Evaluation of elevated urinary enolase I levels in patients with endometriosis

Deciphering the potential of proteomic-based biomarkers in women's reproductive diseases: empowering precision medicine in gynecology

CONTEXT

Gynecological disorders represent a complex set of malignancies that result from a diverse array of molecular changes affecting the lives of over a million women worldwide. Ovarian, Endometrial, and Cervical cancers, Endometriosis, PCOS are the most prevalent ones that pose a grave threat to women's health. Proteomics has emerged as an invaluable tool for developing novel biomarkers, screening methods, and targeted therapeutic agents for gynecological disorders. Some of these biomarkers have been approved by the FDA, but regrettably, they have a constrained diagnostic accuracy in early-stage diagnosis as all of these biomarkers lack sensitivity and specificity. Lately, high-throughput proteomics technologies have made significant strides, allowing for identification of potential biomarkers with improved sensitivity and specificity. However, limited successes have been shown with translation of these discoveries into clinical practice.

OBJECTIVE

This review aims to provide a comprehensive overview of the current and potential protein biomarkers for gynecological cancers, endometriosis and PCOS, discusses recent advances and challenges, and highlights future directions for the field.

CONCLUSION

We propose that proteomics holds great promise as a powerful tool to revolutionize the fight against female reproductive diseases and can ultimately improve personalized patient outcomes in women's biomedicine.

Diagnostic significance of neutrophil to lymphocyte ratio in endometriosis: a systematic review and meta-analysis

BACKGROUND

The purpose of this systematic review and meta-analysis was to compile existing evidence on the significance of the NLR in predicting endometriosis in order to aid clinical decision-making and outcomes.

METHODS

We searched ProQuest, Web of Science, and PubMed for related studies published before January 2, 2023. Standardized mean difference (SMD) with a 95% confidence interval (CI) was reported for each outcome. Because a significant level of heterogeneity was found, we used the random-effects model to calculate pooled effects. We used Newcastle-Ottawa Scale (NOS) for quality assessment.

RESULTS

Overall, 18 article with were included in the analysis. A random-effect model revealed that patients with endometriosis had elevated levels of NLR compared to healthy controls (SMD = 0.79, 95% CI = 0.33 to 1.25, P < 0.001). Patients with endometriosis had elevated levels of NLR compared to those with other benign tumors (SMD = 0.85, 95% CI = 0.17 to 1.53, P = 0.014). In addition, NLR level of patients with stage III and IV endometriosis was not different from that of patients with stage I and II endometrioma (SMD = 0.30, 95% CI = -0.14 to 0.74, P = 0.18). However, NLR level was not different between endometriosis patients with and without peritoneal lesions (SMD = -0.12, 95% CI = -0.34to 0.10, P = 0.28), between patients with and without endometrioma (SMD = 0.20, 95% CI = -0.15 to 0.55, P = 0.26) and between endometriosis patients with and without deep lesions (SMD = 0.04, 95% CI = -0.20 to 0.28, P = 0.72). The pooled sensitivity of NLR was 0.67 (95% CI = 0.60-0.73), and the pooled specificity was 0.68 (95% CI, 0.62-0.73).

CONCLUSIONS

NLR might be utilized in clinics as a possible predictor to help clinicians diagnose endometriosis in affected women.

Biomarkers of endometriosis

Endometriosis is one of the most severe female reproductive disorders, affecting 6-10% of women between 18 and 35. It is a gynaecological condition where endometrial tissue develops and settles outside the uterus. The aetiology of endometriosis is primarily influenced by genetic, epigenetic, and non-genetic variables, making it highly challenging to create a therapeutic therapy explicitly targeting the ectopic tissue. The delay in the treatment is due to the limitations in the diagnostic approaches, which are restricted to invasive techniques such as laparoscopy or laparotomy. This accords to 70% of the women being diagnosed at later stages. By understanding the subject, several treatment medications have been produced to lessen the disease's symptoms. Nevertheless, endometriosis cannot be permanently cured. A viable or persuasive standard screening test for endometriosis must be utilized in a clinical context. A helpful assessment method for the early identification of endometriosis could be biomarkers. A major research priority is the identification of a biomarker that is sensitive and specific enough for detecting endometriosis. The present article has reviewed studies published on the expression of biomarkers of endometriosis. It outlines various biomarkers from different sample types, such as serum/plasma and urine, in addition to tissue. This would provide a non-invasive approach to diagnosing the disease at the initial stages without any harmful repercussions. Future high-throughput advances in science and technology are anticipated to result in the creation of a potent remedy for endometriosis. To achieve successful outcomes, it is necessary to research the discussed biomarkers that demonstrate substantial results extensively.

