IL-10 gene promoter and intron polymorphisms and changes in IL-10 secretion in women with idiopathic recurrent miscarriage.

STUDY QUESTION: Is recurrent pregnancy loss (RPL) associated with polymorphisms in the promoter and intron regions of the interleukin-10 (IL-10) gene? SUMMARY ANSWER: IL-10 rs1518111 was found to be associated with RPL but the commonly studied promoter variants rs1800872, rs1800871 and 1800896 were not. WHAT IS KNOWN ALREADY: Reduced expression of IL-10 is implicated in RPL, due to defective maternal immune tolerance (causing early miscarriages) or placental vascular insufficiency (causing late losses). IL-10 production is in part inherited, and IL-10 gene variants associated with reduced IL-10 expression have been analyzed for their association with RPL, often with inconclusive results. STUDY DESIGN, SIZE, DURATION: A retrospective case-control study was performed between January 2011 and April 2012. The subjects comprised 296 RPL cases and 305 control women. PARTICIPANTS/MATERIALS, SETTING, METHODS: Genotyping of the IL-10 intron (rs1878672, rs3024492, rs1554286, rs1518111, rs3024491, rs3024490) and promoter (rs1800872, rs1800871, rs1800896) variants was done by real-time PCR, with defined clusters. MAIN RESULTS AND THE ROLE OF CHANCE: A higher minor allele frequency (MAF) of rs1518111 (P = 0.03) was in seen RPL cases; but the MAFs of the remaining SNPs were comparable between cases and controls. Setting the homozygous major allele genotype (1/1) as the reference, significantly higher frequencies of heterozygous rs1554286 and rs1800872, and homozygous rs1800896 genotype carriers, and a reduced frequency of homozygous rs1518111 genotype carriers, were seen in RPL cases, while the distribution of the remaining genotypes were comparable between cases and controls. Serum IL-10 levels were significantly reduced in RPL cases compared with control women (P = 0.002), and this correlated with rs1518111 and rs1800871 genotypes in both groups, and with the rs1800872 genotype among control women. A nine-locus (rs1878672, rs3024492, rs1554286, rs1518111, rs3024491, rs3024490, rs1800872, rs1800871 and rs1800896) haploview analysis demonstrated an increased frequency of haplotype 112112121 in RPL cases, thus conferring a disease susceptibility nature to this haplotype. LIMITATIONS, REASONS FOR CAUTION: The main limitation of this study was that it was limited to Bahraini Arabs, thereby necessitating parallel studies of other ethnic groups. Another limitation is the study design, which prompts speculation on whether it is a cause-effect relationship. WIDER IMPLICATIONS OF THE FINDINGS: While the lack of association of the various IL-10 promoter variants with RPL was in agreement with reports from varied ethnic groups, this is the first study to confirm the association between IL-10 rs151811 intronic variant and RPL. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by grants from the Arabian Gulf University Research Fund. None of the authors report any competing interests.

Association of the R67X and W303X non-sense polymorphisms in the protein Z-dependent protease inhibitor gene with idiopathic recurrent miscarriage.

Protein Z-dependent protease inhibitor (ZPI) is a 72 kDa single-chain serpin which inhibits the activated coagulation factors X and XI. Two non-sense polymorphisms of ZPI, R67X and W303X, were recently identified, and were linked with a prothrombotic state. Here, we investigated the association of the R67X (728C>T) and W303X (1438G>A) variants in the ZPI gene with recurrent spontaneous miscarriage (RSM). This was a case-control study involving a total of 288 women with a history of two consecutive or ≥3 non-consecutive pregnancy losses between 8 and 12th week of gestation, along with 304 age-matched and ethnically matched multiparous control women, with no personal or family history of pregnancy complications. The minor allele frequency of R67X (P = 0.003) and W303X (P = 0.014) were higher in RSM cases than in control women. Both single-nucleotide polymorphisms were significantly associated with RSM under the dominant genetic association model, and were in moderate linkage disequilibrium (D' = 0.412; P < 0.001). Taking the common (728)C/(1438)G haplotype as reference, multivariate analysis confirmed the positive association of (728)T/(1438)G [P = 0.043; odds ratio (OR) = 2.25; 95% confidence interval (CI) = 1.03-4.90], and (728)T/(1438)A (P = 0.022; OR = 3.93; 95% CI = 1.23-12.59) haplotypes with increased RSM risk. These differences remained significant after controlling for some covariates. These results demonstrate that both ZPI R67X and W303X non-sense variants and specific ZPI haplotypes are significantly associated with RSM.

