Interleukin-6 level and gene polymorphism in spontaneous miscarriage

No Association of Polymorphisms in the Genes Encoding Interleukin-6 and Interleukin-6 Receptor Subunit Alpha with the Risk of Keloids in Polish Patients

A keloid is a benign fibroproliferative hypertrophy of scar tissue that extends outside the original wound and invades adjacent healthy skin. Keloid formation is thought to be a complex process including overactivity of the interleukin-6 signaling pathway and genetic susceptibility. The aim of the study was to investigate possible associations between rs1800797, rs1800796, and rs1800795 polymorphisms in the promoter of the IL6 gene encoding interleukin-6 and the rs2228145 polymorphism in the IL6R gene encoding the interleukin-6 receptor subunit alpha with the predisposition to keloids in Polish patients. The genetic polymorphisms were identified either using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) or sequencing of samples of genomic DNA extracted from blood leukocytes of 86 adult patients with keloids and 100 newborns comprising a control group. No significant differences in the distributions of IL6 or IL6R alleles or genotypes were found between keloid patients and newborn controls. There were also no significant differences between both groups in the distribution of IL6 haplotypes. The IL6 rs1800797, rs1800796 and rs1800795 and IL6R rs2228145 polymorphisms were not found to predispose individuals in the study group to keloids. IL6 promoter haplotypes were not found to be associated with a higher risk of keloids in the studied group.

Analysis of histopathology and changes of major cytokines in the lesions caused by Mycoplasma ovipneumoniae infection

BACKGROUND

Mycoplasma ovipneumoniae (M. ovipneumoniae) is one of the main pathogens of sheep pneumonia, causing a series of clinical symptoms, such as depression, anorexia, hyperthermia, cough, dyspnea, and tract secretions. In recent years, the prevalence of M. ovipneumoniae pneumonia has become increasingly serious in sheep farms in Ningxia, China, leading to the death of sheep, and causing significant economic losses. In this study, the pathological organs infected by M. ovipneumoniae were collected to observe histopathological change, to determine the tissue localization of M. ovipneumoniae, and to analyze the cytokine changes, which lays a basis for the diagnosis and pathogenesis of M. ovipneumoniae disease.

RESULTS

In this study, M. ovipneumoniae was detected in 97 of 105 samples collected from 13 large-scale sheep farms for nucleic acid by PCR. One representative isolate per farm was isolated from 13 farms. The lesions caused by M. ovipneumoniae were mainly in the trachea, bronchus, and lung, including necrosis of tracheal mucosal epithelial cells, disintegration of some epithelial cells, edema of mucosal lamina propria, with inflammatory cell infiltration, cytoplasmic vacuolization of epithelial cells of bronchial mucosa, massive infiltration of inflammatory cells in the alveolar space of lung, necrosis and hyperplasia of alveolar epithelial cells. Immunohistochemical analysis showed that the proportion of M. ovipneumoniae positive area in the lung was the largest, followed by that in the bronchus and trachea. Compared to healthy animals, diseased animals exhibited up-regulated gene expression levels of IL-1β, IL-6, and NF-κB in the trachea, bronchus, and lungs. In contrast, the expression of IL-10, IL-12, and IFN-γ was primarily limited to the trachea and bronchus. The expression of IL-1β showed differential patterns across different lung regions, with variations observed among lung lobes. Additionally, other cytokines consistently showed significant up-regulation specifically in the bronchus.

CONCLUSIONS

M. ovipneumoniae is primarily found in the lungs of infected individuals. NF-κB, an essential transcription factor, is involved in the regulation of IL-1β transcription. IL-12 may enhance the cytotoxic function of natural killer cells during M. ovipneumoniae infection. Those findings demonstrate the distinct expression profiles of cytokines in various anatomical sites throughout disease progression, suggesting the potential role of bronchial tissue as a major site of immune response.

IL-6 and IL-8: An Overview of Their Roles in Healthy and Pathological Pregnancies

Interleukin-6 (IL-6) is an acknowledged inflammatory cytokine with a pleiotropic action, mediating innate and adaptive immunity and multiple physiological processes, including protective and regenerative ones. IL-8 is a pro-inflammatory CXC chemokine with a primary function in attracting and activating neutrophils, but also implicated in a variety of other cellular processes. These two ILs are abundantly expressed at the feto-maternal interface over the course of a pregnancy and have been shown to participate in numerous pregnancy-related events. In this review, we summarize the literature data regarding their role in healthy and pathological pregnancies. The general information related to IL-6 and IL-8 functions is followed by an overview of their overall expression in cycling endometrium and at the feto-maternal interface. Further, we provide an overview of their involvement in pregnancy establishment and parturition. Finally, the implication of IL-6 and IL-8 in pregnancy-associated pathological conditions, such as pregnancy loss, preeclampsia, gestational diabetes mellitus and infection/inflammation is discussed.

