Interleukin 1 receptor antagonist polymorphism in women with idiopathic recurrent miscarriage

The Update Immune-Regulatory Role of Pro- and Anti-Inflammatory Cytokines in Recurrent Pregnancy Losses

Recurrent pregnancy losses (RPL) is a common reproductive disorder with various underlying etiologies. In recent years, rapid progress has been made in exploring the immunological mechanisms for RPL. A propensity toward Th2 over Th1 and regulatory T (Treg) over Th17 immune responses may be advantageous for reproductive success. In women with RPL and animals prone to abortion, an inordinate expression of cytokines associated with implantation and early embryo development is present in the endometrium or decidua secreted from immune and non-immune cells. Hence, an adverse cytokine milieu at the maternal-fetal interface assaults immunological tolerance, leading to fetal rejection. Similar to T cells, NK cells can be categorized based on the characteristics of cytokines they secrete. Decidual NK (dNK) cells of RPL patients exhibited an increased NK1/NK2 ratio (IFN-γ/IL-4 producing NK cell ratios), leading to pro-inflammatory cytokine milieu and increased NK cell cytotoxicity. Genetic polymorphism may be the underlying etiologies for Th1 and Th17 propensity since it alters cytokine production. In addition, various hormones participate in cytokine regulations, including progesterone and estrogen, controlling cytokine balance in favor of the Th2 type. Consequently, the intricate regulation of cytokines and hormones may prevent the RPL of immune etiologies. Local or systemic administration of cytokines or their antagonists might help maintain adequate cytokine milieu, favoring Th2 over Th1 response or Treg over Th17 immune response in women with RPL. Herein, we provided an updated comprehensive review regarding the immune-regulatory role of pro- and anti-inflammatory cytokines in RPL. Understanding the roles of cytokines involved in RPL might significantly advance the early diagnosis, monitoring, and treatment of RPL.

Association of of IL-1 receptor antagonist (IL-1RN) and interleukin-1β genes (IL-1β) polymorphisms with recurrent pregnancy loss in Iranian Azeri women

Objective One of the most important problems in human reproduction is recurrent pregnancy loss (RPL). RPL is defined as three or more consecutive abortions in the first trimester of pregnancy. The association between the polymorphisms in the immunological factors and RPL was investigated. The aim of our study was to determine the association of interleukin receptor antagonist (IL-IRN) and interleukin-1β (IL-1β) polymorphisms with RPL in Iranian Azeri women. Materials and methods The study participants consisted of 100 women with RPL of Iranian Azeri origin. The control group comprised 100 age- and ethnically-matched healthy women of the same reproductive age. Genomic DNA was extracted from the whole blood and genotype determinations were performed using polymerase chain reaction (PCR) amplification followed by restriction fragment length polymorphism (RFLP) analysis. Results Our results showed no significant relationship between IL-1RN polymorphism and RPL. The homozygous state in -857 C/T variant was seen to be higher in RPL patients than in control subjects. Also frequency of wild type genotype was lower in RPL patients than in controls. However, this associations was not significant. Conclusion This study suggested that -511 C/T (rs16944) and -31 C/T (rs1143627) polymorphisms in IL-1β gene may not be involved in RPL in Iranian Azeri women. Also the promoter polymorphism of the IL-1RN gene may not play a role in the susceptibility to RPL.

Effects of interleukin-1 receptor antagonist (IL-1Ra) gene 86 bp VNTR polymorphism on recurrent pregnancy loss: a case-control study

Objective

Recurrent pregnancy loss (RPL) is a heterogeneous disease which is defined as two or more consecutive fetal losses during early pregnancy. Interleukin-1 receptor antagonist (

Materials and methods

In this case control study, genetic polymorphism was studied in 140 RPL patients and 140 healthy women as controls. Genomic DNA was extracted from the blood samples and polymorphism analysis was performed using the polymerase chain reaction (PCR) method. Finally, the data obtained were analyzed by statistical software.

