Objective: To explore the diagnostic role of SOX13 antibody in latent autoimmune diabetes of adults (LADA).
Methods: 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.
Results: 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.
Conclusion: 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.