Cross-sectional study of chromosomal aberrations and immunologic factors in Iraqi couples with recurrent pregnancy loss

BACKGROUND

Parental chromosomal aberrations are important causes of recurrent pregnancy loss (RPL). Some immunological factors such as antiphospholipid antibodies and interleukin-6 (IL-6) also contribute to this complication. The aim of this study was to determine the frequency of chromosomal abnormalities and to evaluate some of the immunological factors in couples with RPL from different cities in Iraq.

METHODS

This study was conducted on 25 couples (50 individuals) who had more than two first trimester abortions in the past and 25 healthy females as controls. Karyotyping was performed on peripheral blood of all participants. Anticardiolipin (IgG and IgM), antiphosopholipid (IgG and IgM), lupus anticoagulant, and IL-6 were assayed. Data were analyzed using appropriate statistical tests.

RESULTS

Chromosomal abnormalities were found in 28.0% (n = 7/25) of RPL couples. Of these five (10.0%) were female and two (4.0%) were male. The types of structural abnormalities were as follows: 45, XX, t(21; 21); 45, XX, rob (14, 15); 46, XX, add (21) (p13); 46 XY, add (21)(p13); 46, XX, 21ps+; 46, XY, per inv (9) (p11q12) and 45, XX, t(13q, 13q). No chromosomal abnormalities were found in the control group. Also, no significant differences were found in the immunological parameters of the couples with RPL and the control group.

CONCLUSION

In this study, karyotyping revealed a high number of chromosomal abnormalities associated with the RPL in Iraqi couples. Since identification of genetic causes of miscarriage is important for genetic counseling and educating couples about the risk of future pregnancies, it is recommended that conventional karyotyping be investigated in patients with RPL.

Maternal Serum Cytokine Concentrations in Healthy Pregnancy and Preeclampsia

The maternal immune response is essential for successful pregnancy, promoting immune tolerance to the fetus while maintaining innate and adaptive immunity. Uncontrolled, increased proinflammatory responses are a contributing factor to the pathogenesis of preeclampsia. The Th1/Th2 cytokine shift theory, characterised by bias production of Th2 anti-inflammatory cytokine midgestation, was frequently used to reflect the maternal immune response in pregnancy. This theory is simplistic as it is based on limited information and does not consider the role of other T cell subsets, Th17 and Tregs. A range of maternal peripheral cytokines have been measured in pregnancy cohorts, albeit the changes in individual cytokine concentrations across gestation is not well summarised. Using available data, this review was aimed at summarising changes in individual maternal serum cytokine concentrations throughout healthy pregnancy and evaluating their association with preeclampsia. We report that TNF-α increases as pregnancy progresses, IL-8 decreases in the second trimester, and IL-4 concentrations remain consistent throughout gestation. Lower second trimester IL-10 concentrations may be an early predictor for developing preeclampsia. Proinflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-8, and IL-6) are significantly elevated in preeclampsia. More research is required to determine the usefulness of using cytokines, particularly IL-10, as early biomarkers of pregnancy health.

The Association of Circulatory Cytokines (IL-6 and IL-10) Level with Spontaneous Abortion-a Preliminary Observation