Results

We found an increased frequency of the IL-1Ra 1/1 genotype in the case group compared to the control group. Whereas, the frequency of IL-1Ra genotype 1/2 was higher in control group than in the case group. However, we did not observe an association between

Conclusion

VNTR polymorphism may not be a genetic factor for RPL. However, investigation of

Association of interleukin 1 receptor antagonist (IL1RN) gene polymorphism with recurrent pregnancy loss risk in the North Indian Population and a meta-analysis

An appropriate ratio of interleukin 1 beta to interleukin 1 receptor antagonist (IL1Ra) is required for successful pregnancy. Our objective was to study the genetic association between IL1RN variable numbers of tandem repeat (VNTR) polymorphism and recurrent pregnancy loss (RPL). To analyze the association between IL1RN VNTR allele and RPL, we investigated the IL1RN VNTR polymorphism in 136 RPL patients and in 200 healthy control women. Meta-analysis on this polymorphism was conducted to support our findings. PCR based approach was used to analyze IL1RN VNTR polymorphism and it was further confirmed by sequencing. Systematic review and meta-analysis was done using electronic database (Pub-Med, Google Scholar and Ovid) up to February 27, 2013. This meta-analysis was assessed by comprehensive meta-analysis software version 2. For meta-analysis 549 cases and 1,450 controls were included. The frequency of IL1RN genotype 2/2 was significantly higher in RPL compared to control group (AORs 3.10, 95 % CI 1.58-6.11, p = 0.001). The presence of rare allele also increased the risk of RPL significantly (ORs 1.63, 95 % CI 1.16-2.29, p = 0.004). The meta-analysis stratified by ethnicity showed that individuals with allele 2 had increased risk of RPL (OR 1.29, 95 % CI 1.04-1.61, p = 0.01), in Asians population by using fixed model. However the data of the present study clearly suggests that IL1RN VNTR polymorphism is a genetic risk factor for pregnancy loss in the study population.

High risk association of IL-1 receptor antagonist (IL-1RN) VNTR polymorphism with asthma in a North Indian population: a pilot study

BACKGROUND

A pilot case-control study was conducted to evaluate the role of IL-1 receptor antagonist (IL-1RN) VNTR penta-allelic polymorphism in asthma that has been associated with various inflammatory diseases worldwide. This is the first case-control study conducted in India, investigating the role of IL-1RN VNTR polymorphism in asthma pathogenesis.

METHODS

A case-control study was performed with a total of 824 adult subjects, inducting 410 asthma patients and 414 healthy controls from North India. The genotypes were identified by polymerase chain reaction.

RESULTS

Statistical analysis for the IL-1RN VNTR polymorphism revealed that the IL-1RN(*)2 allele was significantly associated with asthma with OR=1.45, 95% CI (1.15-1.85) and p=0.001. The IL-1RN(*)2/2 genotype posed a risk towards asthma with OR=1.66, 95% CI (0.97-2.86) and p=0.048. Most of the phenotypic traits were significantly associated with the disease.

CONCLUSIONS

IL-1RN(*)2 allele is a high risk factor for asthma in the studied North Indian population.

Interleukin-1 gene cluster variants and recurrent pregnancy loss among North Indian women: retrospective study and meta-analysis

The aim of this study was to determine whether or not interleukin-1 alpha (IL-1a), interleukin-1 beta (IL-1b) and IL-1 receptor antagonist (IL-1RA) polymorphisms are associated with risk of unexplained recurrent pregnancy loss (RPL) among North Indian women. This retrospective case–control study examine 200 well-characterized RPL cases for IL-1 gene cluster variants, determined by restriction fragment length polymorphism-PCR. The observed allele, genotype and haplotype distributions were compared with those obtained from 300 ethnically matched negative controls. Invariant distribution of IL-1 gene cluster single-nucleotide polymorphisms was observed among RPL cases and controls. Meta-analysis of IL-1b _511, +3953 and IL-1RN 86-bp variable number tandem repeat from the reported literature and this study did not reveal any significant association with the risk of RPL. In conclusion, no significant difference between RPL and control groups was observed at the allele, genotype or haplotype levels when tested for association using the dominant, recessive and additive models of inheritance for IL-1 gene cluster variants. As far as is known, this is the first report from India pertaining to IL-1 gene cluster variants’ association with the risk of RPL from North India.

Polymorphisms in VEGF, progesterone receptor and IL-1 receptor genes in women with recurrent spontaneous abortion

Hormonal, inflammatory and vascular alterations during pregnancy are thought to be involved in pregnancy loss. The role of progesterone, the actions of which involve cytokines and vascular endothelial growth factor (VEGF), has been thoroughly studied. Genetic factors are involved in modulation of these molecules, and several genes have been associated with recurrent spontaneous abortion (RSA), as well other obstetric conditions. Here we investigate the relationship between RSA and gene polymorphisms of the progesterone receptor (PROGINS), interleukin-1 receptor 1 (PstI) and vascular endothelial growth factor (VEGF) (-634, 936). This case-controlled study comprised a total of 89 women with idiopathic RSA and a control group of 191 women with at least two successful pregnancies and no miscarriages. Genomic DNA was extracted from whole blood, and polymorphism genotyping was conducted by digesting PCR products with specific restriction endonucleases. No correlations were found in any of the investigated polymorphisms, even among dominant, co-dominant and additive inheritance models and alleles. Our results support the hypothesis that these specific gene polymorphisms are not the major determinant of pregnancy success. Although we did not find any correlations, the investigation of these and other polymorphisms remains a challenge in the evaluation of RSA.

