title: Autoimmunity in gestational diabetes mellitus in Sardinia: a preliminary case-control report.
abstract: BACKGROUND
  We previously reported a high prevalence (22.3%) of gestational diabetes mellitus (GDM) in a large group of Sardinian women, in contrast with the prevalence of Type 2 diabetes. Sardinia has an unusual distribution of haplotypes and genotypes, with the highest population frequency of HLA DR3 in the world, and after Finland, the highest prevalence of Type 1 diabetes and Autoimmune-related Diseases. In this study we preliminarily tested the prevalence of serological markers of Type 1 diabetes in a group of Sardinian GDM patients.
  
  
  METHODS
  We determined glutamic decarboxylase antibodies (anti-GAD65), protein tyrosine phosphatase ICA 512 (IA2) antibodies (anti-IA2), and IAA in 62 GDM patients, and in 56 controls with matching age, gestational age and parity.
  
  
  RESULTS
  We found a high prevalence and very unusual distribution of antibodies in GDM patients (38.8%), the anti-IA2 being the most frequent antibody. Out of all our GDM patients, 38.8% (24 of 62) were positive for at least one antibody. Anti-IA2 was present in 29.0 % (18 out of 62) vs. 7.1% (4 out of 56) in the controls (P < 0.001). IAA was present in 14.5% (9 out of 62) of our GDM patients, and absent in the control subjects (P < 0.001). Anti-GAD65 was also present in GDM patients, with a prevalence of 3.2% (2 out of 62) while it was absent in the control group (P = NS). Pre-gestational weight was significantly lower (57.78 +/- 9.8 vs 65.9 +/- 17.3 P = 0.04) in auto-antibodies- positive GDM patients.
  
  
  CONCLUSIONS
  These results are in contrast with the very low prevalence of all antibodies reported in Italy. If confirmed, they could indicate that a large proportion of GDM patients in Sardinia have an autoimmune origin, in accordance with the high prevalence of Type 1 diabetes.
authors.affiliation: Dipartimento Chirurgico Materno Infantile e di Scienza delle Immagini, Sezione di Clinica Ginecologica, Ostetrica e Fisiopatologia della Riproduzione Umana, Universita' degli Studi di Cagliari, Italy. cinziamurgia@tiscali.it
authors.forename: Cinzia
authors.initials: C
authors.lastname: Murgia
authors.forename: Marisa
authors.initials: M
authors.lastname: Orrù
authors.forename: Elaine
authors.initials: E
authors.lastname: Portoghese
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Garau
authors.forename: Pierina
authors.initials: P
authors.lastname: Zedda
authors.forename: Rachele
authors.initials: R
authors.lastname: Berria
authors.forename: Costantino
authors.initials: C
authors.lastname: Motzo
authors.forename: Simonetta
authors.initials: S
authors.lastname: Sulis
authors.forename: Michela
authors.initials: M
authors.lastname: Murenu
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Paoletti
authors.forename: Gian Benedetto
authors.initials: GB
authors.lastname: Melis
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D015551:Autoimmunity; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000276:immunology*; D016640:Diabetes, Gestational / Q000453:epidemiology* / Q000276:immunology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology; D006801:Humans; D007330:Insulin Antibodies / Q000097:blood; D007558:Italy / Q000453:epidemiology; D010298:Parity; D011247:Pregnancy; D012307:Risk Factors; D016036:Seroepidemiologic Studies
chemical_list: D001323:Autoantibodies; C096322:ICA512 autoantibody; D007330:Insulin Antibodies; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2