Association between PTPN22 and endometriosis

Reproductive Effect by Rheumatoid Arthritis and Related Autoantibodies

Rheumatoid arthritis (RA) is a common inflammatory arthritis in women. The effects of RA on the reproductive system are usually overlooked, as RA is not diagnosed until later in reproductive age. Whether RA itself or its related rheumatoid antibodies have an impact on female reproductive function has long been a thought-provoking issue. In brief, relevant epidemiological evidence has shown that women affected by RA are more likely to have coexisting reproductive disorders, including infertility, endometriosis, and premature ovarian insufficiency (POI), or to subsequently develop them. Furthermore, linkage between RA and pregnancy loss (PL) as well as polycystic ovary syndrome (PCOS) is also well known, albeit controversial in available evidence. RA and reproductive disorders appear to share a similar inflammatory immune response and genetic background. The stress experienced by patients with RA may affect their reproductive choices to some extent. Notably, few studies have explored the impact of rheumatoid antibodies such as rheumatoid factors (RFs) and anti-citrullinated protein antibodies (ACPAs) on reproductive disorders. Although it has been mentioned that the rate of RF and/or ACPA positivity is higher in women with a history of PL and POI, the clinical relevance of this relationship and underlying mechanisms still need to be further clarified.

Association of the protein tyrosine phosphatase non-receptor 22 polymorphism (PTPN22) with endometriosis: a meta-analysis

Objective

To evaluate PTPN22 C1858T polymorphism and the risk of endometriosis.

Methods

A meta-analysis of 10 published case-control studies (from four articles), with a total sample of 971 cases and 1,181 controls, was performed. We estimated risk (odds ratio and 95% confidence intervals) of endometriosis associations with the C1858T polymorphism.

Results

A significant increased risk in all genetic models of the variant T allele with endometriosis (odds ratio: 3.14-5.55; p<0.00001-0.002) was found. The analysis without the study whose controls deviated from the Hardy-Weinberg equilibrium exacerbated these effects in the homozygous and recessive models (odds ratio: 7.19-9.45; p<0.00001-0.0002). In the Italian subgroup, a significant risk association was found in the homozygous and recessive models (odds ratio: 8.72-11.12; p=0.002).

Conclusion

The associations observed between PTPN22 (C1858T) and the risk of endometriosis suggest this polymorphism might be a useful susceptibility marker for this disease.

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.

Interplay between Misplaced Müllerian-Derived Stem Cells and Peritoneal Immune Dysregulation in the Pathogenesis of Endometriosis

In the genetic regulation of Müllerian structures development, a key role is played by Hoxa and Wnt clusters, because they lead the transcription of different genes according to the different phases of the organogenesis, addressing correctly cell-to-cell interactions, allowing, finally, the physiologic morphogenesis. Accumulating evidence is suggesting that dysregulation of Wnt and/or Hox genes may affect cell migration during organogenesis and differentiation of Müllerian structures of the female reproductive tract, with possible dislocation and dissemination of primordial endometrial stem cells in ectopic regions, which have high plasticity to differentiation. We hypothesize that during postpubertal age, under the influence of different stimuli, these misplaced and quiescent ectopic endometrial cells could acquire new phenotype, biological functions, and immunogenicity. So, these kinds of cells may differentiate, specializing in epithelium, glands, and stroma to form a functional ectopic endometrial tissue. This may provoke a breakdown in the peritoneal cavity homeostasis, with the consequent processes of immune alteration, documented by peripheral mononuclear cells recruitment and secretion of inflammatory cytokines in early phases and of angiogenic and fibrogenic cytokines in the late stages of the disease.

The association of PTPN22 polymorphism with endometriosis: effect of genetic and clinical factors

OBJECTIVE

To investigate the possible effect of clinical and genetic variables on the association between PTPN22 and endometriosis.

METHODS

PTPN22, ACP₁ and p53 codon 72 genetic polymorphisms and duration of previous pharmacological treatment were studied. The study sample consisted of 132 women hospitalized for endometriosis diagnosed by laparoscopic intervention and histologically confirmed: 359 healthy blood donors were studied as controls. PTPN22, ACP1 and p53 codon 72 genotypes were determined by DNA analysis. Discriminant statistical analysis, logistic regression analysis, chi square of independence, power test and linear correlation were performed using SPSS programs.