Genetic variation in the CYP17 gene and recurrent spontaneous abortions

PURPOSE

The CYP17 gene encodes the enzyme cytochrome P450c17α, which functions at key steps in the synthesis process of human sex steroid hormones. A T/C polymorphism in the 5' promoter region of the CYP17 gene has been described previously. Serum levels of androgens and estrogens have been shown to be elevated in individuals who carry the C substitution (Α2 allele). We hypothesized that variability in genes that control the sex hormone (estrogens, testosterone) biosynthesis might affect the pregnancy outcome. In the present study, we investigated the possible association between the T/C polymorphism of the promoter of CYP17 gene and the risk of recurrent spontaneous abortions in the Greek population.

METHODS

In the prospective case-control study, 148 patients and 134 healthy controls were studied. Women who had at least three unexplained spontaneous abortions before 20 weeks of gestation were included in the patient group. The PCR-RFLP method was used to genotype the subjects.

RESULTS

The frequencies of A1A1, A1A2, A2A2 genotypes were 0.34, 0.52, 0.14, respectively, in the patient group and 0.32, 0.47, 0.21, respectively, in the control group. The allele frequencies were 0.595 and 0.405 for A1 and A2, in the patient group and 0.555 and 0.445 for A1 and A2, respectively, in the control group. The data between the two groups were analyzed by χ(2) test. Our results showed that there are no significant differences in genotype (P = 0.3883) or in allele frequencies (P = 0.3800) between the patient and the control group.

CONCLUSION

The T/C promoter polymorphism of the CYP17 gene is not associated with the risk for recurrent spontaneous abortions in our Caucasian population.

Genetic association of phase I and phase II detoxification genes with recurrent miscarriages among North Indian women

Allelic variants of the detoxification genes that have impaired biotransformation functions may increase susceptibility to reproductive toxicity leading to endometriosis, recurrent miscarriage (RM) or poor pregnancy outcome. In the present study, we have investigated CYP1A1, CYP2D6, GSTT1, GSTP1 and GSTM1, which are involved in the phase I and phase II detoxification systems, in relation to their role in the etiology of unexplained RMs. In a case-control study, we have investigated 200 females with RM and 300 age and ethnically matched healthy controls with successful reproductive history from North India. The frequencies of phase I wild-type genotypes of CYP1A1 and CYP2D6 in RM cases were 0.56 and 0.60, whereas in controls these were 0.68 and 0.65, respectively (both P < 0.05). The GSTM1 null-genotype frequencies were 0.66 and 0.84 among RM cases and controls, respectively, the GSTT1 null-genotype frequencies were 0.52 and 0.45 (P < 0.005) and the GSTP1 variant allele frequencies were 0.23 and 0.20, respectively. In conclusion, we observed significant protective effects of phase I wild-type genotypes and association of the GSTT1 null genotype with RM. Through combined analyses we have highlighted the importance of the balance of phase I/phase II detoxification systems, in the etiology of RM.

Cytokine gene polymorphisms in recurrent spontaneous abortions: a comprehensive review

PROBLEM

Cytokine gene polymorphism studies in women with recurrent spontaneous abortion (RSA) are reviewed to provide comprehensive understanding and a direction for the future investigation.

METHOD OF STUDY

A search of PubMed was made to identify the published data between 2001 and 2007 regarding RSA and cytokine gene polymorphisms.

RESULTS

Either allele and/or genotype frequencies of the following polymorphisms were reported to be significantly different between women with RSA and controls: IFN-gamma +874A-->T, TA (P = 0.01), AA (P = 0.04); IL-6, -634C-->G CG/GG (P = 0.026); IL-10, -592C-->A CC (P = 0.016); IL-1B -511C (P = 0.035), -31T (P = 0.029); IL-1RA, IL1RN*2 (P = 0.002), and IL1RN*3 (P = 0.002). None of these studies was repeatedly reported by others to be significantly different. Among these, four cytokine polymorphisms (IFN-gamma, +874A-->T; IL-1B -511C; IL-1RA, IL1RN*2, IL1RN*3) were refuted by others and rest of them were studied once.

