Evaluation of HLA-G5 Plasmatic Levels During Pregnancy and Relationship with the 14-bp Polymorphism

Problem Plasmatic HLA-G levels increase during pregnancy, but the contribution of each different isoform has not been elucidated yet. Method of study HLA-G5 was analyzed by ELISA in 19 controls, 79 women in the first 8 weeks of pregnancy and in nine women monthly until delivery. Genotyping for the 14-bp polymorphism was performed by PCR amplification of exon 8. Results HLA-G5 was detected in plasma from 80% of pregnant women. The levels did not change during pregnancy, and there were no differences compared to control non-pregnant women. There was a high interindividual variation that was maintained throughout the pregnancy. The presence of +14-bp allele was associated with HLA-G5 positivity. Pregnant women who were heterozygotic to 14-bp polymorphism had significantly higher levels of HLA-G5 compared to -14 bp/-14-bp homozygotic. Conclusion Plasmatic HLA-G5 levels do not change during pregnancy and its concentration depends on 14-bp polymorphism.