The purpose of this study is to determine whether early immunological markers (activation of autoreactive T lymphocytes) precede and are predictive of the appearance of autoantibodies in children born from type 1 diabetic parents.

The prevalence of type 1 diabetes (T1D) is estimated between 0.2 and 0.4% in France. The incidence in France is more than 10/105 per year, with a steady increase (~4%/year), especially in children. Infants born to parents with T1D have a 15-fold higher risk to develop T1D compared to the general population. The appearance of autoantibodies precedes and is highly predictive of the later occurrence of T1D. The activation of B lymphocytes, which produce autoantibodies, is controlled by T helper lymphocytes. Hence, biomarkers associated with initial T lymphocyte activation are likely to precede the appearance of autoantibodies.

The aim of the TRAKR study is to determine whether the appearance of autoreactive T lymphocytes is predictive of the emergence of autoantibodies.

The secondary objectives are: 1) to evaluate whether metagenomic, metabolic, or environmental factors are associated with the appearance of autoantibodies; 2) to evaluate the incidence and the time of autoantibody appearance in a French population of genetically at-risk children; 3) to compare the incidence of autoantibodies between infants born to T1D fathers and mothers.

Inclusion Criteria:

1. Mother and/or father with type 1 diabetes

   • age > 18 years
   • type 1 diabetes : insulin-dependent diabetes positive for autoantibodies against insulin and/or GAD and/or IA-2 and/or ZnT8 at the time of diagnosis
   • planning to give birth or having given birth since less than 8 months
   • agreeing to participate upon written informed consent
   • covered by the French social security system

2. Mother/father without Type 1 diabetes

   • age > 18 years old
   • with a spouse with type 1 diabetes : insulin-dependent diabetes positive for autoantibodies against insulin and/or GAD and/or IA-2 and/or ZnT8 at the time of diagnosis
   • planning to give birth or having given birth since less than 8 months
   • agreeing to participate upon written informed consent
   • covered by the French social security system

3. Children born to mother and/or father with type 1 diabetes

   • age < 8 months
   • with at least one parent with T1D
   • with both parents agreeing to participate
   • both parents covered by the French social security system

Exclusion Criteria:

1) Mother/father

• secondary forms of diabetes

• monogenic forms of diabetes

  1 or 2) For the mother

• malignant neoplastic or psychiatric disease

  3 ) Newborns of mother/father with type 1 diabetes

• Severe foetal disease

• Severe congenital malformation

• Congenital measles