Influência da diabetes gestacional na produção de anticorpos anti-insulina e citocinas no colostro e na saliva

Abstract

Maternal hyperglycemia may interfere with the composition and with the concentration of immunological mediators in colostrum. However, there is little evidence on the concentration of antibodies and cytokines in colostrum of mothers who developed gestational diabetes. Thus, our aim was to evaluate the concentration of anti-insulin IgA antibodies and the cytokine concentration in colostrum compared to the saliva of pregnant women who developed gestational diabetes. It was a casecontrol study conducted at the Hospital Materno Infantil of the Federal University of Maranhão. The protocol was registered at Plataforma Brasil and approved by CEPHUUFMA (No. 3.301.629). The study evaluated 74 women, 37 in the gestational diabetes group and 37 in the non-diabetic group. The colostrum was collected manually, always in the morning, 48 hours after delivery and the saliva collection was performed after 2 hours fasting and oral hygiene with filtered water. Saliva and colostrum were centrifuged (2,000 rpm) and the supernatant used to determine the antibodies and cytokines concentrations by Enzyme-linked immunosorbent assay (ELISA) and Cytometric Beads Array (CBA). The biochemical determination of glucose, cholesterol, triglycerides, urea and amylase concentrations were performed in an automated system. Statistical analysis used the Student's t-test for samples with normal distribution and Mann-Whitney test to compare ordinal or continuous variables without normal distribution. The average age of women with gestational diabetes was 31 years. Among newborns of diabetic mothers, 27% had fetal macrosomia and 30% were hypoglycemic, within the first 24 hours of life. The highest concentrations of glucose, cholesterol, calcium, anti-insulin IgA and IL-10 occurred in colostrum in women with gestational diabetes. This group also showed a reduction in IFN-γ and TGF-β concentrations. The total concentration of triglycerides, total protein, IgA, TNF-α and IL-17 was not different between the two groups. The increase in antiinsulin IgA in colostrum showed a positive correlation with TNF-α. In contrast the increase of anti-insulin antibodies showed a negative correlation with TGF-β. This seems to be the first report concerning the increase of anti-insulin antibodies in colostrum from women with gestational diabetes and their influence on the cytokine concentration. Considering that anti-insulin antibodies are among the most frequent humoral markers in the loss of self-tolerance, our results indicate that immunological evaluations are important to qualify the milk of women with gestational diabetes, since the repercussion of this increase in the immune system of the babies is not known. Those results opens new perspectives for further studies aiming to follow-up of these women and their children during a longer period.