Autoantibodies against islet cell antigens in children with type 1 diabetes mellitus

// Bi-Wen Cheng 1, 8, * , Fu-Sung Lo 2, 3, * , An-Mei Wang 4, 6 , Chen-Mei Hung 5 , Chi-Yu Huang 1, 6 , Wei-Hsin Ting 1, 6 , Mei-Ore Yang 7 , Chao-Hsu Lin 8 , Chia-Ching Chen 9 , Chiung-Ling Lin 10 , Yi-Lei Wu 11 and Yann-Jinn Lee 1, 10, 12, 13, 14 1 Department of Pediatric Endocrinology, MacKay Children's Hospital, Taipei, Taiwan 2 Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan 3 College of Medicine, Chang Gung University, Taoyuan, Taiwan 4 Department of Nuclear Medicine, MacKay Memorial Hospital, Taipei, Taiwan 5 Department of Pediatrics, Hsinchu Cathay General Hospital, HsinChu, Taiwan 6 MacKay Medicine, Nursing and Management College, New Taipei City, Taiwan 7 Department of Laboratory Medicine, MacKay Memorial Hospital, Taipei, Taiwan 8 Department of Pediatrics, MacKay Memorial Hospital HsinChu Branch, HsinChu, Taiwan 9 Department of Pediatrics, Chiayi Christian Hospital, Chiayi, Taiwan 10 Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan 11 Department of Pediatric Endocrinology and Metabolism, Chuanghua Christian Children’s Hospital, Chuanghua, Taiwan 12 Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan 13 Department of Medicine, Mackay Medical College, New Taipei City, Taiwan 14 Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan * These authors contributed equally to this work Correspondence to: Yann-Jinn Lee, email: yannlee@mmh.org.tw Keywords: autoantibodies; glutamic acid decarboxylase 65 (GAD) autoantibody; insulinoma-associated protein 2 autoantibody; insulin autoantibody; type 1 diabetes mellitus; Immunology Received: December 12, 2016 Accepted: February 13, 2018 Epub: February 19, 2018 Published: March 27, 2018 ABSTRACT We investigated the prevalence of glutamic acid decarboxylase 65 autoantibody (GADA), insulinoma-associated protein 2 autoantibody (IA2A), and insulin autoantibody (IAA) in 750 children with type 1 diabetes (T1D) living in Taiwan. GADA, IA2A, and IAA were measured by radioimmunoassay. The data were assessed by χ 2 test, binary logistic regression, and Spearman rank correlation. Of the 750 T1D patients, 66.3% had GADA, 65.3% IA2A, 35.7% IAA, and 17.2% no autoantibodies. The prevalence of GADA and IA2A significantly decreased along T1D duration. The positivity of either GADA or IA2A was 89.4% within the first year of disease and decreased to 36.7% after 9 years ( P = 1.22 × 10 –20 ). Female patients had significantly higher prevalence of GADA compared with male patients (72.3% vs. 59.7%, P = 0.00027). The patients diagnosed before 12 years of age had a positive rate of 92.2% for either GADA or IA2A. Patients diagnosed at age 12 or above had a significantly lower positive rate of 81.6% ( P = 0.011). GADA and IA2A significantly correlated with each other (rs = 0.245, P = 1.09 × 10 –11 ). We concluded that autoantibodies were detectable in 89.4% of T1D patients within one year after diagnosis. Their prevalence declined with disease duration. GADA was more prevalent in female patients. GADA and IA2A weakly correlated with each other.