Effect of ovaric hyper-stimulation on blood lymphocyte subpopulations, cytokines, leptin and nitrite among patients with unexplained infertility

Serum leptin level in Sudanese women with unexplained infertility and its relationship with some reproductive hormones

BACKGROUND

The excessive concentration of leptin has negative effects on all aspects of female reproduction. Despite this established relationship, the exact role of leptin in women’s fertility is not clear enough and needs more clarification.

AIM

To evaluate the serum leptin levels in Sudanese women and to ascertain the relationship between serum leptin levels and unexplained infertility (UI).

METHODS

A matched (age and body mass index) case-control study was conducted from March 2021 to February 2022. The study samples were 210 women with UI and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum state Sudan. The serum concentration of leptin and other serum biomarkers were determined using enzyme-linked immunosorbent assays.

RESULTS

The results showed that there was a highly statistically significant difference between the two groups (P < 0.001) for all examined eight biomarkers. Whereby, leptin, luteinizing hormone (LH)/follicular stimulating hormone (FSH) ratio, prolactin hormone (PRL) and testosterone (T) were significantly higher in the UI group compared with the control group. In contrast, FSH and estradiol (E2)/T ratio were significantly lower in the UI group than in the control group and the effect size test for the difference between the two groups was very large (effect size > 0.80), for leptin level, LH/FSH ratio, PRL level, and E2/T ratio, and large (effect size 0.50- ≤ 0.80) for FSH and T.

CONCLUSION

This study reveals that leptin could be a potential biomarker for UI in Sudanese women and it may be useful for identifying women with a high risk of infertility.

Leptin levels in women with unexplained infertility: A systematic review and meta-analysis

BACKGROUND

Unexplained infertility (UI) is usually used for any heterosexual couple who failed to have a successful clinical pregnancy without identifying clear causes after they undergo all standard fertility tests. Evidence shows that leptin is one of the most accurate biomarkers for UI. Nevertheless, conflicting results regarding leptin levels in women with UI have been reported.

AIM

To find the serum leptin levels in women with UI.

METHODS

All studies written in English and conducted before April 30, 2021 from PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Google Scholar, OpenGrey, OATD, and the infertility conference abstract were included. Studies were found eligible if they provided the mean and standard deviation of leptin for the case group and control group. The quality assessment of individual studies was evaluated using the Joanna Briggs Institute Quality Assessment Tool. Data synthesis and statistical analysis were done using STATA software version 16.

RESULTS

A total of 378 studies were reviewed, and just six studies that fulfilled the eligibility criteria were included in this meta-analysis. The pooled result showed that leptin levels were significantly higher in women with UI compared to fertile women, with a standardized mean difference of 0.97 (95% confidence interval: -0.49-2.43). However, heterogeneity across studies was highly significant (P < 0.00001; I² = 98.8%).

CONCLUSION

The results of this study suggest that leptin levels are elevated in women with UI compared with fertile women; hence, leptin could be a potential biomarker for UI in women, and it may be useful for identifying women with a high risk of infertility.

The Role of Inflammatory Hematological Markers in Predicting IVF Success

Objective:

To investigate the predictive role of inflammatory hematological markers on treatment success in in vitro fertilization (IVF) patients.

Methods:

In this study, we analyzed the data from the patients who admitted to our IVF center, and we recorded demographic characteristics, medical histories, laboratory biomarkers, cycle characteristics, and IVF outcomes from the patients’ files. We assessed the value of white blood cell (WBC) counts, neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR), platelet/lymphocyte (PLR), mean platelet volume (MPV) and platelet distribution width (PDW) of the patients from their complete blood count. We compared these values in terms of predicting positive HCG test after embryo transfer (ET).

