Serum YKL-40 levels are altered in endometriosis

State-of-the-art and future perspectives in infertility diagnosis: Conventional versus nanotechnology-based assays

According to the latest World Health Organization statistics, around 50 to 80 million people worldwide suffer from infertility, amongst which male factors are responsible for around 20 to 30 % of all infertility cases while 50 % were attributed to the female ones. As it is becoming a recurrent health problem worldwide, clinicians require more accurate methods for the improvement of both diagnosis and treatment schemes. By emphasizing the potential use of innovative methods for the rapid identification of the infertility causes, this review presents the news from this dynamic domain and highlights the benefits brought by emerging research fields. A systematic description of the standard techniques used in clinical protocols for diagnosing infertility in both genders is firstly provided, followed by the presentation of more accurate and comprehensive nanotechnology-related analysis methods such as nanoscopic-resolution imaging, biosensing approaches and assays that employ nanomaterials in their design. Consequently, the implementation of nanotechnology related tools in clinical practice, as recently demonstrated in the selection of spermatozoa, the detection of key proteins in the fertilization process or the testing of DNA integrity or the evaluation of oocyte quality, might confer excellent advantages both for improving the assessment of infertility, and for the success of the fertilization process.

The Abundance and Function of Neutrophils in the Endometriosis Systemic and Pelvic Microenvironment

Endometriosis is a common inflammatory illness in which endometrial tissue grows outside the uterine cavity. Immune dysfunction is now widely acknowledged as the primary cause of endometriosis. The immune cell population represented by neutrophils is thought to play an essential role in the etiology, pathophysiology, and associated clinical outcome. There is growing evidence that neutrophils have a role in chronic and aseptic inflammatory diseases, and endometriosis patients have increased levels of neutrophils in plasma, peritoneal fluid, and ectopic endometrium. Here, we sought to review the function of neutrophils in the pathogenesis of endometriosis, with an emphasis on the role of neutrophils in regulating endometrial angiogenesis and the local inflammatory microenvironment.

Resistin and chemerin levels in follicular fluid of infertile women with endometriosis undergoing ICSI

Chemerin and resistin are two adipocytokines involved in inflammatory processes that may paly a role in the development of endometriosis. The purpose of the current study was to examine the levels of chemerin and resistin in the follicular fluid (FF) of endometriosis patients and additionally, assess the association of FF chemerin and resistin with the severity of endometriosis and the number of mature oocyte and embryos. A total of 80 reproductive-aged women who underwent intracytoplasmic sperm injection and embryo transfer were evaluated in this study. FF samples were obtained from subjects with (n = 40) and without endometriosis (n = 40). The concentrations of chemerin and resistin were examined using ELISA. The Resistin FF level was significantly (p-value=.03) higher in women with endometriosis than women without endometriosis, while the effect size was medium (d = 0.47). There was no significant difference in Chemerin concentration between the two groups of this study. Results also showed a tendency towards the increase of FF values of resistin and chemerin in endometriosis patients with stage III-IV than stage I-II; however, this difference was not significant. No significant correlations were found between FF levels of resistin and chemerin with the number of mature oocyte and embryos. Thus, elevated FF resistin levels may be associated with endometriosis.IMPACT STATEMENTWhat is already known on this subject? To our knowledge, no studies have investigated chemerin levels in follicular fluid of infertile women with endometriosis undergoing ICSI. Although follicular fluid levels of resistin have been previously studied in endometriosis, it has not been studied yet whether its level is associated with the number of oocyte and embryos.What do the results of this study add? Our results indicate that significantly increased resistin levels in follicular fluid may be associated with the presence of endometriosis.What are the implications of these findings for clinical practice and/or further research? The findings are promising in that significantly increased resistin levels may add to the knowledge of the pathophysiology of endometriosis.

