The Distinctive Variation in Killer Cell Immunoglobulin-like Receptor Genotypes in Patients with Unexplained Recurrent Spontaneous Abortions

OBJECTIVE: To investigate whether patients with unexplained recurrent spontaneous abortions (URSAs) have specific killer cell immunoglobulin-like receptor (KIR) genotype profiles. STUDY DESIGN: A total of 95 childless women with URSAs and 111 randomly selected healthy women as control subjects were genotyped for 15 selected KIR genes using polymerase chain reaction of sequence-specific primers (PCR-SSP). RESULTS: The KIR2DL5 (p= 0.002), KIR2DS2 (p= 0.007), and KIR2DS1 (p= 0.005) gene frequencies were significantly higher in the URSA group than in the control group. We identified 49 KIR genotype profiles, 19 of which have never previously been described. The genotype frequency indicated that the most frequently found genes included 8 genes in the control group (20.72%) and 14 genes in the patient group (14.74%). The frequency of genotype 2DL1(+), 2DL2(+), 2DL3(+), 2DL4(+), 2DL5(+), 3DL1(+,) 3DL2(+), 3DL3(+), 2DS1(+), 2DS2(+), 2DS3(+), 2DS4(+), 2DS5(+), 3DS1(+), KIR2DP1(+) was significantly higher in the URSA patients than in the control subjects (11.58% in URSA vs. 1.80% in controls; p= 0.007). CONCLUSION: The results showed that the distinctive variation in the KIR genotype in women might be associated with susceptibility to URSA.