This study has confirmed the high prevalence of nonislet, organ-specific autoantibodies in individuals with type 1 diabetes and indicates that for many, these autoantibodies are present at diagnosis. Previous studies have confirmed the prevalence of these antibodies (3
) and the effect of these autoantibodies on type 1 diabetes control (12
). Additionally, within an average of 45 days after type 1 diabetes diagnosis, 19% of individuals with nonislet, organ-specific autoantibodies were diagnosed with clinical disease. These comorbid conditions were likely present at type 1 diabetes onset, given clinical practice to repeat positive autoantibody tests and perform confirmatory testing, which may take several months to coordinate.
Twice as many children were positive for TPOAb as TTGAb. However, an equal number of children were diagnosed with CD as with AIT. Analysis of HLA confirms a relationship between the HLA-DR3
allele and TTGAb positivity (7
). Further genetic typing will be important to identify additional genes that may contribute to the presence of organ-specific autoimmunity and development of disease.
This study is limited because it only monitored subjects for a short period after their diagnosis of type 1 diabetes, and confirmatory small-intestinal biopsies for CD were not performed on all TTGAb+ subjects.
Ongoing follow-up of this cohort will be important to determine the natural history of organ-specific autoimmunity in patients with type 1 diabetes. Key questions remain, including the incidence of autoantibodies over time, the evolution from positive antibodies to disease, the genetic influences on autoimmunity and disease, and patient characteristics that may influence antibody or disease development.
The strategy for screening for these autoantibodies is a source of ongoing debate (13
). However, given the high preponderance of these antibodies at the onset of type 1 diabetes, we recommend screening for AIT, CD, and AD.
We have shown that 32.6% of patients with type 1 diabetes are positive for at least one additional organ-specific autoantibody at the diagnosis of type 1 diabetes, and 18.6% had clinical disease. This is important for the clinical care of patients with type 1 diabetes and may provide insight into the pathogenesis of these complex diseases.