Association Of HLA-C And Their Specific KIR Ligands With Early Unexplained Recurrent Spontaneous Abortion

SECTIONⅠASSOCIATION OF KILLER CELL IMMUNOGLOBULIN-LIKE RECEPTOR GENES AND THEIR EXPRESSION WITH EARLY UNEXPLAINED RECURRENT SPONTANEOUS ABORTIONPART 1 Association of Killer Cell Immunoglobulin-like Receptor Genes in Decdiua and Early Unexplained Recurrent Spontaneous AbortionOBJECTIVES Killer cell immunoglobulin-like receptors(KIR) are expressed on the surface of natural killer(NK) cells and some of T Lymphocytes.NK cell receptors have been suggested have a high-level infiltration with stromal cells and more importantly with invading trophoblast.But their function at the fetomaternal interface remain unknown.To study the relationship between the expression of the susceptiblity to killer-immunoglobulin-like receptors in decidua and early unexplained recurrent spontaneous abortion(URSA). METHODS Decidual samples were obtained from the patients(n=36) who suffered from unexplained recurrent spontaneous abortion and the normal pregnant women(n=34).Specific sequence primer PCR(PCR-SSP) was used to determine the individual KIR genotypes in women experiencing URSA and controls.RESULTS①A higher prevalence of activating KIR genes was seen in patients experiencing URSA than in controls.Among women experiencing URSA,the gene express frequence of KIR2DS1 was more prevalent(60.27%vs 41.18%,P=0.03) compared with controls.②Increased numbers of activating KIR genes was observed in patients with URSA(P=0.041).CONCLUSIONS The increased frequencies of KIR2DS1 may be one of the reasons of URSA.A genetic imbalance between activing and inhibitory KIR genes might confer susceptibility to the occurrence of pregnancy loss.PART 2 Expression of Killer Cell Immunoglobulin-like Receptor Genes in Decdiua and Early Unexplained Recurrent Spontaneous AbortionOBJECTIVES Decidual natural killer(NK) cells express killer cell immunoglobulin-like receptors(KIRs),which bind to ligands on trophoblast cells. This interaction appears to block NK cytotoxicity against trophoblast cells.In this study,we investigated the expression of mRNA of KIRs in decidua of women with early unexplained recurrent spontaneous abortion(URSA).METHODS The decidual samples taken via uterine cucrretting from 36 patients experiencing URSA and 34 healthy controls.The expressions of KIR2DL2,2DL4,3DL1,3DL2 mRNA in decidual tissue were carried out by the RT-PCR.The relative level of KIR2DL1 and 2DL3 mRNA were studied by real time quantitive RT- PCR.RESULTS①The frequencies of inhibitory KIRs mRNA did not differ between women with URSA and normal controls.None of the activating KIRs mRNA was detected.However,there was an decrease in transcripts of KIR2DL2 in women with URSA when compared to normal controls.②The relative level of the KIR2DL1 mRNA did not show significant differences between women with URSA and nomal controls(699.37±259.78 vs 1002.96±476.98,P=0.37).And also no significant differences in KIR2DL3 mRNA was observed between two groups(625.93±234.81 vs 1216.12±425.96,P=0.09).CONCLUSIONS The expression of KIR mRNA may not explain the pathogenesis of URSA.SECTIONⅡASSOCIATION OF HUMAN LEUKOCYTE ANTIGEN-C MOLECULES ON TROPHOBLAST CELLS AND EARLY UNEXPLAINED RECURRENT SPONTANEOUS ABORTIONPART 1 Association of Human Leukocyte Antigen-C Molecules Genes on Trophoblast Cells and Early Unexplained Recurrent Spontaneous AbortionOBJECTIVES To investigate the relationship between the genotype of human leukocyte antigen(HLA)-C molecules on trophoblast cells and early unexplained recurrent spontaneous abortion(URSA).METHODS Trophoblast samples were obtained from the patients(n=36) who suffered from early recurrent spontaneous abortion and the normal pregnant women(n=34).Genotype were detected for HLA-C1 and HLA-C2 by sequence based typing.We used two-tailed Fisher's exact test to compare variables between groups.RESULTS①The haplotype of HLA-C1 showed the highest frequencies in both groups.There was no significant differences in the frequencies of HLA-C1 molecules on trophoblast cells between two groups(66.67%vs 81.03%,P=0.657).But there was higher frequencies of HLA-C2 molecules in the patients than in the controls(33.33%vs 19.07%,P=0.007).②The significant differences were observed in genotype HLA-C1C1(65.52%vs 33.33%,P=0.039) and HLA-C1C2(31.03%vs 66.67%,P=0.001) between control and URSA groups.CONCLUSIONS The increased frequences of HLA-C2 genes were resulted from the imbalance of HLA-C1 and HLA-C2 on the trophoblast cells.The increased frequences of HLA-C2 genes might confer susceptibility to the occurrence of pregnancy loss.PARTⅡAssociation of Human Leukocyte Antigen-C Molecules Expression on Trophoblast Cells and Early Unexplained Recurrent Spontaneous AbortionOBJECTIVES To study the relationship between the expression of the susceptiblity to human leukocyte antigen(HLA)-C molecules on trophoblast cells and early unexplained recurrent spontaneous abortion(URSA).METHODS Trophoblast samples were obtained from the patients(n=36) who suffered from early unexplained recurrent spontaneous abortion and the normal pregnant women(n=34).The level of HLA-C1 mRNA and HLA-C2 mRNA on trophoblast cells were measured by the real time PCR method,and the expression of HLA-C protein was detected by Western immunoblotting method. RESULTS①The relative levels of the HLA-C1 mRNA were significant lower in the patients(59.39±13.43) than in the normal pregnants(95.43±28.78), P=0.016.And the relative levels of the HLA-C2 mRNA did not show differences between two groups(68.22±18.73 vs 48.33±17.30,P=0.321 ).②The expression of HLA-C protein was similar between two groups(1.32±0.19 vs 1.45±0.21,P=0.640).CONCLUSIONS The expression of human leukocyte antigen(HLA)-C1 mRNA on trophoblast cells might confer to the pathogenesis of early unexplained recurrent spontaneous abortion.