CONCLUSION

Multiple cytokine polymorphisms were reported to be associated with RSA. However, a majority of studies were not confirmed by other investigators or refuted by others. Inconsistent study results might be related to: (i) the production of these cytokines is partly under genetic controls and other factors affect cytokine levels; (ii) ethnic background, environmental factors, and selection criteria for study populations are different and (iii) the possibilities exist that multiple cytokine gene polymorphisms or other genes in linkage disequilibrium may play a role in RSA.

Evidence for association of the G1733A polymorphism of the androgen receptor gene with recurrent spontaneous abortions

OBJECTIVE

To determine whether the G1733A polymorphism of the androgen receptor gene is associated with an increased risk for recurrent spontaneous abortion (RSA).

DESIGN

Case-control study.

SETTING

Division of Genetics and Biotechnology, Department of Biology, University of Athens.

PATIENT(S)

A total of 131 women with at least three unexplained spontaneous abortions before 20 weeks' gestation, with the same partner, composed the study group.

INTERVENTION(S)

Subjects were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method.

MAIN OUTCOME MEASURE(S)

G1733A polymorphism genotypes and allele frequencies.

RESULT(S)

The observed frequencies of GG, GA, and AA genotypes of the G1733A polymorphism were 0.57, 0.27, and 0.16, respectively, for the patient group and 0.76, 0.15, and 0.09, respectively, for the control group. Allele frequencies were 0.70 and 0.84, respectively, for the patient and control groups for the G allele (wild type) and 0.30 and 0.16, respectively, for the patient and control groups for the A allele (mutant). Statistical analysis of these results indicated significant differences between the two groups.

CONCLUSION(S)

These results indicated for the first time that the androgen receptor G1733A polymorphism is strongly associated with increased risk for RSA.

Lack of consistent association between endothelial nitric oxide synthase gene polymorphisms, homocysteine levels and recurrent pregnancy loss in tunisian women

PROBLEM

Polymorphisms of the endothelial nitric oxide synthase (eNOS) gene have been associated with reduced vascular NO production or increased level of homocysteine, and evaluated as risk factors for recurrent pregnancy loss (RPL). Therefore, in this case-control study, we aimed to determine the effects of some eNOS functional polymorphisms: the 27-bp intron 4 repeat, the 894G/T of exon 7, and the promoter substitution -786T/C, in women with RPL.

METHOD OF STUDY

We genotyped 350 patients with RPL and 200 healthy women by polymerase chain reaction (PCR) and restriction fragment length polymorphism-PCR (RFLP-PCR). The homocysteine total plasma concentrations (tHcy) were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

None of the eNOS polymorphisms-related alleles, genotypes, and haplotypes were associated with RPL. The tHcy were similar between patients and controls; no significant association between tHcy levels and eNOS genotypes could be evidenced.

CONCLUSION

The present study identified a lack of association between eNOS gene polymorphisms, the risk of RPL and tHcy levels.

Interleukin-1 receptor antagonist gene (IL-1RN) polymorphism is a predictive factor of clinical pregnancy after IVF

BACKGROUND

Only 25% of IVF transfer cycles lead to a clinical pregnancy, calling for continued technical progress but also more in depth analysis of patients' individual characteristics. The interleukin-1 (IL-1) system and matrix metalloproteinases (MMPs) are strongly implicated in embryo implantation. The genes coding for IL-1Ra (gene symbol IL-1RN), IL-1beta, MMP2 and MMP9 bear functional polymorphisms. We analysed the maternal genetic profile at these polymorphic sites in IVF patients, to determine possible correlations with IVF outcome.

METHODS

One hundred and sixty women undergoing an IVF cycle were enrolled and a buccal smear was obtained. The presence of IL-1RN variable number of tandem repeats and IL-1B + 3953, MMP2-1306 and MMP9-1562 single nucleotide substitutions were determined. Patients were divided into pregnancy failures (119), biochemical pregnancies (8) and clinical pregnancies (33).

RESULTS

There was a 40% decrease in IL-1RN*2 allele frequency (P = 0.024) and a 45% decrease in IL-1RN*2 carrier status in the clinical pregnancy group as compared to the pregnancy failure group (P = 0.017). This decrease was still statistically significant after a multivariate logistic regression analysis. The likelihood of a clinical pregnancy was decreased accordingly in IL-1RN*2 carriers: odds ratio = 0.349, 95% confidence interval = 0.2-0.8, P = 0.017. The IL-1B, MMP2 and MMP9 polymorphisms showed no correlation with IVF outcome.

CONCLUSIONS

IL-1RN*2 allele carriage is associated with a poor prognosis of achieving a pregnancy after IVF.

