The KIR2DL4 receptor and its ligand HLA-G are considered important for fetal-maternal immune tolerance and successful pregnancy. The absence of a particular variant of KIR2DL4 might be a bad prognostic factor for pregnancy outcome. However, it could be compensated by the presence of the respective LILRB1 allele. Therefore, we investigated the KIR2DL4, LILRB1 and HLA-G polymorphisms in 277 couples with spontaneous abortion and 219 control couples by HRM, PCR-SSP and RFLP methods. We found a protective effect of women’s heterozygosity in −716 HLA-G (p = 0.0206) and LILRB1 (p = 0.0131) against spontaneous abortion. Surprisingly, we observed more 9A/10A genotypes of KIR2DL4 gene carriers in the group of male partners from the miscarriage group in comparison to the men from the control group (p = 0.0288). Furthermore, there was no association of women’s KIR2DL4 polymorphism with susceptibility to spontaneous abortion. Multivariate analysis indicated that women’s −716 HLA-G and LILRB1 and men’s KIR2DL4 9A/10A are important in terms of the protection or susceptibility to miscarriage, respectively (p = 0.00968). In conclusion, a woman’s heterozygosity in HLA-G and LILRB1 might be an advantage for a success of reproduction, but the partner’s heterozygosity in 9A/10A KIR2DL4 alleles might not.Electronic supplementary materialThe online version of this article (doi:10.1007/s00005-016-0389-7) contains supplementary material, which is available to authorized users.

IntroductionAn analysis of lead, zinc, cadmium and other trace elements in semen of men from infertile couples was performed to determine the association between abnormal semen parameters and enviromental or occupational exposure to some trace metals.Material and methodsPresence of manganese, cobalt, nickel, copper, zinc, molybdenum, cadmium, tin and lead was measured in seminal plasma of 34 men from infertile couples using spectrometry with time-of-flight analysis. Correlations among sperm parameters and trace metals were determined using cluster analysis and Pearson's correlation coefficient.ResultsAbnormally high concentrations of lead, cadmium, zinc and cobalt were found in 23 seminal plasma of men from infertile couples. The most consistent evidence was determined for an association between high cadmium concentration in seminal plasma and sperm count, motility and morphology below reference limits (p < 0.01). A correlation of significantly increased tin level and reduced sperm count in semen of men with limited fertility potential was observed (p = 0.04).ConclusionsIn our study we observed a correlation of tin level with sperm count in semen of men with limited fertility potential.

The KIR2DL4 gene is characterized by alleles with either 9 or 10 consecutive adenines in exon 7, which encodes the transmembrane domain. The 9A variant produces either a protein with a truncated cytoplasmic tail or one lacking the transmembrane region. This causes a lack of KIR2DL4 expression. In contrast, 10A alleles encode receptors that may be expressed at the cell surface. We tested 438 healthy individuals for polymorphism of the KIR2DL4 gene. KIR2DL4 9A/10A alleles were distinguished by the high resolution melting (HRM) method, and restriction fragment length polymorphism (RFLP) was used for genotyping of three other single nucleotide polymorphisms (SNPs) spanning the near vicinity of the poly-adenine fragment. We found a weak difference between males and females in 9769 C/A genotypes and alleles. In addition, we observed complete linkage disequilibrium (LD) between 9A insertion/deletion in the 9620 position and the 9571T/C position of the gene (r(2)  = 1) both in females and males and almost complete LD with the 9797G/A position (r(2)  = 0.963 for females and r(2)  = 0.892 for males). Most importantly, we detected, in a group of fertile women, a high frequency (30.2%) of homozygosity for the defective 9A variant, which suggests that KIR2DL4 as a functional cell surface receptor is not absolutely necessary for reproduction. On the other hand, lower representation of 10A/10A homozygotes and high frequency of 10A/9A heterozygotes indicates a need for both cell membrane-anchored and soluble KIR2DL4 molecules. Finally, cost-reducing RFLP instead of HRM is proposed for typing 9A and 10A variants.

Almost 1600 individuals from the Polish population were recruited to this study. Among them 319 were fertile couples, 289 were recurrent spontaneous abortion (RSA) couples, and 131 were in the group of recurrent implantation failure (RIF) following in vitro fertilization. The aim of this study was to evaluate the MTHFR c.c.677 C>T and c.c.1298 A>C polymorphisms’ association with RSA and RIF. We used PCR-RFLP with HinfI (677 C>T) and MboII (1298 A>C) digestion. We observed a protective effect of the female AC genotype (OR = 0.64, p = 0.01) and the C allele (AC+CC genotypes; OR = 0.65, p = 0.009) against RSA. Moreover, 1298 AA/677 CT women were more frequent in RSA (31.14%) and RIF (25.20%) groups in comparison to fertile women (22.88%), although this difference was significant only in the case of RSA (p = 0.022, OR = 1.52). Male combined genotype analysis revealed no association with reproductive failure of their partners. Nevertheless, the female/male combination AA/AC of the 1298 polymorphism was more frequent in RSA couples (p = 0.049, OR = 1.49). However, the significant results became insignificant after Bonferroni correction. In addition, analysis of haplotypes showed significantly higher frequency of the C/C haplotype (1298 C/677 C) in the female control group than in the female RSA group (p = 0.03, OR = 0.77). Moreover, the association between elevated homocysteine (Hcy) level in plasma of RSA and RIF women and MTHFR polymorphisms was investigated but did not reveal significant differences. In conclusion, for clinical practice, it is better to check the homocysteine level in plasma and, if the Hcy level is increased, to recommend patients to take folic acid supplements rather than undergo screening of MTHFR for 1298 A>C and 677 C>T polymorphisms.

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