Diagnostic Significance of Selected Serum Inflammatory Markers in Women with Advanced Endometriosis

Endometriosis is a gynecological disease, the pathogenesis of which seems to be directly associated with inflammatory processes. Serum concentrations of IL-1β, IL-6, hs-CRP, IgG, YKL 40 and PRL, in comparison to the well-known CA 125 levels, were studied with the aim of identifying an additional noninvasive inflammatory marker or set of markers characteristic for endometriosis. The study group included 43 women with endometriosis (E), 35 women with benign gynecological disorders but without endometriosis (NE, non-endometriosis) as a comparative group, and a control group consisting of 18 healthy subjects (C). The serum concentrations of IL-1β, IL-6, hs-CRP, YKL-40, PRL and CA 125 were significantly higher in the E group (median values: 0.41 pg/mL, 2.42 pg/mL, 2.33 mg/L, 79.30 ng/mL, 21.88 ng/mL and 68.00 U/mL, respectively) than in the control group (median values: 0.21 pg/mL, 0.98 pg/mL, 0.52 mg/L, 49.77 ng/mL, 12.08 ng/mL and 12.20 U/mL respectively), with the significance of p = 0.011, p < 0.001, p = 0.028, p = 0.005, p < 0.001 and p < 0.001, respectively. The IgG concentrations were significantly lower in the endometriosis group (median value: 1061.21 mg/dL) as compared to healthy women (median value: 1210.50 mg/dL; p = 0.025). Significant differences in concentrations of IL-6 (p = 0.040), hs-CRP (p = 0.007) and CA 125 (p < 0.001) were observed in stage III vs. stage IV of endometriosis. Significantly higher concentrations of IL-6 (p = 0.010), hs-CRP (p = 0.037) and PRL (p < 0.001) were observed in the NE group vs. the control group. Only CA 125 concentrations were significantly higher in endometriosis patients as compared to the non-endometriosis group (p < 0.001). The proposed panel of inflammatory markers, especially IL-6, PRL and CA 125, may become a useful tool to identify women with advanced endometriosis who could qualify for treatment.

Non-invasive diagnosis of endometriosis and moderate-severe endometriosis with serum CA125, endocan, YKL-40, and copeptin quadruple panel

Considering the complex pathogenesis of endometriosis, which is associated with many cellular or molecular processes, such as proliferation, angiogenesis, inflammation, we evaluated the diagnostic value of a quadruple panel of serum markers CA125, endocan, YKL-40 and copeptin, for the prediction of endometriosis and moderate - severe endometriosis. Seventy women with endometriosis and 70 women without endometriosis were evaluated. Serum CA125, endocan, copeptin and YKL-40 levels were significantly increased in women with endometriosis compared to the women without endometriosis and in the minimal - mild endometriosis group compared to the no-endometriosis group. YKL-40, endocan and copeptin levels were significantly increased in the moderate - severe endometriosis group compared to the mild -moderate endometriosis group but the difference in CA125 levels remained non-significant. The quadruple panel score had an AUC of 0.954, a sensitivity of 96.5% and specificity of 84.6% for prediction of moderate - severe endometriosis. Zero or one positive marker had a sensitivity of 91.4% and specificity of 88.57% to rule out endometriosis. In conclusion, a quadruple panel of serum markers-CA125, endocan, YKL-40, and copeptin may be beneficial for the diagnosis of endometriosis and especially moderate - severe endometriosis. Further studies are needed to prove the efficacy of this panel.Impact statementWhat is already known on this subject? Many serum markers including CA125 have been investigated so far and suggested to be associated with endometriosis. However, none of these markers is sensitive and specific enough to diagnose endometriosis.What do the results of this study add? A quadruple panel score (CA125, endocan, YKL-4 and copeptin) had an AUC of 0.954, a sensitivity of 96.5% and specificity of 84.6% for prediction of moderate - severe endometriosis.What are the implications of these findings for clinical practice and/or further research? A high score may be beneficial to warn the surgeon about the risk of moderate to severe endometriosis if the patient will be operated anyway. A negative test of the quadruple panel may show high odds that there is no endometriosis which may prevent unnecessary surgery.

Blood biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women 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 or minimally invasive tests available in clinical practice to accurately diagnose endometriosis. Although other reviews have assessed the ability of blood tests to diagnose endometriosis, this is the first review to use Cochrane methods, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To evaluate blood biomarkers as replacement tests for diagnostic surgery and as triage tests to inform decisions on surgery for endometriosis. Specific objectives include:1. To provide summary estimates of the diagnostic accuracy of blood biomarkers for the diagnosis of peritoneal, ovarian and deep infiltrating 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.

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 these databases to 20 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 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 blood biomarkers with the findings of surgical visualisation of endometriotic lesions.