RESULTS

A significant increase of PTPN22 *T allele in endometriosis is observed in women carrying ACP1*C allele, in women carrying p53 codon 72 *Pro allele and in women with prolonged pharmacological treatment.

CONCLUSIONS

PTPN22 may not be a primary factor in the etiology of endometriosis but may cooperate with clinical and genetic factors influencing susceptibility and clinical course of disease. These new observations point to a multifactorial origin of endometriosis and help to explain the reported differences between human populations concerning the association between PTPN22 and endometriosis.

[Neuroendocrine immunology: new pathogenetic aspects and clinical application]

After two decades of enormous improvements in anti-inflammatory therapy with biologics long-standing disease sequelae in chronic inflammatory diseases (CID) can be recognized, such as fatigue, anorexia/malnutrition, cachectic obesity, insulin resistance, dyslipidemia, changes of steroid hormone axes (e. g. loss of androgens), increased sympathetic nervous tone/decreased parasympathetic nervous tone, inflammation-related anemia and osteopenia. This article demonstrates for the first time in the German language a new theory to explain the pathophysiology of these disease sequelae. It includes concepts from evolutionary medicine and neuroendocrine regulation of energy allocation. The core statement is: the networks of energy regulation and energy allocation have been evolutionarily positively selected for transient inflammatory episodes (not for CIDs due to the negative selection pressure) but long-standing use of these adaptive programs for CID support systemic disease sequelae. These considerations might help to deviate focus from pure anti-inflammatory treatment to adequate diagnosis and therapy of systemic disease sequelae.

Evolutionary medicine and chronic inflammatory state--known and new concepts in pathophysiology

During the last 10 years, a series of exciting observations has led to a new theory of pathophysiology using insights from evolutionary biology and neuroendocrine immunology to understand the sequelae of chronic inflammatory disease. According to this theory, disease sequelae can be explained based on redirection of energy-rich fuels from storage organs to the activated immune system. These disease sequelae are highly diverse and include the following: sickness behavior, anorexia, malnutrition, muscle wasting–cachexia, cachectic obesity, insulin resistance with hyperinsulinemia, dyslipidemia, increase of adipose tissue near inflamed tissue, alterations of steroid hormone axes, elevated sympathetic tone and local sympathetic nerve fiber loss, decreased parasympathetic tone, hypertension, inflammation-related anemia, and osteopenia. Since these disease sequelae can be found in many animal models of chronic inflammatory diseases with mammals (e.g., monkeys, mice, rats, rabbits, etc.), the evolutionary time line goes back at least 70 million years. While the initial version of this theory could explain prominent sequelae of chronic inflammatory disease, it did not however address two features important in the pathogenesis of immune-mediated diseases: the time point when an acute inflammatory disease becomes chronic, and the appearance of hypertension in chronic inflammation. To address these aspects more specifically, a new version of the theory has been developed. This version defines more precisely the moment of transition from acute inflammatory disease to chronic inflammatory disease as a time in which energy stores become empty (complete energy consumption). Depending on the amount of stored energy, this time point can be calculated to be 19–43 days. Second, the revised theory addresses the mechanisms of essential hypertension since, on the basis of water loss, acute inflammatory diseases can stimulate water retention using a positively selected water retention system (identical to the energy provision system). In chronic smoldering inflammation, however, there is no increased water loss. In contrast, there is increased water generation in inflamed tissue and inflammatory cells, and the activation of the water retention system persists. This combination leads to a net increase of the systemic fluid volume, which is hypothesized to be the basis of essential hypertension (prevalence in adults 22–32%).

Polymorphism of the estrogen receptor β gene is related to infertility and infertility-associated endometriosis

OBJECTIVE

To determine the frequency of the estrogen receptor b gene (ERβ) +1730 G/A polymorphism in infertile women with and without endometriosis and controls.

SUBJECTS AND METHODS

Case-control study that included 136 women with endometriosis, 69 women without endometriosis and 209 fertile women as controls. The ERβ gene + 1730 G/A polymorphism was identified by RFLP-PCR (Restriction Fragment Length Polymorphism - Polymerase Chain Reaction).

