The SPRi determination of cathepsin L and S in plasma and peritoneal fluid of women with endometriosis.

PURPOSE: Endometriosis is a common disease with a complex pathomechanism and atypical symptoms, often leading to delayed diagnosis. Currently, the sole method for confirming the presence of the disease is through laparoscopy and histopathological examination of collected tissue. However, this invasive procedure carries potential risk and complications, necessitating the exploration of non-surgical diagnostic methods for endometriosis. This study aims to analyze peritoneal fluid and plasma samples for the expression of cathepsin L and cathepsin S to identify potential biomarkers for non-invasive diagnostic approaches to endometriosis. MATERIAL AND METHODS: In this cross-sectional study, plasma and peritoneal fluid samples were obtained during laparoscopy from 63 patients diagnosed with chronic pelvic pain or infertility. The study group consisted of women with confirmed endometriosis. The concentrations of cathepsins L and S were determined using an SPRi biosensor. RESULTS: The study did not reveal significant differences in the concentrations of cathepsin L and cathepsin S between the control group and the study group, both in peritoneal fluid and plasma. CONCLUSIONS: Based on the results of this study, it appears that cathepsins L and S are not suitable candidates as biomarkers for endometriosis.

Is the leptin/BMI ratio a reliable biomarker for endometriosis?

Background: The aim of this study was to analyze the concentration of leptin in peritoneal fluid and plasma and to assess their role as potential biomarkers in the diagnosis of endometriosis. Materials & methods: Leptin adjusted for BMI (leptin/BMI ratio) was measured using surface plasmon resonance imaging (SPRI) biosensors. Patients with suspected endometriosis were included in the study. Plasma was collected from 70 cases, and peritoneal fluid from 67 cases. Based on the presence of endometriosis lesions detected during laparoscopy, patients were divided into a study group and a control group (patients without endometriosis). Results: Leptin/BMI ratio in plasma did not differ between women with endometriosis and the control group (0.7159 ± 0.259 vs 0.6992 ± 0.273, p= 0,7988). No significant differences were observed in peritoneal leptin/BMI ratio levels in patients with and without endometriosis (0.6206 ± 0.258 vs 0.6215 ± 0.264, p= 0,9896). Plasma and peritoneal leptin/BMI ratios were significantly lower in women with endometriosis - related primary infertility compared to women with endometriosis without primary infertility (0.640 ± 0.502 vs 0.878 ± 0.623, p < 0.05). The difference was observed in case of primary infertility, but not in terms of the secondary one. No significant differences were noted between leptin/BMI ratio in the proliferative phase and the secretory phase (0.716 ± 0.252 vs 0.697 ± 0.288, p= 0,7785). Conclusion: The results of present study do not support the relevance of leptin concentration determination as a biomarker of the endometriosis. Due to the limited number of samples in the tested group, further studies are needed to confirm its role.

Plasma and Peritoneal Fluid Annexin A2 Levels in Patients with Endometriosis.

Introduction: Endometriosis is an inflammatory-related reproductive age disease characterized by the presence of endometrial cells outside the uterine cavity. Current laboratory practice does not provide specific markers for detecting and assessing the advancement of endometriosis in either plasma or peritoneal fluid. The severity of disease is assessed in stages from I to IV based on the results of laparoscopic inspection. The protein annexin A2 (ANXA2) has been reported to be associated with inflammatory processes. Aim of the Study: The study aimed to investigate and compare ANXA2 protein concentration using the ELISA method in plasma and peritoneal fluid in a group of women with endometriosis compared to controls. Materials and Methods: Biological material was collected during a multicenter, cross-sectional study, which was conducted at eight departments during elective laparoscopy from 53 women with and 40 women without endometriosis. Patients were divided by endometriosis stage and infertility status, and then compared with subgroups. Analysis included the Chi-square test for categorical variables, Mann-Whitney U-test and two-sided Wilcoxon rank-sum test for continuous variables. Results: Women with endometriosis had significantly elevated plasma ANXA2 levels compared to women without endometriosis (mean concentrations 28.69 vs 19.61 ng/L, p=0.01). Differences in peritoneal fluid ANXA2 levels were statistically insignificant (mean concentrations of 23.7 vs 22.97 ng/L, p=0.06). Plasma concentrations in patients with stage III and IV endometriosis were significantly higher compared to controls (mean concentrations of 24.19 vs 19.71 ng/L, p=0.03). No such differences were observed in plasma when comparing stages I-II vs III-IV, and stages I-II vs controls (mean concentrations of 33.82 vs 24.19 ng/L, p=0.72 and 33.82 vs 19.71 ng/L, p=0.12, respectively). Comparison of samples from patients with or without infertility, primary or secondary infertility, endometriosis with or without infertility, and non-endometriosis with or without infertility showed no significant differences in the plasma nor in the peritoneal fluid concentrations. Conclusion: ANXA2 is possibly involved in the pathogenesis of endometriosis, especially in advanced stages. Due to the limited group of tested samples, further studies are needed to confirm its role.