Results:

There were 132 patients, of which 63 (47.7%) were treated for male factor, 43 (32.6%) for unexplained infertility, 19 (14.4%) for diminished ovarian reserve, 5 (3.8%) for endometriosis and 2 (1.5%) for hypogonadotropic hypogonadism. After ovarian stimulation and oocyte retrieval, 115 patients underwent embryo transfer, and 28 patients had a positive HCG test (24.3%). The positive HCG group had a statistically lower PLR when compared to the HCG (-) group (p=0.02). In the ROC analysis, PLR was significant in predicting positive HCG (p=0.028). However, when we added other factors to the model, only age and MII oocyte count were successful in predicting pregnancy outcomes in a logistic regression analysis.

Conclusion:

According our results, inflammatory hematological markers were not effective in predicting IVF success.

Ovarian stimulation does not influence the uterine immune environment in healthy infertile women

RESEARCH QUESTION

There is some controversy regarding the impact of ovarian stimulation on immune cells in women undergoing IVF. The study's aim was to determine whether ovarian stimulation affected immune uterine cells in healthy women undergoing IVF.

DESIGN

This prospective cohort study included 28 patients undergoing IVF and 47 healthy oocyte donors. Endometrial biopsies were taken in a natural cycle and after ovarian stimulation. All participants had a normal karyotype, pelvic ultrasound and cervical cytology results and thyroid-stimulating hormone concentration, as well as normal glucose and insulin concentrations and inherited and acquired thrombophilia test results. Screening tests including human papillomavirus were normal. Immune cells were analysed using three techniques: fluorescence-activated cell sorting, immunohistochemistry and gene expression. A human leukocyte antigen (HLA)-C tetramer was used as an 'artificial embryo'. The expression of genes including those for tumour necrosis factor (TNF)-α and interleukin-10 (IL-10) was analysed.

RESULTS

A comparison was made of the percentage and gene expression of CD56^brightCD16^- uterine natural killer (uNK), CD56^dimCD16⁺ natural killer cells, CD56^-CD16⁺ natural killer cells and TregCD25⁺CD4⁺FoxP3⁺ cells, uNK binding to the HLA-C tetramer, and TNF-α and IL-10 expression. No between- or within-group differences were observed in natural versus ovarian stimulation cycles.

CONCLUSIONS

Ovarian stimulation does not affect the uterine immune cell population or HLA-C binding in healthy women undergoing ovarian stimulation. Further studies are underway to find out if different responses might be seen in women with previous autoimmune disorders.

The Effects of Chromium Supplementation on Gene Expression of Insulin, Lipid, and Inflammatory Markers in Infertile Women With Polycystic Ovary Syndrome Candidate for in vitro Fertilization: A Randomized, Double-Blinded, Placebo-Controlled Trial

Purpose: This study was performed to determine the effects of chromium supplementation on the gene expression of insulin, lipid, and inflammatory markers in infertile women with polycystic ovary syndrome (PCOS) who were candidate for in vitro fertilization (IVF). Methods: Forty women, aged 18-40 years, who had been selected for IVF were recruited in this randomized double-blinded, placebo-controlled trial. They (n = 20/group) were randomly assigned into intervention groups to take either 200 μg/day of chromium or placebo for 8 weeks. Inflammatory markers were measured at baseline and end of the trial. Genes related to insulin, lipid, and inflammation were expressed in peripheral blood mononuclear cells (PBMCs), using RT-PCR method. Results: Chromium supplementation led to a significant reduction in serum high sensitivity C-reactive protein (hs-CRP) (-1.4 ± 1.5 vs. + 0.2 ± 2.2 mg/L, p = 0.01) compared with the placebo. RT-PCR findings indicated that chromium supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (p = 0.01), glucose transporter 1 (GLUT-1) (p = 0.001) and low-density lipoprotein receptor (LDLR) (p = 0.01), as well as downregulated gene expression of interleukin-1 (IL-1) (p = 0.004) in PBMCs of patients with PCOS compared with the placebo. Chromium supplementation had no significant effect on gene expression of IL-8, tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF). Conclusion: Overall, our findings demonstrated that infertile women with PCOS, who were candidate for IVF benefited from chromium supplementation for 8 weeks in terms of lowering hs-CRP and improving gene expression of PPAR-γ, GLUT-1, LDLR, and IL-1, though chromium had no effect on the gene expression of IL-8, TNF-α, TGF-β, and VEGF. Clinical Trial Registration Number: http://www.irct.ir:IRCT20170513033941N32.

