Methodology

Autoimmunity in gestational diabetes mellitus in Sardinia: a preliminary case-control report

Cinzia Murgia¹ , Marisa Orrù¹ , Elaine Portoghese¹ , Nicoletta Garau¹ , Pierina Zedda¹ , Rachele Berria² , Costantino Motzo¹ , Simonetta Sulis¹ , Michela Murenu¹ , Anna Maria Paoletti¹ and Gian Benedetto Melis¹

¹  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

²  Department of Obstetrics and Gynecology, Case Western Reserve University, 44109 Cleveland, Ohio, USA

author email corresponding author email

Reproductive Biology and Endocrinology 2008, 6:24doi:10.1186/1477-7827-6-24

Published:	29 June 2008

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.

Conclusion

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.