Disease-associated autoantibodies as predictive markers of type 1 diabetes mellitus in siblings of affected children

Abstract

The long latent preclinical period of type 1 diabetes mellitus (DM) makes it possible to identify individuals at increased risk for clinical DM before the beta-cell destructive process has reached the point of no return. A series of reports on the predictive value of DM-associated autoantibodies are available in first-degree relatives of patients with type 1 DM, but only a few of these studies target exclusively siblings and young siblings of affected children. When planning screening of siblings for DM risk, their age needs to be considered, as predictive characteristics of autoantibodies seem to vary in different age groups. Autoimmunity may be initiated early in life and therefore early screening for signs of beta-cell autoimmunity is crucial to avoid missing young children en route to overt DM and to be able to start intervention, when clinically applicable preventive modalities become available, before the disease process has advanced too far. Young age, positivity for at least two autoantibodies, high levels of autoantibodies and low first phase insulin response are highly predictive for progression to clinical disease in initially unaffected siblings of children with type 1 DM.