title: Systemic levels of cytokines and GAD-specific autoantibodies isotypes in Chinese IDDM patients.
abstract: It is not clear if a Th1/Th2 imbalance in Type 1 diabetes (insulin-dependent diabetes mellitus, IDDM) would lead to a particular antigen-specific IgG subclass dominant as had been shown in the mouse model. In new-onset Type 1 diabetics, an autoantibody response to glutamate decarboxylase (GADab) is frequently observed but the GADab subclass repertoire is not well-established. We determined the systemic levels of representative Th1 and Th2 cytokines and the GADab IgG subclass distribution in 41 Chinese IDDM patients of whom 26 were recently diagnosed (< or = 1 year) and 32 had GADab, to ascertain a likely association of antigen-specific antibody isotype and the Th1/Th2 dichotomy. With high-sensitivity ELISA systems that measure sub-picogram cytokine concentrations, 26 of the 41 patients (63.4%) had at least one of the pro-inflammatory Th1 cytokines (TNF-alpha, IFN-gamma and IL-12) detected. Fewer patients (4/41) had the anti-inflammatory Th2 cytokine IL-4 detected. For IL-10, all subjects had measurable quantities but only three diabetics had levels above the upper limit for healthy subjects (n = 20). Grouped according to the profile of detectable cytokines, there were 24 Th1, 2 Th2 and 2 Th0 patterns. GAD-specific IgG1 antibody was more frequently expressed; 22 of 32 GADab[+] patients. The rank order for the GADab subclasses was IgG1 > 4 > 3 > 2; IgG2 was found in 11 GADab[+] patients. Recent-onset diabetics have a similar ranking of the GAD-specific IgG subclasses. In human Type 1 diabetes, a predominance of GAD-specific IgG1 antibody response is observed together with a dominant Th1 cytokine pattern.
authors.affiliation: Department of Medicine, National University of Singapore, Singapore. mdcngwy@nus.edu.sg
authors.forename: W Y
authors.initials: WY
authors.lastname: Ng
authors.forename: A C
authors.initials: AC
authors.lastname: Thai
authors.forename: K F
authors.initials: KF
authors.lastname: Lui
authors.forename: P P
authors.initials: PP
authors.lastname: Yeo
authors.forename: J S
authors.initials: JS
authors.lastname: Cheah
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D002681:China / Q000208:ethnology; D016207:Cytokines / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007132:Immunoglobulin Isotypes / Q000097:blood*; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D018664:Interleukin-12 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D008297:Male; D051379:Mice; D012044:Regression Analysis; D012846:Singapore; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D001323:Autoantibodies; D016207:Cytokines; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma; D005968:Glutamate Decarboxylase