RESUMO
OBJECTIVE: To investigate the allelic frequency of histocompatibility leukocyte antigen (HLA)-DRB of gestational diabetes mellitus (GDM) women, in order to find out the susceptible or protective gene associated with GDM and the relationship between HLA-DRB genes and the clinical characteristic. METHODS: Thirty GDM women served as study group, 40 normal pregnant women were selected as control group. The distribution of HLA-DRB alleles frequency of 30 GDM and 40 normalpregnant women was examed by polymerase chain reaction sequence specific primer (PCR-SSP). RESULTS: There was significantly increased gene frequency of HLA-DR6 (13) in GDM women compared with normal pregnancy (12% Vs 2%, P < 0.05, RR = 5.8). The frequency of HLA-DR3 and HLA-DR9 gene in GDM women were increased, but the statistical difference was not significant (8% Vs 4%, 23% Vs 16%, P > 0.05). A much lower frequency of HLA-DR2 (15), HLA-DR51 were observed in GDM women than in normal pregnancy (10% Vs 24%, P < 0.05; 10% Vs 38%, P < 0.05). There were relationship between HLA-DR3 gene or HLA-DR6 (13)/DR9 heterozygote and severe type of GDM, relative risk (RR) were 27.1 and 8.5 respectively; HLA-DR6 (13)/DR9 heterozygote or HLA-DR3 gene were also correlated with abnormal plasma glucose levels. CONCLUSIONS: Alleles HLA-DR6 (13) were significantly implicated in their susceptibility to GDM. Conversely, HLA-DR2 (15), HLA-DR51 alleles might confer protection against GDM. HLA-DR3 gene and HLA-DR6 (13)/DR9 heterozygote were associated with severity and prognosis of GDM. It may be a marker of grade and prognosis of GDM and may direct the treatment.