Urinary Biomarkers for Detection of Clinical Endometriosis or Adenomyosis

Endometriosis or adenomyosis can be clinically diagnosed by ultrasound, symptoms, physical examination, and serum CA125. The urinary markers need to be investigated. The aim of our study was to investigate the urinary markers of clinical endometriosis/adenomyosis, and the correlation of serum CA125 was also studied. From the literature, alpha-1 antitrypsin (A1AT), enolase-1, vitamin D binding protein (VDBP), and CA125 in urine and serum were used in our study and measured by enzyme-linked immunosorbent assays (ELISA). Further clinical correlation and detection performance were evaluated. We enrolled 19 normal controls and 33 patients clinically diagnosed with endometriosis/adenomyosis. There were significant differences between studied patients and normal controls, as follows: serum CA125 (130.91 vs. 19.75 U/mL, p = 0.004); urinary CA125-creatinine ratio (5.591 vs. 0.254 ng/mg, p = 0.028); and urinary VDBP-creatinine ratio (28.028 vs. 7.301 ng/mg, p = 0.018). For diagnostic performances, serum CA125 provided the best results, with an area under curve (AUC) of 0.888 (p = 0.001) and accuracy of 86.5%. Other excellent results were also found using urinary VDBP (AUC 0.841, p = 0.001) and A1AT (AUC 0.722, p = 0.011) creatinine ratio. Using three combined biomarkers, serum CA125, urinary VDBP, and A1AT creatinine ratio, provided good detection power (AUC 0.913, p = 0.001, sensitivity 90.9%, specificity 76.5%). Double urine markers used in combination with VDBP and A1AT creatinine ratio also provided good diagnostic performance (AUC 0.809, p = 0.001, sensitivity 81.8%, specificity 76.5%, accuracy 80%). Further development of non-invasive point-of-care tests using these biomarkers could be a fruitful future endeavor.

The diagnostic value of the combination of hemoglobin, CA199, CA125, and HE4 in endometriosis

BACKGROUND

We aimed to analyze the differences in the peripheral blood cells and tumor biomarkers between the patients with endometriosis and healthy people, and establish a more efficient combined diagnostic model.

METHODS

We retrospectively analyzed the differences in the peripheral blood cells and tumor biomarkers between the patients with endometriosis and healthy people. Binary logistic regression analysis was used to establish a combined diagnostic model. We plotted the receiver operator characteristic (ROC) curve to analyze the diagnostic efficiency of different diagnostic indexes.

RESULTS

Compared with patients in the control group, patients in the endometriosis group had significantly lower eosinophil% (p = 0.045), neutrophil (p = 0.001), lymphocyte (p < 0.001), red blood cells (RBCs) (p < 0.001), and hemoglobin (HGB) (p < 0.001), and had significantly higher monocyte% (p = 0.008), monocyte-to-lymphocyte ratio (MLR) (p = 0.001), platelet-to-lymphocyte ratio (PLR) (p < 0.001), carbohydrate antigen (CA)-199 (p < 0.001), CA125 (p < 0.001), human epididymis protein (HE)-4 (p < 0.001), and the risk of ovarian malignancy algorithm (ROMA) (p < 0.001). The combined diagnostic model of HGB, CA199, CA125, and HE4 was established by binary logistic regression analysis. The ROC curve showed that the combined diagnostic model reached a sensitivity of 85.4%, a specificity of 78.83%, and an area under the curve of 0.900, which was significantly higher than that of the individual index in endometriosis diagnosis.

