The association between endometriosis and autoimmune diseases: a systematic review and meta-analysis

Infertility in women with systemic autoimmune diseases

Infertility consists by definition in" failure to achieve a clinical pregnancy after 12 months or more of regular unprotected intercourse" while the term subfertility means a delay to achieve pregnancy. Several factors can contribute to infertility or subfertility in patients with systemic autoimmune diseases. The association of systemic autoimmune conditions with endometriosis, celiac disease and thyroid autoimmunity that are well known causes of infertility and/or subfertility need to be taken in consideration when difficulties in the onset of pregnancy is reported. The majority of the used antirheumatic drugs do not interfere with fertility. However, the use of cyclophosphamide, limited to severe disease, can provoke premature ovarian failure; to preserve fertility a preventive treatment is available. Nonsteroidal anti-inflammatory drugs can cause temporary infertility and corticosteroids are associated to a prolonged time to pregnancy in some rheumatic diseases. Data on the association of antiphospholipid antibodies (aPL) with infertility are still debated but in general an increased rate of aPL is described patients undergoing medically assisted reproductive techniques. In systemic lupus erythematosus aPL and other autoantibodies (i.e. anti-oocytes) can contribute to the infertility of some patients. Subfertility, rather than infertility, is observed in patients with rheumatoid arthritis; the particular physical conditions of these women can also account for this. Physicians should not forget the patients' age, that is mandatory in order to preserve their chance to have children.

Cross-disorder analysis of endometriosis and its comorbid diseases reveals shared genes and molecular pathways and proposes putative biomarkers of endometriosis

RESEARCH QUESTION

Women with endometriosis are considered to be at higher risk of several chronic diseases, such as autoimmune disorders, gynaecological cancers, asthma/atopic diseases and cardiovascular and inflammatory bowel diseases. Could the study of endometriosis-associated comorbidities help to identify potential biomarkers and target pathways of endometriosis?

DESIGN

A systematic review was performed to identify all possible endometriosis-associated comorbid conditions. Next, this list of disorders was coded into MeSH terms, and the gene expression profiles were downloaded from the Phenopedia database and subsequently analysed following a systems biology approach.

RESULTS

The results identified a group of 127 candidate genes that were recurrently expressed in endometriosis and its closest comorbidities and that were defined as 'endometriosis sibling disorders' (ESD). The enrichment analysis showed that these candidate genes are principally involved in immune and drug responses, hormone metabolism and cell proliferation, which are well-known hallmarks of endometriosis. The expression of ESD genes was then validated on independent sample cohorts (n = 207 samples), in which the involvement of 16 genes (AGTR1, BDNF, C3, CCL2, CD40, CYP17A1, ESR1, IGF1, IGF2, IL10, MMP1, MMP7, MMP9, PGR, SERPINE1 and TIMP2) in endometriosis was confirmed. Several of these genes harbour polymorphisms that associate to either endometriosis or its comorbid conditions.

CONCLUSIONS

The study results highlight the molecular processes underlying the aetiopathogenesis of endometriosis and its comorbid conditions, and identify putative endometriosis biomarkers.

Is Scientific Medical Literature Related to Endometriosis Treatment Evidence-Based? A Systematic Review on Methodological Quality of Randomized Clinical Trials

Background and objectives: Informed decision-making requires the ability to identify and integrate high-quality scientific evidence in daily practice. We aimed to assess whether randomized controlled trials (RCTs) on endometriosis therapy follow methodological criteria corresponding to the RCTs' specific level in the hierarchy of evidence in such details to allow the reproduction and replication of the study. Materials and Methods: Using the keywords "therapy" and "endometriosis" and "efficacy" three bibliographic databases were searched for English written scientific articles published from 1 January 2008 to 3 March 2018. Only the randomized clinical trials (RCTs) were evaluated in terms of whether they provided the appropriate level of scientific evidence, equivalent to level 1, degree 1b in the hierarchy of evidence. A list of criteria to ensure study replication and reproduction, considering CONSORT guideline and MECIR standards, was developed and used to evaluate RCTs' methodological soundness, and scores were granted. Three types of bias, namely selection bias (random sequence generation and allocation concealment), detection bias (blinding of outcome assessment), and attrition bias (incomplete outcome data) were also evaluated. Results: We found 387 articles on endometriosis therapy, of which 38 were RCTs: 30 double-blinded RCTs and 8 open-label RCTs. No article achieved the maximum score according to the evaluated methodological criteria. Even though 73.3% of the double-blinded RCTs had clear title, abstract, introduction, and objectives, only 13.3% provided precise information regarding experimental design and randomization, and also showed a low risk of bias. The blinding method was poorly reported in 43.3% of the double-blinded RCTs, while allocation concealment and random sequence generation were inadequate in 33.3% of them. Conclusions: None of the evaluated RCTs met all the methodological criteria, none had only a low risk of bias and provided sufficient details on methods and randomization to allow for the reproduction and replication of the study. Consequently, the appropriate level of scientific evidence (level 1, degree 1b) could not be granted. On endometriosis therapy, this study evaluated the quality of reporting in RCTs and not the quality of how the studies were performed.