA anti-tTG and IgA endomysial antibodies, with the intention of determining whether a positive test correlated with increased risk of mortality in those age 50 and older.
Blood testing for IgA antibodies is increasingly being used for celiac disease diagnosis; coupled with IgA endomysial antibodies (EMA), the test can produce greater than 95% accuracy in celiac disease diagnosis. It is important to note, however, that these same antibodies can sometimes be found in individuals without celiac disease, but with other health conditions such as chronic liver disease, heart failure, and autoimmune disorders. In the case of this particular study, the presence or absence of IgA anti-tTG was used as the defining factor between the case and control groups; whether these individuals actually had celiac disease was not assessed.
Past population-based studies have given contradictory findings about the risk of increased mortality with celiac disease, be it diagnosed or undiagnosed, and one European study concluded a higher risk for those with elevated serology. Researchers sought to perform a similar, systematic study for the United States.
Eighty five of the tested samples were found to be positive for IgA anti-tTG. After correlating with National Death Index certificate records and statistically adjusting for age, sex, smoking, and race, the only statistically significant effect was seen for men over the age of 50, who were found to have life expectancy about 1.6 years shorter than their IgA negative counterparts. While cardiovascular disease was the listed cause of death for the largest number of seropositive individuals (36/85), 19% of individuals whose cause of death was listed as respiratory disease were also IgA anti-tTG positive.
While this certainly merits further research, this study suggests that men over 50 with elevated IgA anti-tTG antibodies are at increased mortality, and that such elevation could be a nonspecific marker of serious disease.
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Elevated Serology a Red Flag for Men Over 50