Evaluation of Proteasome and Immunoproteasome Levels in Plasma and Peritoneal Fluid in Patients with Endometriosis.

Endometriosis is a chronic disease in which the endometrium cells are located outside the uterine cavity. The aim of this study was to evaluate circulating 20S proteasome and 20S immunoproteasome levels in plasma and peritoneal fluid in women with and without endometriosis in order to assess their usefulness as biomarkers of disease. Concentrations were measured using surface plasmon resonance imaging biosensors. Patients with suspected endometriosis were included in the study-plasma was collected in 112 cases and peritoneal fluid in 75. Based on the presence of endometriosis lesions detected during laparoscopy, patients were divided into a study group (confirmed endometriosis) and a control group (patients without endometriosis). Proteasome and immunoproteasome levels in both the plasma (p = 0.174; p = 0.696, respectively) and the peritoneal fluid (p = 0.909; p = 0.284, respectively) did not differ between those groups. There was a statistically significant difference in the plasma proteasome levels between patients in the control group and those with mild (Stage I and II) endometriosis (p = 0.047) and in the plasma immunoproteasome levels in patients with ovarian cysts compared to those without (p = 0.017). The results of our study do not support the relevance of proteasome and immunoproteasome determination as biomarkers of the disease but suggest a potentially active role in the pathogenesis of endometriosis.

Investigation of the Changes in Concentrations of Vitamin D-Binding Protein and Lactoferin in Plasma and Peritoneal Fluid of Patients with Endometriosis.

An evaluation of the association between the concentrations of vitamin D-binding protein and lactoferrin in the plasma and peritoneal fluid may facilitate the elucidation of molecular mechanisms in endometriosis. Vitamin D-binding protein and lactoferrin concentrations were measured by ELISA in plasma and peritoneal fluid samples from 95 women with suspected endometriosis as classified by laparoscopy into groups with (n = 59) and without endometriosis (n = 36). There were no differences (p > 0.05) in the plasma and peritoneal fluid concentrations of vitamin D-binding protein and lactoferrin between women with and without endometriosis. In women with endometriosis, there was a significant correlation between plasma and peritoneal fluid vitamin D-binding protein concentrations (r = 0.821; p = 0.000), but there was no correlation between lactoferrin concentrations in those compartments (r = 0.049; p > 0.05). Furthermore, in endometriosis, lactoferrin was found to correlate poorly with vitamin D-binding protein (r= -0.236; p > 0.05) in plasma, while in the peritoneal fluid, the correlation between those proteins was significant (r = 0.399; p = 0.002). The characteristic properties of vitamin D-binding protein and lactoferrin and the associations between their plasma and peritoneal fluid concentrations found in women with endometriosis may provide a novel panel of markers to identify high-risk patients in need of further diagnostic measures.

Autoantibody screening of plasma and peritoneal fluid of patients with endometriosis.