Successful pregnancy or its outcome depends upon various endogenous and exogenous determinants including immune status, and cytokines are one of the regulators which might play a vital role in the maintenance of pregnancy. The study was carried out to determine the role of cytokines, i.e., interleukin-6 (IL-6) and interleukin-10 (IL-10), in spontaneous abortion (SAb) cases with reference to control (women without SAb). One hundred twenty-six subjects (63 women with SAb cases and 63 control women without SAb and bearing at least one child) were enrolled. Out of the 63 SAb cases, 31 women from Outpatient Department (with history of SAb cases, i.e., one, two, or more) and 32 from the Gynecology ward (current SAb cases) were enrolled. The cytokines (IL-6 and IL-10) were measured by ELISA method using commercially available kit. The mean IL-6 level was higher among women with SAb cases, recent SAb and recurrent SAb cases versus controls, history of SAb and less than 2 SAb cases respectively, while an inverse pattern of variations was observed for IL-10 level. The Spearman's correlation revealed that the IL-6 was positively correlated while IL-10 was negatively correlated with number of incidences of SAbs. The data of women with recent SAb and childbirth were categorized into four IL quartiles and found that the highest % of control and lowest % of SAb subjects were in second quartile of IL-6 while highest % of control and lowest % of SAb subjects were in the fourth (high) quartile of IL-10 level group. A multiple regression model showed that with elevation in IL-6, there was an elevation in number of SAb cases and an inverse relationship was observed with regard to IL-10. The results indicate positive role of IL-10 and undesirable role of IL-6 on pregnancy outcomes. Further, quartiles' distribution suggests that high levels of IL-10 might be necessary for the effective pregnancy outcome, but more data are needed to substantiate the present findings.

Association of Promoter Region Polymorphisms of IL-6 and IL-18 Genes with Risk of Recurrent Pregnancy Loss: A Systematic Review and Meta-Analysis

Background: The present meta-analysis was performed to investigate the association of promoter region polymorphisms at IL-6 and IL-18 genes with recurrent pregnancy loss (RPL) risk. Methods: An electronic search of the PubMed, Embase, ISI Web of Knowledge and CNKI databases was performed to identify eligible studies up to May 30, 2019. Results: A total of 31 case-control studies were finally selected. Significant associations with the risk of RPL were detected for the IL-6 -174 G > C, -634 G > C and IL-18 -137 G > C polymorphisms in overall population. Further, subgroup analyses by ethnicity revealed that the IL-6 -174 G > C and -634 G > C polymorphisms were significantly associated with risk of RPL risk in Asians. Conclusions: Our results suggest that the IL-6 -174 G > C, -634 G > C and IL-18 -137 G > C polymorphisms may contribute to the susceptibility of RPL. The IL-18 -607 C > A polymorphism does not appear to influence the development of RPL.

Influence of single nucleotide polymorphisms (SNPs) in immunoregulatory genes in the morbidity of preterm newborns

Background: Prematurity is the main cause of perinatal and neonatal morbidity and mortality worldwide. Single nucleotide polymorphisms (SNPs) have been associated with the pathogenesis of morbidities in preterm neonates. We aimed to investigate the association between SNPs in regulatory genes of innate immune response IL1B, IL6, IL6R, IL10, TNFA, TNFRII, TLR2 and TLR4 and neonatal/infant morbidities in preterm newborns.Methods: Oral swabs were collected from 272 newborns (91 preterm and 181 at term) seen at Botucatu Medical School, Unesp, between 2013 and 2014 and SNPs were identified using Taqman^® Genotyping Assays. Medical records were examined to obtain data regarding neonatal/infant morbidity. Stepwise binomial logistic regression models were used to explain the morbidities.Results: Minor neonatal morbidity was influenced by the clinical parameters of maternal age and newborn weight at birth and by the presence of the allele IL6R2 C (rs2228145) while major neonatal morbidity was only influenced by gestational age. Minor infant morbidity was associated with the allele TLR2 T (rs4696480) and major infant morbidity was associated with gestational age and presence of IL6R2 C.Conclusion: The presence of SNPs that exacerbate the inflammatory response increases the susceptibility to neonatal and infant morbidity.

Interleukin-3 Polymorphism is Associated with Miscarriage of Fresh in Vitro Fertilization Cycles

The aim of this study was to examine the association between interleukin (IL) genes polymorphisms and in vitro fertilization (IVF) outcome. A prospective cohort analysis was performed at a Women’s Hospital IVF centre of 1015 female patients undergoing fresh non-donor IVF cycles. The effects of the following six single nucleotide polymorphisms (SNPs) in five IL genes on IVF outcomes were explored: IL-1α (rs1800587 C/T), IL-3 (rs40401 C/T), IL-6 (rs1800795 C/G), IL-15 (rs3806798 A/T), IL-18 (rs187238 C/G) and IL-18 (rs1946518 G/T). The main outcome measures included clinical pregnancy, embryo implantation, abortion and live birth rates. There were no statistically significant differences in clinical pregnancy, embryo implantation and live birth rates in the analysis of 1015 patients attempting their first cycle of IVF. Infertile women with IL-3 homozygous major genotype had a higher abortion rate than those with heterozygous and homozygous minor genotype (16.5% vs. 7.9%, P = 0.025). In conclusion, our results indicated that the IL-3 rs40401 polymorphism is associated with increased risk of abortion of IVF patients. Future studies with inclusion of other ethnic populations must be conducted to confirm the findings of this study.