CONCLUSION

The combined diagnostic model of HGB, CA199, CA125, and HE4 may provide a new approach for the early non-invasive diagnosis of endometriosis.

The Potential of Non-Invasive Biomarkers for Early Diagnosis of Asymptomatic Patients with Endometriosis

Endometriosis is a disease that affects women of reproductive age and has a significantly negative impact on their well-being. The main symptoms are dysmenorrhoea, chronic pelvic pain and infertility. In many patients the diagnostic process is very long and can take up to 8-12 years. Laparoscopy, an invasive method, is still necessary to confirm the diagnosis. Therefore, development of more effective diagnostic markers appears to be of the utmost importance for early diagnosis of endometriosis and provision of appropriate treatment. From a clinical point of view, detection of early-stage endometriosis in asymptomatic patients is an ideal situation since early diagnosis of endometriosis may delay the onset of symptoms as well as prevent progression and complications. In the meantime, Cancer Antigen 125 (CA-125) is still the most frequently studied and used marker. Other glycoproteins, growth factors and immune markers seem to play an important role. However, the search for an ideal endometriosis marker is still underway. Further studies into the pathogenesis of endometriosis will help to identify biomarkers or sets of biomarkers with the potential to improve and speed up the diagnostic process in a non-invasive way.

Current biomarkers for the detection of endometriosis

A clinically reliable non-invasive test for endometriosis is expected to reduce the diagnostic delay. Although varieties of biomarkers have been investigated for decades, and cancer antigen-125, cancer antigen-199, interleukin-6, and urocortin were the most studied ones among hundreds of biomarkers, no clinically reliable biomarkers have been confirmed so far. Some emerging technologies including “omics” technologies, molecular imaging techniques, and microRNAs are promising in solving these challenges, but their utility to detect endometriosis has yet to be verified. New combinations of researched indicators or other non-invasive methods and further exploration of the emerging technologies may be new targets and future research hotspots for non-invasive diagnosis of endometriosis. In conclusion, researches of biomarkers for the detection of endometriosis are still ongoing and may benefit from novel molecular biology, bioinformatics methods and a combination of more diverse monitoring methods. Though it will be a daunting task, the identification of a specific set of diagnostic biomarkers will undoubtedly improve the status of endometriosis.

The Diagnostic Accuracy of Combined Enolase/Cr, CA125, and CA19-9 in the Detection of Endometriosis

Background

The present study was designed to verify the accuracy of the noninvasive biomarkers enolase/Cr, CA125, and CA19-9 as a clinical diagnostic tool for the detection of endometriosis.

Methods

A cross-sectional study was performed at Rasool-e-Akram Hospital affiliated to Iran University of Medical Sciences, Tehran, Iran, from April 2015 to April 2018. Eighty-six women were scheduled to undergo laparoscopy due to chronic pelvic pain, infertility, pelvic mass, and abnormal uterine bleeding. Serum and urine samples of all patients were collected preoperatively. Serum levels of CA125 and CA19-9, and urine levels of enolase-1 were measured. Serum levels of CA125 and CA19-9 were determined by the electrochemiluminescence method (ECL). Urinary enolase-1 was measured by the ELISA method.

Result

Serum levels of CA125 and CA19-9 were significantly higher in the endometriosis group than in controls (p < 0.001, p = 0.004, respectively). Levels of enolase I and enolase/Cr were higher in patients with endometriosis, but the differences were not statistically significant. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of combined enolase/Cr, CA125, and CA19-9 were 65%, 66.6%, 71%, and 60.1%, respectively. The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of combined enolase/Cr, CA125, and CA19-9 was 1.94 and 0.52, respectively. The area under the ROC curve for enolase/Cr + CA125 + CA19 - 9 was 0.675 (95% confidence interval 0.573-0.710).

Conclusion

The present study revealed that concurrent measurement of enolase-1, CA125, and CA19-9 might be a valuable noninvasive test for the identification of endometriosis.