Dysplasia: a review

Bronchopulmonary dysplasia (BPD) is a common perinatal complication of very low birth weight preterm infants with a significant risk of long-term disability and morbidity. While clinical conditions such as prematurity and mechanical ventilation are its major risk factors, studies suggest that there is an individual susceptibility to BPD. This comprehensive review summarizes data collected about the implication of genetic polymorphisms in BPD and in its risk factors. Some studies have directly related the risk of BPD to genotype. Indeed, carrier states of genetic variants of cytokines (IFNgamma T+874A), adhesion molecules (L-selectin-Pro213Ser), elements of renin-angiotensin system (ACE-I/D), antioxidant enzymes (GST-P1 Val105Ile), and surfactant proteins (SPA1, SPB intron 4) has been identified as risk factors to BPD. Other studies investigated the role of genotype in BPD risk factors. Premature birth has been linked to carrier states of genetic variants with an impact on immune status (such as IL-6 G(-174)C, MBL2 54G/A, VEGF G+405C, HSP72 A+1267G genes) and matrix metalloproteases. Fetal inflammatory response syndrome, a major determinant of BPD is also affected by genotype (including LTalpha A+250G). Disturbed intrauterine lung development and vascularization may also contribute to BPD; these processes may be impaired in the presence of some rare genetic mutations. Furthermore, there is also a genetic component in the susceptibility to other perinatal adaptational disturbances such as respiratory distress syndrome that are associated with an increased need for mechanical ventilation, and, hence, with lung damage. The genetic variants presented in this article may help to identify infants at risk for BPD.

Pregnancy-associated plasma protein-A polymorphism and the risk of recurrent pregnancy loss

Pregnancy-associated plasma protein-A (PAPP-A)/insulin-like growth factor-binding protein-4 (IGFBP4) protease is a member of the metzincin family of metalloproteases, known as a sensitive biomarker of adverse pregnancy outcomes. Recently, a missense A/C (Tyr/Ser) polymorphism (dbSNP: rs7020782) in the PAPPA gene has been reported. To examine the association between recurrent pregnancy loss (RPL) and this polymorphism, a case-control study of 215 cases with two or more pregnancy losses (PLs) and 420 fertile controls was performed. Genotyping of the PAPPA polymorphism was determined by allelic discrimination using fluorogenic probes and the 5' nuclease assay. Sixty-nine cases (32.1%) were heterozygous and 11 cases (5.1%) were homozygous for the C allele of PAPPA; the respective figures were 127 (30.2%) and 11 (2.6%) in the controls. Women carrying the C allele had a tendency to increased risk of RPL (AA genotype [reference]; AC genotype: odds ratio [OR], 1.17; 95% confidence interval [CI], 0.82-1.68; CC genotype: OR, 2.06; 95% CI, 0.87-4.90), but it was not significant. Women with three or more PLs had a similar tendency (AA genotype [reference]; AC genotype: OR, 1.04; 95% CI, 0.66-1.64; CC genotype: OR, 2.20; 95% CI, 0.82-5.91). The risk of RPL with at least one PL after 9 weeks' gestation significantly increased in women carrying the C allele (AA genotype [reference]; AC genotype: OR, 1.54; 95% CI, 0.95-2.49; CC genotype: OR, 2.83; 95% CI, 1.00-8.05; AC+CC genotypes: OR, 1.65; CI, 1.04-2.62). This is the first report on the PAPPA gene polymorphism in women with RPL, demonstrating some association between the investigated polymorphism and the risk of RPL.

A polymorphism of the interleukin 1 receptor antagonist is not associated with polycystic ovary syndrome in Caucasian women

In a prospective case-control study we investigated the association of a common polymorphism of the interleukin 1 receptor antagonist gene (IL-1 RA) with the occurrence and the clinical characteristics of polycystic ovary syndrome (PCOS). Allele frequencies did not vary statistically significantly among women with PCOS and healthy controls or within the PCOS group with respect to their clinical characteristics.

Interleukin-1 receptor antagonist and interleukin-1 beta polymorphisms in women with recurrent miscarriage

Genotypes and allele distributions for the interleukin (IL)-1beta -511 C/T and the IL-1 receptor antagonist gene intron 2 tandem repeat polymorphisms were compared in 206 women with recurrent miscarriage and a control population. No significant differences were observed between the distributions of IL-1beta or IL-1 receptor antagonist gene alleles in either the recurrent miscarriage group as a whole or when divided according to the cause of recurrent miscarriage compared with controls, which suggests that variation in the IL-1 receptor antagonist gene and IL-1beta genes individually does not play a role in susceptibility to recurrent miscarriage.