Natural killer cells in female infertility and recurrent miscarriage: a systematic review and meta-analysis

INTRODUCTION Embryo implantation is a complex process involving maternal hormonal changes, immune responses and maturational events in the embryo. A pregnancy could fail when these events are not synchronized. It is speculated that in women, an elevation of natural killer (NK) cells may have an effect on reproductive performance, and NK cell levels in blood are currently being used as a diagnostic test to guide the initiation of therapies in patients with infertility. METHODS We conducted a systematic review to evaluate the (i) levels of NK cells in blood and endometrium in infertile versus fertile women, (ii) association between NK cells and IVF outcome, (iii) levels of NK cells in blood and endometrium in women with recurrent miscarriage (RM) versus controls. The following electronic databases were searched: Medline, EMBASE, Cochrane Library, Web of Science and National Research Register. RESULTS A total of 22 studies were included. Meta-analysis of studies that evaluated peripheral and uterine NK (uNK) cell percentages in infertile versus fertile women showed no significant difference between the two groups [standardized mean difference (SMD) -0.33; 95% confidence intervals (CI) -1.06, 0.4; P = 0.37; SMD -1.82; 95% CI -4.80, 1.17; P = 0.23 respectively]. Pooling of studies that reported peripheral NK cells as numbers showed significantly higher NK cell numbers in infertile women compared with fertile controls (SMD 3.16; 95% CI 1.07, 5.24; P = 0.003). Meta-analysis of studies that evaluated the role of NK cells in IVF outcome showed no significant difference in live birth rates in women with elevated NK cells or NK cell activity compared with women without elevated peripheral NK cells or NK cell activity (NK activity assessed using a cytotoxicity assay) (relative risk 0.57; 95% CI 0.06, 5.22; P = 0.62). Meta-analysis of studies that evaluated peripheral NK cell percentages in women with RM versus controls showed significantly higher NK cell percentages in women with RM (SMD 1.36; 95% CI 0.04, 2.69; P = 0.04). Meta-analysis of studies that evaluated peripheral NK cell numbers showed significantly higher NK cell numbers in women with RM compared with controls (SMD 0.81; 95% CI 0.47, 1.16; P < 0.00001). Meta-analysis of studies that evaluated uNK cells showed no significant difference in women with RM compared with controls (SMD 0.40; 95% CI -1.24, 2.04; P = 0.63). CONCLUSIONS Further research is needed before NK cell assessment can be recommended as a diagnostic tool in the context of female infertility or RM. There is no clear explanation as to why the results differ when data for NK cells are expressed as numbers or a percentage. On the basis of current evidence, NK cell analysis and immune therapy should be offered only in the context of clinical research.

Cytokines in recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss (RPL) is defined as the occurrence of three or more consecutive miscarriages prior to 20 weeks gestation. Exaggerated maternal immune response to fetal antigens has been proposed to be one of the mechanisms underlying recurrent pregnancy loss.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

In normal pregnancy, tolerance of the genetically incompatible fetus by the maternal immune system depends on the interactions of an array of cytokines secreted by maternal and fetal cells at the site of implantation. Earlier research indicated that altered immunity in RPL is dominated by the Th1/Th2 hypothesis, which proposed that the fetus escapes maternal-derived T-cell responses through skewing the Th0 differentiation toward Th2 pathway which dampens pro-inflammatory Th1-type immunity. Recent studies indicate the role of proinflammatory Th17 cells and immunoregulatory Treg cells in RPL in addition to Th1/Th2 interactions.

CONCLUSION

Cytokines form a complex regulatory network which maintains homeostasis between the fetal unit and the maternal immune system. If this delicate balance is adversely affected, immunoregulatory mechanisms may be insufficient to restore homeostasis and this may lead to pregnancy failure.

