Diagnostic role of SOX13 antibody in latent autoimmune diabetes of adults

Abstract

To explore the diagnostic role of SOX13 antibody in latent autoimmune diabetes of adults (LADA). Sera of 328 patients with slow-onset diabetes and 120 sex and age-matched healthy controls underwent radiochemical test to detect the positive rates of SOX13-Ab, glutamic acid decarboxylace antibody (GAD-Ab) and carboxypeptidase H antibody (CPH-Ab). According to the GAD-Ab and CPH-Ab status the patients were divided into autoimmune (GAD-Ab and/or CPH-Ab positive, n = 130) and non-autoimmune (GAD-Ab and CPH-Ab negative, n = 198) diabetic subgroups. Then according to SOX13-Ab, GAD-Ab and CPH-Ab status, the diabetic patients were divided into 4 groups: SOX13-Ab positive, GAD-Ab positive, CPH-Ab positive, and antibody-negative group to compare their clinical characteristics. The effect of SOX13-Ab on islet beta-cell function was evaluated by comparison of C-peptide among the four subgroups. The positive rates of SOX13-Ab in the slow-onset diabetic patients (10.4%), autoimmune subgroup patients (13.1%), and non-autoimmune subgroup patients (8.6%) were all higher than that in the healthy controls (2.5%, all P < 0.05). Thirteen patients were positive for both SOX13-Ab and CPH-Ab (13/328, 4.0%), but only 2 were positive for both SOX13-Ab and GAD-Ab (2/328, 0.6%). The highest prevalence of SOX13-Ab was observed in the patients with the duration of disease ranging from 16 to 20 years. There were no differences in the clinical parameters between the SOX13-Ab positive and antibody-negative diabetic patients. SOX13-Ab testing helps improve the sensitivity of screening for LADA. SOX13-Ab positive patients tend to have a longer course of disease and varied clinical manifestations.