Polymorphisms of isotypes of citokines : correlation to intrauterine growth restriction and pre-eclampsia

Background: Type-1 to type-2 cytokine shift is expected in normal pregnancy and correlated to a good pregnancy outcome. Recently, DNA polymorphisms of isotypes of citokines have been correlated to the risk of developing Alzheimer disease. Placental pathology leading to intrauterine growth restriction (IUGR) and/or pre-eclampsia (PE) is due to an anomalous materno-fetal immunitary adaptation. We hypothesize that the risk of IUGR and PE are correlated to peculiar citokines polymorphisms. Objective: The aims of this study were: 1) to test the possibility of assessing polymorphisms of isotypes of citokines in complicated pregnancies by studying mononucleated peripheral blood cells (PBMC); 2) to identify and codifying different isotypes of citokines related to IUGR and/or PE. Methods: ten singleton pregnancies complicated by severe IUGR and/or early-onset PE delivered <30 weeks were included in this preliminary analysis. EDTA-treated blood samples (10 ml) and cord blood samples (7 ml) were obtained from each woman. PBMC were obtained by centrifugation. DNA was extracted from PBMCs using the GENTRA kit. The purified DNA was amplified by PCR-SSP methodology using Cytokine Genotyping Tray (One Lambda, Inc., Canoga Park, CA, Usa) which provides sequence-specific oligonucleotides primers for amplification of selected cytokines (TNF, IFN, TGF, IL6, IL10) alleles. Results: Assessment of different isotypes of citokines was possible in all cases and confirmed at the second blind-testing. In all of the tested cytokines a prevalent genomic pattern coding for high or low production was observed (70%). Of interest were the findings for IL6 (9/10 high producers), and IL10 (2/10 high producers). Conclusions: 1) polymorphisms of isotypes of IL10, IL6, TNF, IFN, TGF, IL6, and IL10 can be assessed on PBMC-DNA extracted from maternal blood; 2) Significant prevalence of patterns of genomic isotypes coding for high or low production of solubles factors were observed in this first preliminary analysis. Based on these findings, a larger sample is now under investigation including matched controls and newborns data.