STUDY QUESTION: Are there specific autoantibody profiles in patients with endometriosis that are different from those in controls? SUMMARY ANSWER: This study did not reveal a significantly higher prevalence of autoantibodies in the studied groups of patients. WHAT IS KNOWN ALREADY: Various inflammatory factors are postulated to be involved in the pathomechanisms of endometriosis, and a potential link exists with autoimmune diseases, which may also play an important role. As the diagnosis of endometriosis remains invasive, it can only be confirmed using laparoscopy with histopathological examination of tissues. Numerous studies have focused on identifying useful biomarkers to confirm the disease, but without unequivocal effects. Autoantibodies are promising molecules that serve as potential prognostic factors. STUDY DESIGN, SIZE, DURATION: A multicentre, cross-sectional study was conducted over 18 months (between 2018 and 2019), at eight Departments of Obstetrics and Gynaecology in several cities across Poland on 137 patients undergoing laparoscopic examination for the diagnosis of endometriosis. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: During laparoscopy, we obtained plasma samples from 137 patients and peritoneal fluid (PF) samples from 98 patients. Patients with autoimmune diseases were excluded from the study. Autoantibody profiling was performed using HuProt v3.1 human proteome microarrays. MAIN RESULTS AND THE ROLE OF CHANCE: We observed no significant differences in the expression of autoantibodies in the plasma or PF between the endometriosis and control groups. The study revealed that in the PF of women with Stage II endometriosis, compared with other stages, there were significantly higher reactivity signals for ANAPC15 and GABPB1 (adj. P < 0.016 and adj. P < 0.026, respectively; logFC > 1 in both cases). Comparison of the luteal and follicular phases in endometriosis patients revealed that levels of NEIL1 (adj. P < 0.029), MAGEB4 (adj. P < 0.029), and TNIP2 (adj. P < 0.042) autoantibody signals were significantly higher in the luteal phase than in the follicular phase in PF samples of patients with endometriosis. No differences were observed between the two phases of the cycle in plasma or between women with endometriosis and controls. Clustering of PF and plasma samples did not reveal unique autoantibody profiles for endometriosis; however, comparison of PF and plasma in the same patient showed a high degree of concordance. LIMITATIONS, REASONS FOR CAUTION: Although this study was performed using the highest-throughput protein array available, it does not cover the entire human proteome and cannot be used to study potentially promising post-translational modifications. Autoantibody levels depend on numerous factors, such as infections; therefore the autoantibody tests should be repeated for more objective results. WIDER IMPLICATIONS OF THE FINDINGS: Although endometriosis has been linked to different autoimmune diseases, it is unlikely that autoimmune responses mediated by specific autoantibodies play a pivotal role in the pathogenesis of this inflammatory disease. Our study shows that in searching for biomarkers of endometriosis, it may be more efficient to use higher-throughput proteomic microarrays, which may allow the detection of potentially new biomarkers. Only research on such a scale, and possibly with different technologies, can help discover biomarkers that will change the method of endometriosis diagnosis. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by a grant from the Polish Ministry of Health (grant no. 6/6/4/1/NPZ/2017/1210/1352). It was also funded by the Estonian Research Council (grant PRG1076) and the Horizon 2020 Innovation Grant (ERIN; grant no. EU952516), Enterprise Estonia (grant no. EU48695), and MSCA-RISE-2020 project TRENDO (grant no. 101008193). The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

The Influence of Lactoferrin in Plasma and Peritoneal Fluid on Iron Metabolism in Women with Endometriosis.

The aim of this study was to investigate the relationship between lactoferrin and iron and its binding proteins in women with endometriosis by simultaneously measuring these parameters in plasma and peritoneal fluid. Ninety women were evaluated, of whom 57 were confirmed as having endometriosis. Lactoferrin was measured by ELISA, transferrin, ferritin and iron on a Cobas 8000 analyser. Lactoferrin and transferrin in peritoneal fluid were lower compared to plasma, in contrast to ferritin and iron. In plasma, lactoferrin showeds associations with iron and transferrin in endometriosis and with ferritin in the group without endometriosis. Lactoferrin in peritoneal fluid correlated with lactoferrin, iron and transferrin of plasma in patients without endometriosis. The ratio of lactoferrin concentration in peritoneal fluid to plasma differentiated stage I versus IV of endometriosis and was negatively correlated with the iron ratio in patients without endometriosis. The ferritin ratio differentiated women with and without endometriosis. The very high ferritin ratios, especially in advanced stages of endometriosis, suggest the protective involvement of this protein in peritoneal fluid and the loss of this role by lactoferrin. The results demonstrate the validity of assessing iron metabolism in women with endometriosis, which may be useful as a marker of the disease and its progression.

Plasma and Peritoneal Fluid Fibronectin and Collagen IV Levels as Potential Biomarkers of Endometriosis.

Laparoscopy as a diagnostic tool for patients with suspected endometriosis is associated with several potentially life-threatening complications. Therefore, it is imperative to identify reliable, non-invasive biomarkers of the disease. The aim of this study was to analyse the concentrations of fibronectin and type IV collagen in peritoneal fluid and plasma to assess their role as potential biomarkers in the diagnosis of endometriosis. Fibronectin and collagen IV protein levels were assessed by surface plasmon resonance imaging (SPRi) biosensors with the usage of monoclonal antibodies. All patients enrolled in the study were referred for laparoscopy for the diagnosis of infertility or chronic pelvic pain (n = 84). The study group included patients with endometriosis confirmed during surgery (n = 49). The concentration of fibronectin in the plasma (329.3 ± 98.5 mg/L) and peritoneal fluid (26.8 ± 11.1 µg/L) in women with endometriosis was significantly higher than in the control group (251.2 ± 84.0 mg/L, 7.0 ± 5.9 µg/L). Fibronectin levels were independent of endometriosis stage (p = 0.874, p = 0.469). No significant differences were observed in collagen IV levels (p = 0.385, p = 0.465). The presence of elevated levels of fibronectin may indicate abnormalities in cell-ECM signalling during the course of endometriosis, and may be a potential biomarker for early detection.

Plasma and Peritoneal Poly (ADP-Ribose) Polymerase Levels in Patients with Endometriosis.

