Autoimmunity and reproductive failure

Killer cell immunoglobulin-like receptors (KIR) and human leukocyte antigen-C (HLA-C) allorecognition patterns in women with endometriosis

Endometriosis shares similarities with several autoimmune diseases. The human leukocyte antigen (HLA)-C genotype is associated with several human autoimmune diseases. HLA-C is a ligand of killer cell immunoglobulin receptors (KIRs) and is an essential regulator of natural killer cell activity, which is associated with endometriosis progression. Polymorphisms in HLA-C and KIR affect the activity of NK cells and susceptibility to several diseases. Therefore, we attempted to investigate an association between HLA-C genotype and KIR polymorphism and the occurrence of endometriosis. We tested the association of certain KIR and HLA-C combinations and the development of endometriosis by characterizing both KIR and HLA-C genes in 147 women with endometriosis and 117 controls. The HLA-C genotypes and KIR polymorphisms were analyzed via DNA-based method for higher-resolution genotyping. We found that the occurrence of HLA-C*03:03*01 was increased in endometriosis than in control groups. Analysis of various KIR haplotypes revealed differences between the endometriosis and control cohorts. The number of KIR centromeric A/A haplotypes was increased in the endometriosis group than controls. Moreover, the endometriosis cohort was characterized by reduced number of KIR2DS2-positive individuals in the Han Chinese population. Our current findings suggest that the KIR and HLA-C genotypes are associated with the pathogenesis of endometriosis.

Association of HLA class I and class II alleles with susceptibility to endometriosis

Although the exact etiology of endometriosis is unclear, several lines of evidence support roles for both cell-mediated and humoral immunity in its pathogenesis. To assess the association between HLA genotypes and endometriosis, we investigated the frequencies of HLA-A, -B, -C, and -DRB1 antigens or alleles in 123 Japanese patients with endometriosis and 165 healthy women as controls. Significant positive association with endometriosis was observed for HLA-B7 (OR = 2.7, 95% CI = 1.5-5.1, p(u) = 0.0022, p(c) = 0.0440) and for Cw*0702 (OR = 2.1, 95% CI = 1.2-3.3, p(u) = 0.0026, p(c) = 0.0398). An increased frequency of DRB1*0101 was observed in endometriosis patients compared with control subjects (OR = 2.3, 95% CI = 1.2-4.4, p(u) = 0.0143), but was not statistically significant after correction for multiple comparisons. Two-locus analysis indicated that the susceptibility to endometriosis was primarily associated with B7, and that the increased frequencies of Cw*0702 and DRB1*0101 in patients reflected the linkage disequilibrium between B7 and Cw*0702 and DRB1*0101. Most of the B7 antigens were encoded by the B*0702 allele, which was in complete linkage disequilibrium with A24, Cw*0702, and DRB1*0101. Therefore, our results indicated that the HLA-A24-B*0702-Cw*0702-DRB1*0101 haplotype was associated with endometriosis susceptibility. Our findings may provide an important clue to elucidating the pathogenesis of endometriosis.

Genetic contribution of the interleukin-10 promoter polymorphism in endometriosis susceptibility

PROBLEM

Interleukin-10 (IL-10) is an important immunomodulatory cytokine. The aim of this study was to investigate whether polymorphisms of the IL-10 gene promoter polymorphisms may be responsible in part for genetic susceptibility to endometriosis.

METHODS OF STUDY

Polymorphisms at position -1082 and -592 in the IL-10 promoter region were determined in 196 patients with endometriosis and 160 fertile healthy women by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).

RESULTS

There were no statistically significant differences in the genotype and allele frequencies of IL-10 promoter polymorphism between the endometriosis and control groups. However, when subgrouped according to clinical features, the frequencies of the -592*CC genotype and -592*C allele were significantly increased in patients with autoantibodies to carbonic anhydrase II (anti-CA II ab) compared with controls.

CONCLUSION

IL-10 promoter polymorphisms were associated with the production of anti-CA II ab in patients with endometriosis, suggesting a role in the genetic susceptibility for endometriosis.

Autoantibody screening for infertility: explaining the unexplained?

Several laboratories currently offer panels of serum autoantibody assays to screen women with unexplained infertility and those undergoing in vitro fertilization (IVF). Offering these tests implies that they have predictive value for the outcome of proposed infertility treatments such that the results of the testing would alter clinical management. Because screening for antiphospholipid antibodies adds expense to already costly procedures, it is an appropriate time to review the justification for the use of these panels.