Organ-specific antibodies in LADA patients for the prediction of insulin dependence

Aim of the study: The aim of the present study was to define the frequency of organ-specific and non-organ-specific autoantibodies in a cohort of Latent Autoimmune Diabetes in Adults (LADA)
patients and to test whether multiple antibodies positivity could be a predictor of early insulin
dependence.
Materials and methods: We enrolled 210 LADA and 210 type 2 diabetes mellitus (T2D)
patients. In all subjects anti-islet antigen-2 (IA-2Ab), anti-thyroperoxidase (TPOAb), anti-zinc transporter 8 (ZnT8Ab), anti-nuclear (ANA), anti-parietal cell (APCA), anti-smooth muscle (ASMA), anti-mitochondrial (AMA), anti-liver kidney microsomes (LKM) and anti-reticulin
(ARA) circulating antibodies were assessed.
Results: The frequency of TPOAb, ZnT8Ab, APCA, and IA-2Ab positivity was respectively detected in 40.0%, 32.4%, 24.7%, and 9.5% of LADA patients, whereas their frequency was
significantly lower in T2D patients (11.4%, 1.9%, 9.5%, and 0.0% respectively, p <0.001). The frequency of ANA was the same in both groups while the frequency of ASMA, ARA, AMA, and LKM was very low (range 0.0-3.3%). The presence of TPOAb associated with either ZnT8Ab, IA-2Ab or APCA allows to predict the progression of disease with a high specificity but low sensitivity.
Conclusions: LADA patients show an increased frequency of organ- and non-organ-specific antibodies. Consequently, a screening is worthwhile in these patients. The simultaneous presence
of TPOAb with either ZnT8, IA-2Ab or APCA may help to differentiate clinical phenotypes and to predict faster insulin dependence in LADA patients.