Caffeine intake, CYP1A2 polymorphism and the risk of recurrent pregnancy loss

Some case-control studies have demonstrated that caffeine intake and high CYP1A2 activity increase risks of recurrent pregnancy loss (RPL) but the multifactorial effect is obscure. To investigate whether susceptible women who have more caffeine intake are at high risk of RPL, a case-control study of 58 cases with two or more RPL and fertile 147 controls was performed. The association between daily caffeine intake together with CYP1A21F (AA versus CA and CC) genotype and RPL was assessed. Without consideration of the genotype, there were no significant differences of the RPL risk in proportion to daily caffeine intake [less than 100 mg (reference); 100-299 mg: odds ratio (OR), 1.29; 95% confidence interval (CI), 0.66-2.50; 300 mg or more: OR, 1.82; 95% CI, 0.72-4.58; P for trend, 0.20]. However, the RPL risk significantly increased only among women who had homozygous CYP1A21F alleles with a dosage effect of daily caffeine intake [less than 100 mg (reference); 100-299 mg: OR, 1.94; 95% CI, 0.57-6.66; 300 mg or more: OR, 5.23; 95% CI, 1.05-25.9; P for trend, 0.03]. It was demonstrated for the first time that an increase in caffeine intake deteriorates the fecundity among susceptible women.

Polymorphisms within the interleukin-1 gene family and unexplained late intrauterine fetal death: a multi-center study

PROBLEM

Interleukin-1 (IL-1) mediated inflammatory processes have been proposed to be involved in the pathogenesis of late unexplained intrauterine fetal death (IUFD). We determined whether common polymorphisms within the IL-1 gene locus can serve as candidate genes for this condition.

METHOD OF STUDY

In a multi-center case-control study, we evaluated the -889 C/T polymorphism of the IL-1alpha gene (IL1A), the -511 C/T polymorphism of the IL-1beta promoter (IL1B promoter), the +3953 C/T polymorphism of IL-1beta exon 5 (IL1B exon 5), and a 86 base pair repeat in intron 2 of the IL-1 receptor antagonist gene (IL1RN) in 94 women with IUFD and 94 healthy controls using pyrosequencing.

RESULTS

No significant associations were found between the presence of polymorphic alleles of IL1A (P = 0.9), IL1B promoter (P = 0.3), IL1B exon 5 (P = 0.9), and IL1RN intron 2 (P = 0.7) and the incidence of IUFD. In women with IUFD, polymorphisms were not associated with the timing of fetal death and birth weight.

CONCLUSIONS

Polymorphisms within the IL1 gene family are not associated with the occurrence of IUFD overall and do not modulate the clinical characteristics of affected pregnancies in a large series of Caucasian women.

Genetic polymorphisms and risk for acute renal failure in preterm neonates

Acute renal failure (ARF) affects about 10% of severely ill neonates. Recent studies have shown that genetic polymorphisms of proteins that play a role in neonatal physiology may contribute to individual susceptibility to both ARF and its risk factors. Our review summarizes the data collected to date. Studies have shown that the risk of preterm neonates for ARF is directly associated with a combination of high tumor necrosis factor-alpha producer and low interleukin-6 producer genotypes, as well as with low heat shock protein 72 producer genotype. Premature birth is itself the most important risk factor for a number of complications, including ARF, and recent studies have also shown an association between several maternal and fetal cytokine genetic polymorphisms and increased inflammatory response in preterm neonates. These polymorphisms could also be associated with increased risk for disorders such as sepsis and necrotizing enterocolitis, which lead to renal hypoperfusion and ARF. Genetic polymorphisms of the renin-angiotensin-aldosterone system have not been shown to directly influence risk for ARF. They may, however, be associated with patent ductus arteriosus, poor postnatal adaptation, and heart failure, which are all prevalent risk factors for ARF.

Fetal interleukin-1 receptor antagonist gene polymorphism, intra-amniotic interleukin-1beta levels, and history of spontaneous abortion

OBJECTIVE

The purpose of this study was to determine whether fetal carriage of specific alleles of the polymorphic interleukin-1 receptor antagonist gene is associated with variations in intra-amniotic cytokine levels and previous pregnancy outcomes.

STUDY DESIGN

Fetal cells in midtrimester amniotic fluid from 189 women were tested for interleukin-1 receptor antagonist intron 2 length polymorphisms. Concentrations of cytokines in amniotic fluid were tested by enzyme-linked immunosorbent assay. Pregnancy history data were obtained subsequently.