Association between Genetic Polymorphisms in Interleukin Genes and Recurrent Pregnancy Loss - A Systematic Review and Meta-Analysis

Interleukins are a group of immunomodulatory proteins that mediate a variety of immune reactions in the human body. To investigate the association between interleukin gene polymorphisms and recurrent pregnancy loss (RPL), we reviewed 21 studies from MEDLINE, EMBASE, OVID SP and PubMed to evaluate RPL-related interleukin gene polymorphisms. Meta-analysis was performed on 12 of the polymorphisms, and a review included the others. Our integrated results indicated that IL-1β (-511C/T) (P = 0.02, 95% CI 0.77[0.62,0.96]), IL-6 (-634C/G) (P<0.001, 95% CI 2.91[2.01,4.22]), IL-10 (-1082G/A, -819T/C) (P = 0.01, 95% CI 0.80[0.67,0.96]; P<0.01, 95% CI 0.66[0.49,0.89]), and IL-18 (-137G/C, -105G/A) (P<0.01, 95% CI 1.69[1.24,2.31]; P = <0.01, 95% CI 1.41[1.17,1.70]) consistently associated with RPL after meta-analysis. IL-17A rs2275913 and IL-17F rs763780, IL-21 rs2055979 and rs13143866, IL-1β (-31C/T), IL-6 (-2954G/C), and IL-10 (-536A/G) were reported only once as having a significant association with RPL. The potential mechanism underlying miscarriage and these polymorphisms and future research directions are also discussed.

Compartmentalized localization of 11β-HSD 1 and 2 at the feto-maternal interface in the first trimester of human pregnancy

Glucocorticoids are engaged in a number of actions at the feto-maternal interface for the establishment of early pregnancy. However, excessive glucocorticoids can be deleterious to fetal development. Therefore, compartmentalized distribution of 11β-hydroxysteroid dehydrogenase 1 and 2 (11β-HSD1 and 2), which regenerates and inactivates cortisol respectively, would ensure an optimal cortisol concentration at the feto-maternal interface for the establishment of early gestation. However, the distribution pattern of 11β-HSD1 and 2 at the feto-maternal interface in early human pregnancy is not clearly defined. Here we showed that 11β-HSD1 distributed extensively on the maternal side including decidual stromal cells and epithelial cells but scarcely on the fetal side except for localization in the fetal blood vessels of the chorionic villi. In contrast, 11β-HSD2 was abundantly localized in syncytial layer of the chorionic villi and the decidual epithelium. In primary cultures, cortisol upregulated not only 11β-HSD1 expression in decidual stromal cells but also 11β-HSD2 expression in villous trophoblasts of early pregnancy. Further studies revealed that cortisol inhibited the expression of interleukin-1β and 6 in decidual stromal cells and villous trophoblasts, and stimulated expression of human chorionic gonadotropin in villous trophoblasts. Collectively, this study has revealed a compartmentalized distribution pattern of 11β-HSD 1 and 2 at the feto-maternal interface, both of which can be upregulated by glucocorticoids, suggesting that a coordinated interaction between 11β-HSD 1 and 2 may exist to ensure an optimal cortisol concentration at discrete locations at the feto-maternal interface for the establishment of early pregnancy.

Effect of interleukin 6 -174G>C gene polymorphism on opioid requirements after total hip replacement

Objective

In recent years, increasing attention has been paid to the contribution of genetic factors to variability in patient pain threshold and the efficacy of pain management. One of the genes implicated in pain pathology and treatment response is interleukin 6 (IL6). The aim of the present study was to evaluate the association between IL6 (rs1800795: –174G>C) and opioid requirements in patients after total hip replacement (THR).