The essential roles of TGFB1 in reproduction

Transforming growth factor beta 1 (TGFB1) is implicated as a key regulator of the development and cyclic remodelling characteristic of reproductive tissues. The physiological significance of TGFB1 in reproductive biology and fertility has been extensively examined in Tgfb1 null mutant mice. Genetic deficiency in TGFB1 causes perturbed functioning of the hypothalamic-pituitary-gonadal axis, inhibiting luteinising hormone (LH) synthesis and leading to downstream effects on testosterone production in males and estrous cycle abnormalities in females. Oocyte developmental incompetence, accompanied by early embryo arrest as well as altered pubertal mammary gland morphogenesis are observed. In addition to LH and testosterone deficiency, male Tgfb1 null mice demonstrate complete inability to mate with females, associated with failure to initiate and/or sustain successful penile intromission or ejaculation. These studies demonstrate the profound significance of TGFB1 in male and female reproductive physiology, and provide a foundation for exploring the significance of this cytokine in human infertility and sexual dysfunction.

Alterations in biomarkers of cardiovascular disease (CVD) in active acromegaly

OBJECTIVES

In acromegalic patients, cardiovascular and metabolic comorbidities contribute to enhance mortality. Available data on the lipoprotein profile of these patients are controversial. Our aim was to characterize the lipoprotein profile and emergent biomarkers of cardiovascular disease in active acromegalic patients in comparison with sex- and age-matched healthy controls.

PATIENTS

Eighteen patients with active acromegaly and 18 controls were studied.

MEASUREMENTS

Glucose levels, hormonal status, lipoprotein profile and C reactive protein (CRP) were evaluated by standardized methods. Cholesteryl ester transfer protein (CETP) and lipoprotein-associated phospholipase A(2 )(Lp-PLA(2)) were measured by radiometric techniques, endothelin-1 and vascular cell adhesion molecule (VCAM)-1 by enzyme-linked immunosorbent assay, and leucocytes CD18, CD49d and CD54 by flow cytometry.

RESULTS

After adjusting for body mass index (BMI), acromegalic patients presented a more atherogenic lipoprotein profile, consisting of higher levels of triglycerides and apolipoprotein B and alterations in the ratios which estimate insulin resistance and atherogenic risk. CETP activity was significantly increased in acromegalic patients as compared to controls (168 +/- 17 vs. 141 +/- 30% per ml h, respectively; P < 0.05). Endothelin-1 levels evidenced an increase in the patients' group (0.9 +/- 0.2 vs. 0.7 +/- 0.2 ng/l, respectively; P < 0.01) and showed positive and significant correlations with GH, IGF-1 and IGFBP-3 (r = 0.45, 0.42 and 0.44, respectively; P < 0.01 for all of them; with BMI as a fixed variable). Lymphocytes from acromegalic patients showed increased CD49d content (282 +/- 59 vs. 246 +/- 48 arbitrary units, respectively; P < 0.05).

CONCLUSIONS

Taken together, the alterations described seem to contribute to constituting a state of higher propensity for the development of atherosclerotic cardiovascular disease, which adds to the presence of specific cardiomyopathy.

Alterations in cell adhesion molecules and other biomarkers of cardiovascular disease in patients with metabolic syndrome

