Autoimmunity in latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is clinically characterized by onset after age 30, absence of ketoacidosis, insulin independence for at least 6 months after diagnosis, and presence of circulating islet-cell antibodies. These include glutamic acid decarboxylase (GADA) autoantibodies, tyrosine phosphatase-2 autoantibodies, or zinc-transporter 8 autoantibodies. In particular, GADA are the most frequent autoantibody in LADA and can be detected in serum for many years post diagnosis. High concentrations of GADA have been considered as a marker of faster islet-cell exhaustion in these patients. Moreover, LADA patients have other circulating non islet antibodies, such as antibodies against thyroperoxidase and antibodies against gastric parietal cells, that reflect the presence of a high intensity of immune processes. Although the presence of each antibody taken individually shows scarce predictive value for the progression of the disease, their simultaneous presence might predict the insulin dependence in this LADA subgroup. The occurrence of islet autoantibodies in these patients might identify specific phenotypes of LADA with more homogeneous characteristics that are prone to faster exhaustion of beta cell function. The high prevalence of these autoantibodies is clinically relevant and their measurement should be introduced as screening in clinical practice in order to identify the clinical presence of other organ specific autoimmune diseases.