title: Persistence of glutamic acid decarboxylase antibody (GADA) is associated with clinical characteristics of latent autoimmune diabetes in adults: a prospective study with 3-year follow-up.
abstract: Latent autoimmune diabetes in adults (LADA) is a form of autoimmune diabetes with heterogeneous features. This study aimed to investigate the persistent status of glutamic acid decarboxylase antibody (GADA) in patients with LADA and its association with clinical characteristics.
  
  
  
  This 3-year follow-up study enrolled 107 LADA and 40 type 2 diabetes mellitus (T2DM) patients from October 2005 to December 2013. GADA titer, epitopes, and clinical characteristics (including fasting C-peptide and HbA1c ) in LADA patients were assayed annually. The human leukocyte antigen DQ (HLA-DQ) genotypes were also analysed. The relationship between the persistence of GADA and the clinical characteristics was investigated in LADA patients.
  
  
  
  After 3-year follow-up, 36.5% (39/107) LADA patients remained GADA positive (persistently positive group), 19.6% (21/107) patients fluctuated positively and negatively (fluctuating group), and 43.9% (47/107) patients became GADA negative, among which 61.7% (29/47) seroconversions occurred within 6 months of follow-up (transiently positive group). The GADA persistently positive group possessed higher titer of GADA than transiently positive group and fluctuant group (all p = 0.000), higher reactivities to middle and C-terminal regions of GAD65 than those in transiently positive group (p = 0.001 and p = 0.000, respectively), and lower baseline fasting C-peptide level than T2DM patients and transiently positive group [415(31-1862) vs 620(220-1658) pmol/L, p = 0.014; and 415(31-1862) vs 705(64-1541) pmol/L, p = 0.017, respectively]. The GADA transiently positive group retained a higher HbA1c level when compared with T2DM patients (p = 0.023). In addition, the three LADA groups shared similar frequencies of HLA-DQ susceptible haplotypes that were higher as compared with T2DM. The GADA persistently positive group had a higher annual declining rate in fasting C-peptide than T2DM patients [-14%(-174-33%) vs -1%(-27-28%), p = 0.007].
  
  
  
  The LADA patients with GADA transient positivity account for a large proportion, whose clinical characteristics and HLA-DQ haplotypes are different from those of T2DM. The patients with high titer GADA and reactivities to GADA65 middle and C-terminal regions showed a persistent GADA positivity, in which a worse baseline and accelerated decline of β-cell function need early intervention in the practice. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Gan
authors.initials: G
authors.lastname: Huang
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yin
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Shuoming
authors.initials: S
authors.lastname: Luo
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Peilin
authors.initials: P
authors.lastname: Zheng
authors.affiliation: Institute of Metabolism and Endocrinology, The Second Xiangya Hospital, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, National Clinical Research Centre for Metabolic Diseases, Changsha, Hunan, 410011, China.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000276:immunology*; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D000071698:Latent Autoimmune Diabetes in Adults / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies
chemical_list: D001323:Autoantibodies; D005968:Glutamate Decarboxylase
keywords: glutamic acid decarboxylase antibody; latent autoimmune diabetes in adults; type 2 diabetes mellitus; β-cell function