RESULTS

Genotypes GG, GA and AA of the ERβ gene presented frequencies of 60.3%, 38.2% and 1.5%, respectively, in the women with endometriosis (p < 0.0022). Of the infertile women without endometriosis, 63.8% presented the normal homozygous genotype GG, 30.4% the GA heterozygous genotype, and 5.8% the homozygous mutated genotype AA (p < 0.0275). In the control group, 77.5% presented the normal homozygous genotype GG, 21.1% the heterozygous genotype GA, and 1.4% the homozygous mutated genotype AA.

CONCLUSION

The data suggest that the estrogen receptor β gene (ERβ) +1730 G/A polymorphism can be associated with risk of infertility and endometriosis-associated infertility.

T-cell receptor beta polymorphism is not associated with endometriosis

AIM

We carried out an association study between T-cell receptor beta polymorphism (TCRB) and endometriosis to investigate the difference in allelic frequency. Polymorphisms in T-cell receptor genes can provide important information for the study of the immune response and autoimmune diseases; indeed, rs1800907, a very common single nucleotide polymorphism (SNP) of the TCRB, has been extensively studied in autoimmune diseases in the 1990s using Southern blot analysis and more recently polymerase chain reaction (PCR) and sequencing. An autoimmune etiology for endometriosis has been strongly suggested for the presence of antibodies against endometrium, high rates of autoimmune disorders and associated atopic diseases.

MATERIAL AND METHODS

We investigated 70 patients with endometriosis and 120 controls. DNA of patients and controls was studied by PCR followed by restriction digestion and sequencing to determine genotype and presence of linkage disequilibrium (LD). Statistical analysis was carried out using STATA Routine GENHW (StataCorp, College Station, TX, USA) for estimation of Hardy-Weinberg equilibrium and test power calculation. The difference of allele distribution between patients and controls was calculated according to Pearson's and Fisher's tests. Test power for the estimation of linkage disequilibrium is low (0.16).

RESULTS

We performed an association study of the SNP rs1800907 of TCRB between 70 patients with endometriosis and 120 controls, and did not find any significant difference (χ(2) = 0.27 and P = 0.87). Fisher's test confirmed a P-value of 0.872.

CONCLUSION

Our study does not suggest an evidential and major involvement of TCRB in the pathogenesis of endometriosis in an Italian population in a small case control study.

PTPN22 1858C>T (R620W) functional polymorphism and human longevity

The PTPN22 gene, located on chromosome 1p13, encoding lymphoid protein tyrosine phosphatase (LYP), plays a crucial role in the negative control of T lymphocyte activation. Since the age-related change in T-cell signal transduction may be one of the most important causes of cell-mediated immune response decline with ageing, we performed a population-based association study to test whether the PTPN22 1858C>T (R620W) functional polymorphism affects the ability to survive to old age and to reach even exceptional life expectancy. 892 unrelated healthy individuals (age range 8-106 years, 403 males and 489 females) from central Italy were studied. For both gender, the frequency of PTPN22*T1858 carriers does not differ significantly in nona/centenarians and in octogenarians respect to young group. Allele and genotype frequencies of age groups were compared to those reported in previously published studied carried out on control individuals with Italic ancestry (N = 1393), further confirming results obtained from our sample population. Overall, our study suggests that PTPN22*T1858 allele is not negatively selected at oldest ages and we speculate that its increased ability to protect individuals against development of infectious diseases may counteract its deleterious effect on immune system leading to autoimmunity.

Luteinizing hormone beta-subunit gene (LHbeta) polymorphism in infertility and endometriosis-associated infertility

OBJECTIVE

To establish the frequency of LHbeta G1502A polymorphism in infertile women with endometriosis, infertile women without endometriosis and a control group.

STUDY DESIGN

Case-control study including 110 infertile women with endometriosis, 84 infertile women without endometriosis and a control group consisting 209 healthy fertile women recruited from the ABC School of Medicine. The LHbeta G1502A polymorphism was studied by RPLP-PCR (restriction fragment length polymorphism-polymerase chain reaction).

