Association of cytotoxic T-lymphocyte-associated protein 4 polymorphisms with recurrent pregnancy loss: A case-control study

BACKGROUND: A large proportion of cases of recurrent pregnancy loss (RPL) are associated with immunological factors. OBJECTIVE: This study investigated the association between single nucleotide polymorphisms of cytotoxic T-lymphocyte-associated protein (CTLA)-4 gene in women with a history of RPL compared to healthy women. MATERIALS AND METHODS: A case-control study was performed on 2 groups consisting of 120 healthy women with no history of abortion and at least one delivery (control) and 120 women with a history of 2 or more primary RPLs (case). In addition, 5 mL of peripheral blood sample was taken from all subjects. The frequencies of CTLA-4 rs3087243 and rs231775 polymorphisms were assayed by restriction fragment length polymorphism polymerase chain reaction and rs5742909 using the high-resolution melting real-time polymerase chain reaction method. RESULTS: The mean age of the women in the control and RPL groups were 30.03 ± 4.23 (range 21-37), and 28.64 ± 3.61 yr (range 20-35), respectively. Pregnancy loss numbers ranged between 2-6 in women with a history of RPL, and between 1 and 4 in the successful pregnancy group. Statistical analysis showed a significant difference between the genotypes of GG and AG in the 2 groups in rs3087243 polymorphism (OR 1.00 for GG genotype and OR 2.87 for AG genotype, p = 0.0043). No significant difference was observed in the genotype frequencies of rs231775 and rs5742909 polymorphisms, of the 2 groups (p = 0.37, and p = 0.095), respectively. CONCLUSION: Our findings indicated that CTLA-4 polymorphism, rs3087243, might be associated with a risk of RPL in Iranian women.