RESULTS

Homozygosity for interleukin-1 receptor antagonist allele 1 was detected in 13 of 17 fetuses (76.5%) from women whose previous pregnancies all ended in spontaneous abortions, as compared with 33 of 74 fetuses (44.6%) from women with at least 1 previous term birth ( P = .02). Fetal carriage of interleukin-1 receptor antagonist allele 2 was associated with only 1 (5.9%) previous spontaneous abortion, as opposed to 31 pregnancies (41.9%) that were associated with a previous term delivery ( P = .004). A similar relationship between interleukin-1 receptor antagonist allele 1 and spontaneous abortions was observed when pregnancies of white women only were analyzed. Median mid trimester amniotic fluid interleukin-1beta concentrations were higher in women whose previous pregnancies ended in term deliveries (15.7 pg/mL), as opposed to women with 1 to 2 (6.4 pg/mL; P = .04) or > or =3 (4.1 pg/mL; P = .007) previous spontaneous abortions. Fetal carriage of interleukin-1 receptor antagonist allele 2 was associated with elevated intra-amniotic interleukin-1beta levels (16.2 pg/mL), as compared with interleukin-1 receptor antagonist allele 1 homozygotes (10.8 pg/mL; P = .03).

CONCLUSION

Fetal carriage of interleukin-1 receptor antagonist allele 1 is associated with reduced intra-amniotic interleukin-1beta concentrations and an increased occurrence of spontaneous abortions in previous pregnancies.

Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss

The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.

Interleukin-1 receptor antagonist gene polymorphism is associated with increased risk of epithelial ovarian cancer

BACKGROUND

Different studies indicate that immunological components play a key role in the development of cancer. Interleukin-1 (IL-1) is known to be critically involved in ovarian carcinogenesis and in other solid tumors. Therefore, we investigated the possible influence of the polymorphism of the IL-1 receptor antagonist (IL-1 RA) genes on the development of ovarian cancer.

PATIENTS AND METHODS

In a prospective study we analyzed the polymorphism of the IL-1 RA gene in 108 women with ovarian cancer compared with 112 patients with benign gynecological diseases. Genomic DNA fragments were amplified by PCR.

RESULTS

The distribution of genotype frequencies was significantly different between the study and control group with respect to allele 1/2 heterozygotes (32.4% versus 15.2%; P = 0.004). Patients who were heterozygous at allele 2 for IL-1 RA (IL-RA 1/2) had a significantly higher risk of ovarian cancer with a calculated odds ratio of 2.7 (95% confidence interval 1.4-5.2). There were no differences between IL-1 RA 1/2 polymorphism and all other alleles in tumor stage (International Federation of Gynecology and Obstetrics), histological type, grading, postoperative tumor volume, volume of ascites, recurrence status or age.

CONCLUSIONS

The allele 2 polymorphism of the IL-1 RA gene seems to play a role in the occurrence of ovarian cancer and should be investigated for screening and risk evaluation.

A polymorphism of the interleukin-1 receptor antagonist plays a prominent role within the interleukin-1 gene cluster in vulvar carcinogenesis

OBJECTIVE

The interleukin-1 (IL-1) family, that is, IL-1alpha and beta and the IL-1 receptor antagonist (IL-1RA), is known to modulate various tumorigenic and tumoricidal effects in humans. Its biological function in squamous cell carcinogenesis of various anatomical sites has been stressed. Although various studies showed a certain association between genes encoding the IL-1 family and human malignancies, no data with respect to vulvar cancer have been published to date.

METHODS

We ascertained four polymorphisms of the IL-1alpha gene (IL1A C[-889]T), the IL-1beta gene (IL1B promoter C[-511]T and IL1B exon 5 position +3953), and the IL-1RA gene (IL1RN intron 2) in 68 patients with surgically treated squamous cell vulvar cancer and 228 healthy Caucasian controls.

RESULTS

Presence of the minor allele of the IL1RN polymorphism was found to be protective for vulvar cancer [odds ratio (OR)=0.5, P=0.03], the other investigated polymorphisms showed no association with the disease and the investigated clinicopathological parameters. In a multivariate analysis, only the established prognosticators were associated with patients' survival.

CONCLUSION

We are the first to report on polymorphisms in genes encoding cytokines in patients with vulvar cancer. Reflecting its biological role, the common IL1RN intron 2 polymorphism seems to play a prominent role within the IL-1 gene cluster with respect to vulvar carcinogenesis.