Combination of the non-invasive tests for the diagnosis of endometriosis

BACKGROUND

About 10% of women of reproductive age suffer from endometriosis, a costly chronic disease causing pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice to accurately diagnose endometriosis. This review assessed the diagnostic accuracy of combinations of different non-invasive testing modalities for endometriosis and provided a summary of all the reviews in the non-invasive tests for endometriosis series.

OBJECTIVES

To estimate the diagnostic accuracy of any combination of non-invasive tests for the diagnosis of pelvic endometriosis (peritoneal and/or ovarian or deep infiltrating) compared to surgical diagnosis as a reference standard. The combined tests were evaluated as replacement tests for diagnostic surgery and triage tests to assist decision-making to undertake diagnostic surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. We searched CENTRAL to July 2015, MEDLINE and EMBASE to May 2015, as well as the following databases to April 2015: CINAHL, PsycINFO, Web of Science, LILACS, OAIster, TRIP, ClinicalTrials.gov, DARE and PubMed.

SELECTION CRITERIA

We considered published, peer-reviewed, randomised controlled or cross-sectional studies of any size, including prospectively collected samples from any population of women of reproductive age suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE). We included studies comparing the diagnostic test accuracy of a combination of several testing modalities with the findings of surgical visualisation of endometriotic lesions.

DATA COLLECTION AND ANALYSIS

Three review authors independently collected and performed a quality assessment of the data from each study by using the QUADAS-2 tool. For each test, the data were classified as positive or negative for the surgical detection of endometriosis and sensitivity and specificity estimates were calculated. The bivariate model was planned to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery were a sensitivity of 0.94 and a specificity of 0.79 to detect endometriosis. We set the criteria for triage tests at a sensitivity of 0.95 and above and a specificity of 0.50 and above, which 'rules out' the diagnosis with high accuracy if there is a negative test result (SnOUT test), or a sensitivity of 0.50 and above and a specificity of 0.95 and above, which 'rules in' the diagnosis with high accuracy if there is a positive result (SpIN test).

MAIN RESULTS

Eleven eligible studies included 1339 participants. All the studies were of poor methodological quality. Seven studies evaluated pelvic endometriosis, one study considered DIE and/or ovarian endometrioma, two studies differentiated endometrioma from other ovarian cysts and one study addressed mapping DIE at specific anatomical sites. Fifteen different diagnostic combinations were assessed, including blood, urinary or endometrial biomarkers, transvaginal ultrasound (TVUS) and clinical history or examination. We did not pool estimates of sensitivity and specificity, as each study analysed independent combinations of the non-invasive tests.Tests that met the criteria for a replacement test were: a combination of serum IL-6 (cut-off >15.4 pg/ml) and endometrial PGP 9.5 for pelvic endometriosis (sensitivity 1.00 (95% confidence interval (CI) 0.91 to 1.00), specificity 0.93 (95% CI, 0.80, 0.98) and the combination of vaginal examination and transvaginal ultrasound (TVUS) for rectal endometriosis (sensitivity 0.96 (95% CI 0.86 to 0.99), specificity 0.98 (95% CI 0.94 to 1.00)). Tests that met the criteria for SpIN triage tests for pelvic endometriosis were: 1. a multiplication of urine vitamin-D-binding protein (VDBP) and serum CA-125 (cut-off >2755) (sensitivity 0.74 (95% CI 0.60 to 0.84), specificity 0.97 (95% CI 0.86 to 1.00)) and 2. a combination of history (length of menses), serum CA-125 (cut-off >35 U/ml) and endometrial leukocytes (sensitivity 0.61 (95% CI 0.54 to 0.69), specificity 0.95 (95% CI 0.91 to 0.98)). For endometrioma, the following combinations qualified as SpIN test: 1. TVUS and either serum CA-125 (cut-off ≥25 U/ml) or CA 19.9 (cut-off ≥12 U/ml) (sensitivity 0.79 (95% CI 0.64 to 0.91), specificity 0.97 (95% CI 0.91 to 1.00)); 2. TVUS and serum CA 19.9 (cut-off ≥12 U/ml) (sensitivity 0.54 (95% CI 0.37 to 0.70), specificity 0.97 (95% CI 0.91 to 1.0)); 3-4. TVUS and serum CA-125 (cut-off ≥20 U/ml or cut-off ≥25 U/ml) (sensitivity 0.69 (95% CI 0.49 to 0.85), specificity 0.96 (95% CI 0.88 to 0.99)); 5. TVUS and serum CA-125 (cut-off ≥35 U/ml) (sensitivity 0.52 (95% CI 0.33 to 0.71), specificity 0.97 (95% CI 0.90 to 1.00)). A combination of vaginal examination and TVUS reached the threshold for a SpIN test for obliterated pouch of Douglas (sensitivity 0.87 (95% CI 0.69 to 0.96), specificity 0.98 (95% CI 0.95 to 1.00)), vaginal wall endometriosis (sensitivity 0.82 (95% CI 0.60 to 0.95), specificity 0.99 (95% CI 0.97 to 1.0)) and rectovaginal septum endometriosis (sensitivity 0.88 (95% CI 0.47 to 1.00), specificity 0.99 (95% CI 0.96 to 1.00)).All the tests were evaluated in individual studies and displayed wide CIs. Due to the heterogeneity and high risk of bias of the included studies, the clinical utility of the studied combination diagnostic tests for endometriosis remains unclear.