Metabolic syndrome is considered a hyperinsulinemic and inflammatory state closely associated to endothelial dysfunction causing an increased incidence of ischemic cardiovascular events and high mortality. The main objective of the present study was to determine whether leukocitary and soluble cell adhesion molecules were altered in patients with metabolic syndrome in comparison with control subjects. Cell adhesion molecules, mainly of leukocitary location, have been not previously evaluated in specifically designed cross-sectional studies involving male patients with metabolic syndrome. Moreover, other circulating markers of different candidate atherogenic risk parameters were also studied and the potential existence of a progressive relation between the number of metabolic syndrome components and the above mentioned biomarkers was analyzed. Thirty one male patients with metabolic syndrome (ATPIII definition) and 56 male control subjects were studied. We evaluated different markers of insulin resistance, inflammation and atherosclerosis, as well as protective factors. Patients with metabolic syndrome showed (a) hypoadiponectinemia (4551 +/- 2302 ng/ml vs. 5865 +/- 2548 ng/ml, respectively; p<0.05), (b) an atherogenic lipid and lipoprotein profile, (c) altered HDL chemical composition accompanied by higher cholesteryl ester-triglyceride interchange carried out by CETP, (d) diminished Lp-PLA(2) activity (6.5 +/- 1.9 vs. 7.3 +/- 2.2, p<0.05, respectively), antioxidant enzyme related with LDL oxidation, which was positively associated with QUICKI and negatively with VCAM-1 and lymphocyte CD18, and (e) high soluble (VCAM-1: 17 +/-5 vs. 13 +/- 4 ng/ml, respectively; p<0.0005) and leukocyte adhesion molecule expression (monocyte CD54: 52 +/- 15 vs. 45 +/-12 arbitrary units, respectively; p<0.0005; and lymphocyte CD49d: 312 +/- 56 vs. 284 +/- 64 arbitrary units, respectively; p < 0.05). The increment in leukocyte and soluble cell adhesion molecules, crucial for leukocyte interaction with the endothelium and migration into the artery wall, in combination with the other disorders described above reinforce the presence of a clinical status with high propensity to type 2 diabetes and atherosclerotic cardiovascular disease.

Endothelial and leukocyte adhesion molecules in primary hypertriglyceridemia

Hypertriglyceridemia is known to be associated to functional impairment of the endothelium and, consequently, to higher risk of atherosclerosis. Nevertheless, some crucial steps in the development of the atherosclerotic plaque are still unknown in primary hypertriglyceridemia. The aim of the present study was to explore the expression of soluble and leukocyte-associated cell adhesion molecules in a group of patients with primary hypertriglyceridemia, both including (n=50) and excluding (n=24) subjects with metabolic syndrome, in comparison with control normotriglyceridemic individuals (n=30). Lipid profile, CETP activity, HDL and VLDL chemical composition were evaluated. Soluble (VCAM-1, ICAM-1 and E-selectin) and leukocyte cell adhesion molecules (CD18, CD49d and CD54) were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Patients with primary hypertriglyceridemia as compared with control subjects showed significantly higher VCAM-1 (15.6+/-4.5 ng/ml versus 13.9+/-3.8 ng/ml, respectively; p<0.05) and ICAM-1 (16.9+/-3.1 ng/ml versus 15.2+/-3.2 ng/ml, respectively; p<0.05). Regarding leukocyte cell adhesion molecules, significant increases were also detected in monocyte CD18 (398+/-180 versus 332+/-136 arbitrary units, respectively; p<0.05) and CD54 (49+/-14 versus 42+/-12 arbitrary units, respectively; p<0.05), and lymphocyte CD18 (122+/-53 versus 101+/-33 arbitrary units, respectively; p<0.05). ICAM-1 plasma levels, as well as monocyte CD18 and CD54, and lymphocyte CD18 persisted elevated even if patients with metabolic syndrome were discarded among those with hypertriglyceridemia. The increase in circulating and leukocyte cell adhesion molecules in primary hypertriglyceridemic patients would highlight the inflammatory process which is a key event in atherogenesis.

T-Helper 2 and 3 type immunity to trophoblast in successful in vitro fertilization-embryo transfer

OBJECTIVE

To determine whether peripheral blood mononuclear cell (PBMC) secretion of T-helper (Th)-1 type cytokines and Th-2 and Th-3 type cytokines in women undergoing in vitro fertilization-embryo transfer (IVF-ET) is associated with therapeutic failure and success, respectively.

DESIGN

Cohort study.

SETTING

Academic medical center.