Tumor necrosis factor-alpha polymorphisms in women with idiopathic recurrent miscarriage.

We investigated the association of tumor necrosis factor-alpha (TNFalpha) gene polymorphisms with idiopathic recurrent miscarriage (RM). TNFalpha -1031T/C, -863C/A, -857C/T, -376G/A, -308G/A, -238G/A, and +488G/A single nucleotide polymorphisms (SNPs) were investigated in 204 RM women and 248 age-matched parous women by PCR-restriction fragment length polymorphism. Significantly higher frequencies of -1031C and -376A alleles were seen in RM patients; significant differences were also noted in the distribution of -1031T/C, -376G/A, and -238G/A genotypes between case and control subjects. Haploview analysis revealed high linkage disequilibrium between -857C/T and +488G/A SNPs, but was lower between the other polymorphisms. Of the possible 52 seven-locus haplotypes constructed, 10 were common, and were included in subsequent analysis. Increased frequency of CCCGGGG and CCCGGAA haplotypes, and reduced frequency of TCCGGGG and TCCGGGA haplotypes were seen in RM patients than in controls. When the Bonferroni correction was applied, differences were significant for the CCCGGAA haplotype, which was higher (OR=4.14; 95% CI=1.84-8.95), and the TCCGGGA haplotype, which were lower among RM cases (OR=0.09; 95% CI=0.02-0.68), thereby conferring RM susceptibility and protection to these haplotypes, respectively. Multivariate analysis confirmed the positive association of only CCCGGAA haplotype with RM (P=0.010; aOR=2.03; 95% CI=1.18-4.47), after controlling for a number of covariates. These results demonstrate that the TNFalpha polymorphisms, in particular the -1031T/C variant, are significantly associated with idiopathic RM. Additional replication studies on other racial groups are needed to confirm our findings.

Maternal mortality in Bahrain 1987-2004: an audit of causes of avoidable death.

The aim of this report was to establish the national maternal mortality rate in Bahrain over the period 1987-2004, to identify preventable factors in maternal deaths and to make recommendations for safe motherhood. There were 60 maternal deaths out of 243 232 deliveries giving an average maternal mortality rate of 24.7 per 100 000 total births. The main causes of death were sickle-cell disease (25.0%), hypertension (18.3%), embolism (13.3%), haemorrhage (13.3%), heart disease (11.7%), infection (8.3%) and other (10.0%). In an audit of care, 17 (28.3%) out of 60 deaths were judged to be avoidable, nearly half of which were due to a shortage of intensive care beds. We recommend that a confidential enquiry of maternal deaths be conducted at the national level every 3 to 5 years.

Maternal mortality in Bahrain 1987-2004: an audit of causes of avoidable death

The aim of this report was to establish the national maternal mortality rate in Bahrain over the period 1987-2004, to identify preventable factors in maternal deaths and to make recommendations for safe motherhood. There were 60 maternal deaths out of 243 232 deliveries giving an average maternal mortality rate of 24.7 per 100 000 total births. The main causes of death were sickle-cell disease [25.0%], hypertension [18.3%], embolism [13.3%], haemorrhage [13.3%], heart disease [11.7%], infection [8.3%] and other [10.0%]. In an audit of care, 17 [28.3%] out of 60 deaths were judged to be avoidable, nearly half of which were due to a shortage of intensive care beds. We recommend that a confidential enquiry of maternal deaths be conducted at the national level every 3 to 5 years