The matrix metalloproteinase system: changes, regulation, and impact throughout the ovarian and uterine reproductive cycle

The ovary and uterus undergo extensive tissue remodeling throughout each reproductive cycle. This remodeling of the extracellular environment is dependent upon the cyclic hormonal changes associated with each estrous or menstrual cycle. In the ovary, tissue remodeling is requisite for growth and expansion of the follicle, breakdown of the follicular wall during the ovulatory process, transformation of the postovulatory follicle into the corpus luteum, as well as the structural dissolution of the corpus luteum during luteal regression. In the uterus, there is extraordinary turnover of the endometrial connective tissue matrix during each menstrual cycle. This turnover encompasses the complete breakdown and loss of this layer, followed by its subsequent regrowth. With implantation, extensive remodeling of the uterus occurs to support placentation. These dynamic changes in the ovarian and uterine extracellular architecture are regulated, in part, by the matrix metalloproteinase (MMP) system. The MMP system acts to control connective tissue remodeling processes throughout the body and is comprised of both a proteolytic component, the MMPs, and a regulatory component, the associated tissue inhibitors of metalloproteinases. The current review will highlight the key features of the MMPs and tissue inhibitors of metalloproteinases, focus on the changes and regulation of the MMP system that take place throughout the estrous and menstrual cycles, and address the impact of the dynamic tissue remodeling processes on ovarian and uterine physiology.

IL-1 receptor antagonist gene polymorphism in recurrent spontaneous abortion

Genetic factors may contribute to the development of an aberrant pro-inflammatory immune response during pregnancy, thereby increasing the risk of some pregnancy-related pathologies such as recurrent spontaneous abortion (RSA). Interleukin 1 receptor antagonist is an important anti-inflammatory molecule encoded by the IL1RN gene, in which an intronic polymorphism has been described. Even though the molecular genetic mechanisms are not understood, this non-coding polymorphism, and especially IL1RN*2, has been associated with several chronic inflammatory and autoimmune diseases. IL1RN*2 is also associated with increased activity of IL-1beta, which is an important pro-inflammatory cytokine. We investigated the genetic variants of IL1RN in 37 Finnish women with RSA and 800 randomly selected Finnish blood donors. The women with RSA showed a significantly increased frequency of genotypes bearing the rare allele IL1RN*3 compared to the blood donors (10.8 vs 2.1%, odds ratio 5.6, 95% CI: 1.5-19.0, P=0.006). Our results suggest that IL1RN polymorphisms may predispose to RSA in a small subgroup of patients.

The balance between IL-1 and IL-1Ra in disease

IL-1 is an important mediator of inflammation and tissue damage in multiple organs, both in experimental animal models of disease and in human diseases. The IL-1 family consists of two agonists, IL-1alpha and IL-1beta, two receptors, biologically active IL-1RI and inert IL-1RII, and a specific receptor antagonist, IL-1Ra. The balance between IL-1 and IL-1Ra in local tissues plays an important role in the susceptibility to and severity of many diseases. An allelic polymorphism in the IL-1Ra gene has been associated with a variety of human diseases primarily of epithelial and endothelial cell origin. This association may be secondary to an imbalance in the IL-1 system with enhanced production of IL-1beta and reduced production of the major intracellular isoform of IL-1Ra. Treatment of RA with daily subcutaneous injections of recombinant IL-1Ra protein has been shown to be efficacious. Gene therapy approaches with IL-1Ra are being evaluated for the treatment of RA and other human diseases.

T helper 1-type immunity to trophoblast antigens in women with a history of recurrent pregnancy loss is associated with polymorphism of the IL1B promoter region

Recurrent pregnancy loss (RPL) is a common disorder during early gestation. Recent evidence suggests that T helper 1 (Th1)-type immunity is associated with unsuccessful pregnancy especially in women with RPL of otherwise unknown etiology, while Th2-type immunity is associated with pregnancy success. Interleukin (IL)-1 may influence Th1/Th2 immune responsiveness and has been implicated in the establishment of successful pregnancy. In the present study, we investigated polymorphism of the IL-1beta gene (IL1B) in women with a history of RPL. Significant increases in the frequencies of IL1B promoter region variants IL1-511C and IL1B-31T were found in women with a history of RPL. Increased frequencies of these two variants and their homozygotes were found only in cases having evidence of Th1 immunity to trophoblast as determined by IFN-gamma production of peripheral blood mononuclear cells (PBMCs) stimulated with a trophoblast cell-line extract. Significantly higher IFN-gamma production by PBMCs in response to trophoblast correlated with variant IL1B-511C and its homozygocity in women with RPL. These results suggest that variants -511C and -31T in the IL1B promoter region confer risk for RPL associated with Th1 immunity to trophoblast antigens.