DATA COLLECTION AND ANALYSIS

Two authors independently collected and performed a quality assessment of data from each study. For each diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis, and we calculated sensitivity and specificity estimates. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient datasets were available. The predetermined criteria for a clinically useful blood 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 a specificity of ≥ 0.50, which 'rules out' the diagnosis with high accuracy if there is a negative test result (SnOUT test), or a sensitivity of ≥ 0.50 and a specificity of ≥ 0.95, which 'rules in' the diagnosis with high accuracy if there is a positive result (SpIN test).

MAIN RESULTS

We included 141 studies that involved 15,141 participants and evaluated 122 blood biomarkers. All the studies were of poor methodological quality. Studies evaluated the blood biomarkers either in a specific phase of the menstrual cycle or irrespective of the cycle phase, and they tested for them in serum, plasma or whole blood. Included women were a selected population with a high frequency of endometriosis (10% to 85%), in which surgery was indicated for endometriosis, infertility work-up or ovarian mass. Seventy studies evaluated the diagnostic performance of 47 blood biomarkers for endometriosis (44 single-marker tests and 30 combined tests of two to six blood biomarkers). These were angiogenesis/growth factors, apoptosis markers, cell adhesion molecules, high-throughput markers, hormonal markers, immune system/inflammatory markers, oxidative stress markers, microRNAs, tumour markers and other proteins. Most of these biomarkers were assessed in small individual studies, often using different cut-off thresholds, and we could only perform meta-analyses on the data sets for anti-endometrial antibodies, interleukin-6 (IL-6), cancer antigen-19.9 (CA-19.9) and CA-125. Diagnostic estimates varied significantly between studies for each of these biomarkers, and CA-125 was the only marker with sufficient data to reliably assess sources of heterogeneity.The mean sensitivities and specificities of anti-endometrial antibodies (4 studies, 759 women) were 0.81 (95% confidence interval (CI) 0.76 to 0.87) and 0.75 (95% CI 0.46 to 1.00). For IL-6, with a cut-off value of > 1.90 to 2.00 pg/ml (3 studies, 309 women), sensitivity was 0.63 (95% CI 0.52 to 0.75) and specificity was 0.69 (95% CI 0.57 to 0.82). For CA-19.9, with a cut-off value of > 37.0 IU/ml (3 studies, 330 women), sensitivity was 0.36 (95% CI 0.26 to 0.45) and specificity was 0.87 (95% CI 0.75 to 0.99).Studies assessed CA-125 at different thresholds, demonstrating the following mean sensitivities and specificities: for cut-off > 10.0 to 14.7 U/ml: 0.70 (95% CI 0.63 to 0.77) and 0.64 (95% CI 0.47 to 0.82); for cut-off > 16.0 to 17.6 U/ml: 0.56 (95% CI 0.24, 0.88) and 0.91 (95% CI 0.75, 1.00); for cut-off > 20.0 U/ml: 0.67 (95% CI 0.50 to 0.85) and 0.69 (95% CI 0.58 to 0.80); for cut-off > 25.0 to 26.0 U/ml: 0.73 (95% CI 0.67 to 0.79) and 0.70 (95% CI 0.63 to 0.77); for cut-off > 30.0 to 33.0 U/ml: 0.62 (95% CI 0.45 to 0.79) and 0.76 (95% CI 0.53 to 1.00); and for cut-off > 35.0 to 36.0 U/ml: 0.40 (95% CI 0.32 to 0.49) and 0.91 (95% CI 0.88 to 0.94).We could not statistically evaluate other biomarkers meaningfully, including biomarkers that were assessed for their ability to differentiate endometrioma from other benign ovarian cysts.Eighty-two studies evaluated 97 biomarkers that did not differentiate women with endometriosis from disease-free controls. Of these, 22 biomarkers demonstrated conflicting results, with some studies showing differential expression and others no evidence of a difference between the endometriosis and control groups.

AUTHORS' CONCLUSIONS

Of the biomarkers that were subjected to meta-analysis, none consistently met the criteria for a replacement or triage diagnostic test. A subset of blood biomarkers could prove useful either for detecting pelvic endometriosis or for differentiating ovarian endometrioma from other benign ovarian masses, but there was insufficient evidence to draw meaningful conclusions. Overall, none of the biomarkers displayed enough accuracy to be used clinically outside a research setting. We also identified blood biomarkers that demonstrated no diagnostic value in endometriosis and recommend focusing research resources on evaluating other more clinically useful biomarkers.

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.