RESULTS

Genotypes GG, GA and AA of the LHbeta G1502A polymorphism presented frequencies of 54.6%, 31.8% and 13.6%, respectively, in the women with endometriosis (p=0.0398); of 52.4%, 38.1% and 9.5% (p=0.0123), respectively, in the infertile women without endometriosis; and of 68.9%, 21.5% and 9.6%, respectively, in the control group. In patients with minimal/mild endometriosis and moderate/severe endometriosis, the GG, GA and AA genotype frequencies were, respectively, 47.3%, 36.4% and 16.3% (p=0.0118); and 61.8%, 27.3% and 10.9% (p=0.5975). Considering the alleles, allele G was present in 70.5% of the patients with endometriosis, 71.4%% of the infertile women without endometriosis and in 79.7% of the controls, whereas allele A was present in 29.5%, 28.6% and 20.3%, respectively, in the infertile women with endometriosis (p=0.0121), infertile women without endometriosis (p=0.0409) and controls. Alleles G and A presented frequencies of 65.5% and 34.5% and 75.5% and 24.5%, respectively, in minimal/mild endometriosis (p=0.0026) and moderate/severe endometriosis (p=0.4062).

CONCLUSION

The data suggest that LHbeta G1502A polymorphism may be involved in the predisposition to infertility and minimal/mild endometriosis-associated infertility, although endometriosis might be only a coincidental finding along with infertility.

The progins progesterone receptor gene polymorphism is not related to endometriosis-associated infertility or to idiopathic infertility

OBJECTIVE

This study aimed to determine the frequency of the PROGINS polymorphism in women with endometriosis-associated infertility, in infertile women without endometriosis and in controls.

INTRODUCTION

The human progesterone receptor gene has two isoforms that modulate the biological action of progesterone: isoform A, which is capable of inhibiting the activation of the estrogen receptors, and isoform B, which has the capacity to activate the estrogen receptors. Several polymorphisms have been described for this gene, among which one stands out: a polymorphism named PROGINS, which has been speculated to be related to the genesis of endometriosis by several studies with conflicting results.

METHODS

This was a prospective study that included 148 patients with endometriosis-associated infertility, 50 idiopathic infertile patients and 179 fertile women as controls. The PROGINS polymorphism was studied by PCR.

RESULTS

Genotypes P1P1, P1P2 and P2P2 (P2 representing the PROGINS polymorphism) of the progesterone receptor gene presented frequencies of 93.9%, 5.4% and 0.7%, respectively, in the women with endometriosis-associated infertility (p=0.2101, OR=0.51, 95% CI=0.24-1.09); 94.4%, 4.2% and 1.4%, respectively, in the patients with minimal/mild endometriosis (p=0.2725, OR=0.53, 95% CI=0.20-1.43); 93.5%, 6.5% and 0%, respectively, among the patients with moderate/severe endometriosis (p=0.3679, OR=0.49, 95% CI=0.18-1.31); 86.0%, 14.0% and 0%, respectively, in idiopathic infertile women (p=0.8146, OR=1.10, 95% CI=0.46-2.63); and 88.3%, 10.6% and 1.1%, respectively, in the control group.

CONCLUSION

The data suggest that PROGINS is not related either to endometriosis-associated infertility or to idiopathic infertility in the population studied.

The search for genes contributing to endometriosis risk

BACKGROUND

Genetic variation contributes to the risk of developing endometriosis. This review summarizes gene mapping studies in endometriosis and the prospects of finding gene pathways contributing to disease using the latest genome-wide strategies.

METHODS

To identify candidate-gene association studies of endometriosis, a systematic literature search was conducted in PubMed of publications up to 1 April 2008, using the search terms 'endometriosis' plus 'allele' or 'polymorphism' or 'gene'. Papers included were those with information on both case and control selection, showed allelic and/or genotypic results for named germ-line polymorphisms and were published in the English language.

RESULTS

Genetic variants in 76 genes have been examined for association, but none shows convincing evidence of replication in multiple studies. There is evidence for genetic linkage to chromosomes 7 and 10, but the genes (or variants) in these regions contributing to disease risk have yet to be identified. Genome-wide association is a powerful method that has been successful in locating genetic variants contributing to a range of common diseases. Several groups are planning these studies in endometriosis. For this to be successful, the endometriosis research community must work together to genotype sufficient cases, using clearly defined disease classifications, and conduct the necessary replication studies in several thousands of cases and controls.

CONCLUSIONS

Genes with convincing evidence for association with endometriosis are likely to be identified in large genome-wide studies. This will provide a starting point for functional and biological studies to develop better diagnosis and treatment for this debilitating disease.