Association between polymorphic markers HLA-G and TNF - Alpha and susceptibility to recurrent miscarriages among Bulgarian women

Objective
In order for the pregnancy to be successful, the maternal immune system must accept the semi allogeneic fetus. The presence of 14 base pairs (bp) insertion sequence in the Human leucocyte antigen – G (HLA-G) and the Tumor necrosis factor-alpha (TNF- α) - 308 AA polymorphism could increase the risk for miscarriage.
Materials and methods
To investigate the role of these mutations 50 patients with two or more idiopathic recurrent miscarriages and 50 normal fertile women were tested for the presence of HLA-G 14 bp insertion/deletion and TNF- α -308 G/A variants. Frequencies of the studied polymorphisms were compared among the two groups.
Results
Individuals with a history of miscarriages had a significantly higher prevalence of 14 bp insertion allele compared to control patients (p= 0.04). There was also a two times higher relative risk for a miscarriage among carriers of this variant. No statistical difference in allele frequencies of TNF- α- 308 G/A polymorphism was established between controls and case patients (p= 0.78).
Conclusion
The 14 bp insertion HLA-G variant could be associated with a higher risk for unsuccessful pregnancy according to the results from the study. There is no association between the studied TNF-α 308 GA polymorphism and rate of spontaneous abortions.