The evidence of poly (ADP-ribose) polymerase (PARP) association with the immune response could be coherent with the immunological theory of endometriosis and suggests the possibility of a new research direction. The aim of the study was to evaluate the levels of PARP in plasma and peritoneal fluid of patients with and without endometriosis. It was a multicenter, cross-sectional study. Plasma and peritoneal fluid samples were collected from patients with and without endometriosis during planned laparoscopic procedures in eight clinical centers. In total, 84 samples of plasma and 84 samples of the peritoneal fluid were included in the final analyses. Double-antibody sandwich enzyme-linked immunosorbent assay was performed in order to assess levels of PARP in collected samples. No statistically significant differences regarding the detected levels of PARP in plasma and peritoneal fluid comparing patients with and without endometriosis were observed. Patients with a history of infertility had significantly higher plasma PARP concentrations (p = 0.04). We have not observed the potential role of PARP concentration levels in plasma nor peritoneal fluid as an endometriosis biomarker. We have determined an association between a higher plasma PARP concentration and a history of infertility.

Plasma and Peritoneal Fluid ZEB Levels in Patients with Endometriosis and Infertility.

Zinc finger E-box-binding homeobox 1 (ZEB1) and zinc finger E-box-binding homeobox 2 (ZEB2) are transcription factors that regulate epithelial−mesenchymal transformation (EMT). The aim of this study was to compare levels of ZEB1 and ZEB2 in the peritoneal fluid and plasma between patients with and without endometriosis in order to assess their utility in the diagnostic process. Plasma and peritoneal fluid samples were collected from 50 patients with and 48 without endometriosis during planned surgical procedures in eight clinical centers. Quantitative ZEB1 and ZEB2 levels analyses were performed using a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). No significant differences were observed in ZEB1 levels in any of the subanalyses nor any differences regarding ZEB2 levels between patients with and without endometriosis. Plasma ZEB2 levels were significantly higher among patients with infertility compared to fertile women (16.07 ± 12.70 ng/L vs. 12.07 ± 11.92 ng/L; p < 0.04). Both ZEB1 and ZEB2 do not seem to have a significant value in the initial diagnosis of endometriosis as a single marker. The differences in ZEB2 plasma levels between patients with and without infertility indicate the possibility of EMT dysregulation in the pathogenesis of adverse fertility outcomes.

The Role of Cadherin 12 (CDH12) in the Peritoneal Fluid among Patients with Endometriosis and Endometriosis-Related Infertility.

Cadherin 12 (CDH 12) can play a role in the pathogenesis of endometriosis. The aim of this study was to compare the levels of cadherin 12 in the peritoneal fluid between women with and without endometriosis. This was a multicenter cross-sectional study. Eighty-two patients undergoing laparoscopic procedures were enrolled in the study. Cadherin 12 concentrations were determined using the enzyme-linked immunosorbent assay. The level of statistical significance was set at p < 0.05. No differences in cadherin 12 concentrations between patients with and without endometriosis were observed (p = 0.4). Subgroup analyses showed that CDH 12 concentrations were significantly higher in patients with infertility or primary infertility and endometriosis in comparison with patients without endometriosis and without infertility or primary infertility (p = 0.02) and also higher in patients with stage I or II endometriosis and infertility or primary infertility than in patients without endometriosis and infertility or primary infertility (p = 0.03, p = 0.048, respectively). In total, CDH 12 levels were significantly higher in patients diagnosed with infertility or primary infertility (p = 0.0092, p = 0.009, respectively) than in fertile women. Cadherin 12 can possibly play a role in the pathogenesis of infertility, both in women with and without endometriosis.

Planning and preparation for pregnancy among women with and without a history of infertility.

OBJECTIVES: Preconception counseling, maternal health-related habits, diet, folic acid consumption, substances abuse, may all impact the outcome of pregnancy. The aim of this study was to compare the planning and preparation for pregnancy among pregnant women with and without infertility. MATERIAL AND METHODS: A survey of health behaviors prior to and during pregnancy that could affect pregnancy outcomes, including laboratory tests performed, stimulant usage, initiation of prenatal care, and folic acid intake, was conducted among 400 pregnant women. The study group included 121 women (30.25%) diagnosed with prior infertility, while the control group included 279 women (69.74%) who did not report any problems conceiving. RESULTS: All patients (100%) from the study group and 70,97% from the control group planned their pregnancy(p < 0.0001). Patients in the study group performed significantly more laboratory tests prior to pregnancy, including: complete blood count, urine analysis, fasting blood glucose concentration, testing for toxoplasmosis, and Pap smear, compared with the control group (p < 0.0001). There was no difference between groups regarding the knowledge of when and why folic acid supplementation is required (p > 0.05). CONCLUSIONS: Effective education of women, regarding pregnancy planning and behaviours, that may impact pregnancy outcome is still a serious challange to public health in Poland. Our study indicates that reaching general population with the education is most important to achieve best results in preconceptional care.