Methods

A total of 196 patients eligible for the study (126 women, 70 men) were subjected to THR. The THR procedure was performed using spinal anaesthesia after implementing routine peri-operative monitoring. After the procedure each patient was individually observed, and the patient-specific chart of dynamic changes in pain perception was recorded, using the five-level Verbal Rating Scale (VRS). The multimodal analgesic treatment after THR was defined by the operating surgeons after considering indications and contraindications to the use of different groups of drugs (opioid and non-opioid analgesics). Postoperative pain was controlled by the patient-controlled analgesia method and VRS during the day-time, as well as night-time nurse-controlled analgesia. All medication adjustments were recorded in the individual patient files. In the case of moderate pain intensity (VRS-assessed), a patient was administered the non-opioid analgesic drug, and for high intensity pain the opioid. The analysis of pain relief therapy included information on the drugs applied, mode of dosing (single or multiple), daily dose, route of administration, and drug refusal due to the absence of pain recorded each study day, i.e. on the day of surgery and recovery in the postoperative room (day 0), and then daily from day 1 to day 6. Polymorphism rs1800795:G>C in the promoter region of the IL6 gene (–174G>C) was determined using the PCR–RFLP method.

Results

The patients carrying at least one IL6 –174G allele (GG homozygote and GC heterozygote) were administered opioids significantly more often on days 0 (p = 0.0029), 3 (p = 0.019) and 4 (p = 0.031) after surgery compared with CC homozygous patients. Those patients also required a significantly higher opioid dose on days 3 (p = 0.029) and 4 (p = 0.030). Multivariate analysis demonstrated that the presence of the –174G allele was an independent factor predisposing patients to the administration of opioids during the first 24 h [p = 0.001, odds ratio (OR) 7.1, 95 % confidence interval (CI) 2.17–22.7], on day 3 (p = 0.01, OR 2.79, 95 % CI 1.25–6.26) and day 4 (p = 0.01, OR = 2.61, 95 % CI 1.17–5.79).

Conclusion

The presence of the G allele IL6 gene (–174G>C) polymorphism was found to be an independent factor predisposing to a higher dose and more frequent administration of opioids in the first days after total hip replacement.

First trimester interleukin-6 levels help to predict adverse pregnancy outcomes in both thyroid autoantibody positive and negative patients

AIM

The aim of the present study is to compare pregnancy outcomes among patients with and without thyroid antibodies and/or subclinical hypothyroidism and investigate whether there is an association between first trimester maternal plasma interleukin-6 (IL-6) levels and adverse pregnancy outcomes.

METHODS

A case-control study was carried out including 83 pregnant women (40 thyroid antibody positive and 43 healthy controls). The predictive value of first trimester maternal plasma IL-6 levels on adverse pregnancy outcomes were investigated. The optimal cut-off points of IL-6 for determining maternal and fetal outcomes were evaluated by receiver operating characteristic analyses.

RESULTS

Compared with the control, median IL-6 levels were significantly higher in thyroid antibody positive pregnancies (median 1.58 vs 1.63 pg/mL; P = 0.047). IL-6 levels were found to be significantly higher in women who had suffered a miscarriage (P = 0.002), preterm delivery (P < 0.001), intrauterine growth restriction (P = 0.047), preterm premature rupture of membranes (P = 0.043) and overall prenatal complications (P < 0.001). A statistically significant negative correlation between gestational week at birth and IL-6 levels was also determined among all participants involved in the study (r = -0.385, P < 0.001).

CONCLUSION

IL-6 levels are significantly increased in thyroid antibody positive patients and predictive for future adverse outcomes, irrespective of thyroid autoimmunity. Increased first trimester IL-6 levels independently predict adverse pregnancy outcomes, regardless of subclinical hypothyroidism.

Role of IL-6 -174(G/C) promoter polymorphism in the etiology of early-onset preeclampsia

OBJECTIVE

To investigate the relationship between IL-6 -174G/C promoter polymorphism and preeclampsia.

METHODS

A total of 140 preeclamptic women and 135 women with normal pregnancy were considered for the present study. A standard amplification refractory mutation system PCR was carried out for genotyping of IL-6 G-174C promoter polymorphism. Genotypic distribution was compared with values predicted by Hardy-Weinberg equilibrium using χ (2) test. Odds ratios and their respective 95 % confidence intervals were used to measure the strength of association.

RESULTS

The frequencies observed, CC, GC and GG, were 53.5, 26.6 and 20 % in patients and 26.6, 23.7 and 49.6 % in the controls. There is a significant difference in the distribution of genotypes and alleles of IL-6 G-174 C between the two groups.

CONCLUSION

The present study suggests that the IL-6 -174 promoter polymorphism is a major genetic regulator in the etiology of early-onset preeclampsia.