Increased mortality among men aged 50 years old or above with elevated IgA anti-transglutaminase antibodies: NHANES III.
BACKGROUND
Immunoglobulin A (IgA) antibodies to tissue transglutaminase (tTG) are the serologic test of choice for diagnosing celiac disease (CD). Our aim was to determine if elevated IgA anti-tTG were associated with increased mortality risk.


METHODS
Stored serum samples of National Health and Nutrition Examination Survey (NHANES) III (1988-1992) were available for 6032 individuals aged 50 years old or above, which were screened for IgA anti-tTG, and if positive, for IgA endomysial antibodies. Mortality was determined from the National Death Index records through 2006. Hazard ratios were calculated through Cox proportional hazards regression.


RESULTS
From a total of 6032, 85 participants tested positive for IgA anti-tTG (1.4 %) and 5947 tested negative. After a median follow-up of 13 years, IgA anti-tTG positive participants were at increased risk of death in both crude (HR = 1.68; 95 % CI = 1.30-2.18) and adjusted analyses (adjusted hazard ratio = 1.43; 95 % CI = 1.10-1.85) as compared to IgA anti-tTG negative participants. The excess mortality was restricted to IgA anti-tTG positive males (adjusted hazard ratio = 1.69 (95 % CI = 1.26-2.29), as opposed to a hazard ratio of 0.96 (95 % CI = 0.57-1.62) among IgA anti-tTG positive females. Although the most common cause of death in IgA anti-tTG positive participants was cardiovascular disease (36 %), the increased hazard ratio was only observed in respiratory cause of death as compared to IgA anti-tTG negative participants (adjusted hazard ratio = 5.11; 2.76-9.46).


CONCLUSIONS
Men aged 50 years old or above participants of NHANES III with elevated IgA anti-tTG antibodies had increased mortality risk. Elevated IgA anti-tTG antibodies could be a nonspecific marker of serious disease in older men.
Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
Alberto
A
Rubio-Tapia
Deparment of Pediatrics, Orebro University Hospital, Orebro, Sweden.|Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Jonas F
JF
Ludvigsson
Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
Rok Seon
RS
Choung
Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
Tricia L
TL
Brantner
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
S Vincent
SV
Rajkumar
Multiple Myeloma Section, Lymphoid Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.|Myeloma Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA.|National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA.
Ola
O
Landgren
Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA. murray.joseph@mayo.edu.
Joseph A
JA
Murray
D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002446:Celiac Disease / Q000276:immunology / Q000401:mortality*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D016016:Proportional Hazards Models; D012737:Sex Factors; D011503:Transglutaminases / Q000276:immunology*; D014481:United States / Q000453:epidemiology
D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D011503:Transglutaminases
Epidemiology; Survival; Transglutaminase