AUTHORS' CONCLUSIONS

None of the biomarkers evaluated in this review could be evaluated in a meaningful way and there was insufficient or poor-quality evidence. Laparoscopy remains the gold standard for the diagnosis of endometriosis and using any non-invasive tests should only be undertaken in a research setting.

Urinary biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis which is a costly chronic disease that causes pelvic pain and subfertility. Laparoscopy is the 'gold standard' diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no simple non-invasive or minimally-invasive tests available in clinical practice that accurately diagnoses endometriosis.

OBJECTIVES

1. To provide summary estimates of the diagnostic accuracy of urinary biomarkers for the diagnosis of pelvic endometriosis compared to surgical diagnosis as a reference standard.2. To assess the diagnostic utility of biomarkers that could differentiate ovarian endometrioma from other ovarian masses.Urinary biomarkers were evaluated as replacement tests for surgical diagnosis and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

The searches were not restricted to particular study design, language or publication dates. We searched the following databases to 20 April - 31 July 2015: CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, LILACS, OAIster, TRIP and ClinicalTrials.gov (trial register). MEDION, DARE, and PubMed were also searched to identify reviews and guidelines as reference sources of potentially relevant studies. Recently published papers not yet indexed in the major databases were also sought. The search strategy incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH) and was modified for each database.

SELECTION CRITERIA

Published peer-reviewed, randomised controlled or cross-sectional studies of any size were considered, which included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE). We included studies comparing the diagnostic test accuracy of one or more urinary biomarkers with surgical visualisation of endometriotic lesions.

DATA COLLECTION AND ANALYSIS

Two authors independently collected and performed a quality assessment of the data from each study. For each diagnostic test, the data were classified as positive or negative for the surgical detection of endometriosis and sensitivity and specificity estimates were calculated. If two or more tests were evaluated in the same cohort, each was considered as a separate data set. The bivariate model was used to obtain pooled estimates of sensitivity and specificity whenever sufficient data sets were available. The predetermined criteria for a clinically useful urine test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79% to detect endometriosis. The criteria for triage tests were set at sensitivity of equal or greater than 95% and specificity of equal or greater than 50%, which in case of negative result rules out the diagnosis (SnOUT test) or sensitivity of equal or greater than 50% with specificity of equal or greater than 95%, which in case of positive result rules the diagnosis in (SpIN test).

