Autoimmunity in gestational diabetes mellitus in Sardinia: a preliminary case-control report.
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.
Murgia
Cinzia
C
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
Orrù
Marisa
M
Portoghese
Elaine
E
Garau
Nicoletta
N
Zedda
Pierina
P
Berria
Rachele
R
Motzo
Costantino
C
Sulis
Simonetta
S
Murenu
Michela
M
Paoletti
Anna Maria
AM
Melis
Gian Benedetto
GB
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
D001323:Autoantibodies; C096322:ICA512 autoantibody; D007330:Insulin Antibodies; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2