PATIENT(S)

One hundred one women undergoing IVF-ET and 19 fertile controls.

INTERVENTION(S)

Peripheral blood was obtained from women undergoing IVF-ET before oocyte retrieval and from 19 nonpregnant fertile controls. The PBMCs were cultured in the presence or absence of a protein extract from either a trophoblast cell line or sperm membrane.

MAIN OUTCOME MEASURE(S)

Supernatants from PBMC cultures were tested by enzyme-linked immunoabsorbent assay (ELISA) for the Th-1 type cytokines tumor necrosis factor-alpha (TNF)-alpha) and interferon-gamma (IFN)-gamma), the Th-2 type cytokines interleukin (IL)-6 and IL-10, and the Th-3 type cytokine transforming growth factor (TGF)-beta1.

RESULT(S)

Levels of IL-6 and IL-10 were significantly higher in controls than in infertile women with endometriosis, and levels of IL-10 were higher in controls than in women with unexplained infertility. No differences were found in unstimulated levels of TNF-alpha, IFN-gamma, or TGF-beta1 between infertile patients and controls. In trophoblast-stimulated PBMC cultures, levels of TGF-beta1 were significantly lower in subjects who experienced failed compared with ongoing pregnancies.

CONCLUSION(S)

Baseline PBMC secretion of IL-6 and IL-10 is higher in fertile controls than in women with endometriosis, and IL-10 secretion is also higher than in women with unexplained infertility. Trophoblast-stimulated PBMC secretion of TGF-beta1 is positively associated with the establishment of successful pregnancy in women undergoing IVF-ET. Our study provides novel evidence to support a faciliatory role of Th-2 and Th-3 type responses to trophoblast in early pregnancy.

Preconception Peripheral Natural Killer Cell Activity as a Predictor of Pregnancy Outcome in Patients with Unexplained Infertility

PROBLEM

Preconception high peripheral natural killer (NK) cell activity in women with recurrent spontaneous abortion can predict subsequent miscarriages. We have examined prospectively, for the first time, the pregnancy rate in patients with unexplained infertility by measuring the peripheral NK activity.

METHOD OF STUDY

We tested the peripheral NK activity of 94 infertile women who despite treatment were unable to conceive for 6 or more months (mean; 2.4 years). Peripheral NK activity was measured by a chromium-51 release cytotoxicity assay. Women were followed for 2 years and assessed.

RESULTS

In 77 patients who were followed for 2 years, 28 had conceived but 49 did not. The peripheral NK activity of the group that became pregnant (mean +/- S.D.; 34.5 +/- 13.8%) was significantly lower than that of non-conception group (42.3 +/- 13.3%, P = 0.017).

CONCLUSIONS

Our finding suggests that elevated peripheral NK activity in patients with unexplained infertility is a risk factor for attaining pregnancy success.

Natural killer cells in pregnancy and recurrent pregnancy loss: endocrine and immunologic perspectives

The endocrine system and the immune system interact closely during implantation and maintenance of pregnancy. One of the most striking examples of this communication is at the level of the decidua (endometrium of pregnancy). Here, under the influence of sex steroids, there is a dramatic increase of a unique population of lymphocytes, the uterine natural killer (uNK) cells, in early pregnancy. These cells derive predominantly from a subset of peripheral blood NK cells, which under hormonal influence gets recruited to the uterus. In mice, uNK cells play an important role in the development of placental vasculature. The role of these cells in human pregnancy is still not definitively established; however, they are believed to promote placental and trophoblast growth and provide immunomodulation at the maternal-fetal interface. In contrast to their presumptive role in the maintenance of a healthy pregnancy, uNK cells and peripheral NK cells are dysregulated in unexplained recurrent pregnancy loss. Herein, we review NK cell populations, their changes in number and function in altered endocrine environments during the menstrual cycle and pregnancy, the current data on their potential role in unexplained recurrent pregnancy loss, and mechanisms for potential therapies targeted to NK cell function for this enigmatic disorder.