MAIN RESULTS

We included eight studies involving 646 participants, most of which were of poor methodological quality. The urinary biomarkers were evaluated either in a specific phase of menstrual cycle or irrespective of the cycle phase. Five studies evaluated the diagnostic performance of four urinary biomarkers for endometriosis, including three biomarkers distinguishing women with and without endometriosis (enolase 1 (NNE); vitamin D binding protein (VDBP); and urinary peptide profiling); and one biomarker (cytokeratin 19 (CK 19)) showing no significant difference between the two groups. All of these biomarkers were assessed in small individual studies and could not be statistically evaluated in a meaningful way. None of the biomarkers met the criteria for a replacement test or a triage test. Three studies evaluated three biomarkers that did not differentiate women with endometriosis from disease-free controls.

AUTHORS' CONCLUSIONS

There was insufficient evidence to recommend any urinary biomarker for use as a replacement or triage test in clinical practice for the diagnosis of endometriosis. Several urinary biomarkers may have diagnostic potential, but require further evaluation before being introduced into routine clinical practice. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and diagnosis of endometriosis using urinary biomarkers should only be undertaken in a research setting.

Update on Biomarkers for the Detection of Endometriosis

Endometriosis is histologically characterized by the displacement of endometrial tissue to extrauterine locations including the pelvic peritoneum, ovaries, and bowel. An important cause of infertility and pelvic pain, the individual and global socioeconomic burden of endometriosis is significant. Laparoscopy remains the gold standard for the diagnosis of the condition. However, the invasive nature of surgery, coupled with the lack of a laboratory biomarker for the disease, results in a mean latency of 7–11 years from onset of symptoms to definitive diagnosis. Unfortunately, the delay in diagnosis may have significant consequences in terms of disease progression. The discovery of a sufficiently sensitive and specific biomarker for the nonsurgical detection of endometriosis promises earlier diagnosis and prevention of deleterious sequelae and represents a clear research priority. In this review, we describe and discuss the current status of biomarkers of endometriosis in plasma, urine, and endometrium.

Urine, peritoneal fluid and omental fat proteomes of reproductive age women: Endometriosis-related changes and associations with endocrine disrupting chemicals

Endometriosis, ectopic growth of the uterine lining (endometrium), which affects 6-11% of reproductive age women, is associated with pelvic pain and infertility. We investigated the peritoneal fluid (PF), urine and omental fat (OF) proteomes of women with endometriosis vs. individuals with no surgically visualized endometriosis. All participants were enrolled in the NICHD-funded ENDO Study. A two-step proteomic study was performed. The first, a broad survey, employed a semi-quantitative gel LC-mass spectrometry (MS) workflow: SDS PAGE fractionation, trypsin digestion and LC-MS/MS. The results showed sample integrity but failed to detect any differences between women with and without endometriosis. The second step was a quantitative analysis of OF samples. We employed another sample set (n=30) from women ± disease and isobaric mass-tag (iTRAQ) chemistry to label peptides and 2D LC-MS/MS for protein identification and quantification. Three proteins-matrix metalloproteinase-9, neutrophil elastase, and FAM49B-were significantly lower in abundance in samples from women with endometriosis. Interestingly, neutrophil elastase and FAM49B levels were associated with higher levels of a subset of endocrine disrupting chemicals (EDCs) that were previously measured in the same samples. The results of these experiments showed the feasibility of associating endometriosis with changes in the OF protein repertoire and EDC levels.

BIOLOGICAL SIGNIFICANCE

Endometriosis, pathological growth of the uterine lining, is associated with significant morbidities, including pain and infertility. However, the causes of this common condition are poorly understood. This study determined whether endometriosis was associated with changes in the protein composition of peritoneal fluid, urine and/or omental fat. A protein of unknown function (FAM49B) and two proteinases (metalloproteinase-9, neutrophil elastase) were down regulated in OF samples from women with versus without endometriosis. These findings suggested proteinase imbalances at sites that were distant from the endometriotic lesions. Additionally, FAM49B and neutrophil elastase levels were associated with higher levels of a subset of environmental chemicals that were quantified in the same samples, suggesting other possible associations. Thus, this work generated hypotheses that will be tested in further studies.