title: HLA-typing, clinical, and immunological characterization of youth with type 2 diabetes mellitus phenotype from the German/Austrian DPV database.
abstract: OBJECTIVE
  To characterize the clinical and immunological features of HLA-typed youth with pediatric onset of type 2 diabetes mellitus (T2DM).
  
  
  METHODS
  One hundred and seven patients with clinically diagnosed T2DM (aged ≤20 yr at diagnosis) were examined. DNA and serum, obtained after a median diabetes duration of 2.2 (Q1-Q3: 0.8-4.6) yr, were used for centralized HLA-typing and autoantibody (GADA, IA-2A, ZnT8A) measurements.
  
  
  RESULTS
  64.6% of patients were female and median age at diagnosis was 13.8 (Q1-Q3: 11.6-15.4) yr. Patients were obese [median body mass index-standard deviation score (BMI-SDS): 2.6 (2.0-3.1)], 88.0% had a family history of diabetes and 40.2% a migration background. Islet autoantibodies were detected in 16 (15.0%), among which 7 (6.5%) had multiple islet autoantibodies. Autoantibody positive patients had poorer metabolic control than autoantibody negative patients [glycosylated hemoglobin A1c (HbA1c): 8.1 (6.9-10.1) % vs. 6.6 (5.9-8.0) %; p = 0.033], while patients with HLA-DR genetic risk had higher BMI-SDS than those with HLA-DRXX [2.6 (2.4-3.7) vs. 2.4 (1.7-2.9); p = 0.007]. Metabolic syndrome (61.7%), microalbuminuria (13.4%), and retinopathy (3.9%) were diagnosed. Therapies used were lifestyle only (35.5%), oral anti-diabetics (OAD) only (43.3 %), insulin +  OAD (15.9%) and insulin only (5.6%). Patients with β-cell autoimmunity or HLA-DR genetic risk more frequently used insulin than confirmed T2DM patients (50.0 vs. 22.0%; p = 0.037) and less often had diabetic relatives (61.1 vs. 86.0%; p = 0.030).
  
  
  CONCLUSIONS
  T2DM was confirmed in about 90% of patients while about 10% with β-cell autoimmunity or HLA-DR genetic risk likely had either T1.5DM or 'double diabetes' or an unknown diabetes type.
authors.affiliation: Faculty of Medicine, Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, 89081, Germany.
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Awa
authors.forename: Bernard O
authors.initials: BO
authors.lastname: Boehm
authors.forename: Silke
authors.initials: S
authors.lastname: Rosinger
authors.forename: Peter
authors.initials: P
authors.lastname: Achenbach
authors.forename: Anette G
authors.initials: AG
authors.lastname: Ziegler
authors.forename: Stephanie
authors.initials: S
authors.lastname: Krause
authors.forename: Thomas
authors.initials: T
authors.lastname: Meissner
authors.forename: Susanne
authors.initials: S
authors.lastname: Wiegand
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinehr
authors.forename: Thomas
authors.initials: T
authors.lastname: Kapellen
authors.forename: Beate
authors.initials: B
authors.lastname: Karges
authors.forename: Thomas
authors.initials: T
authors.lastname: Eiermann
authors.forename: Edith
authors.initials: E
authors.lastname: Schober
authors.forename: Reinhard W
authors.initials: RW
authors.lastname: Holl
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001317:Austria / Q000453:epidemiology; D001323:Autoantibodies / Q000097:blood; D002648:Child; D016208:Databases, Factual / Q000706:statistics & numerical data; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology* / Q000276:immunology*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006683:HLA-DQ Antigens / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D010641:Phenotype
chemical_list: D001323:Autoantibodies; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens
keywords: HLA-DR-genotype; obesity; therapy; type 2 diabetes; β-cell autoimmunity