The association between chronic endometritis and uterine fibroids

GWAS-Significant Loci and Uterine Fibroids Risk: Analysis of Associations, Gene-Gene and Gene-Environmental Interactions

BACKGROUND

Uterine fibroids (UF) is the most common benign tumour of the female reproductive system. We investigated the joint contribution of genome-wide association studies (GWAS)-significant loci and environment-associated risk factors to the UF risk, along with epistatic interactions between single nucleotide polymorphisms (SNPs).

METHODS

DNA samples from 737 hospitalised patients with UF and 451 controls were genotyped using probe-based PCR for seven common GWAS SNPs: rs117245733 LINC00598, rs547025 SIRT3, rs2456181 ZNF346, rs7907606 STN1, SLK, rs58415480 SYNE1, rs7986407 FOXO1, and rs72709458 TERT.

RESULTS

We observed an association between rs547025 SIRT3 and the decreased risk of UF in overall group (effect allele C, odds ratio (OR) = 0.61, 95% confidence interval (CI) = 0.43-0.866, p = 0.005). SNP rs547025 exhibits protective effects against UF exclusively in patients with normal fruit and vegetable intake (OR = 0.39, 95% CI = 0.21-0.75, p = 0.002), no history of spontaneous abortions (OR = 0.48, 95% CI = 0.33-0.70, p = 0.0001), no pelvic inflammatory diseases (PID) in anamnesis (OR = 0.55, 95% CI = 0.38-0.80, p = 0.0016), and in smokers (OR = 0.20, 95% CI = 0.06-0.65, p = 0.006). In addition, rs7907606 STN1, SLK was associated with the risk of UF in patients without a history of pelvic inflammatory diseases (PID) (OR = 1.34, 95% CI = 1.03-1.74, p = 0.028). SNPs rs547025 SIRT3 and rs7907606 STN1, SLK, displayed the strongest mono-effects (0.71% and 0.52% contribution to UF entropy) and were characterized by the most pronounced gene-gene (G×G) effects when interacting with each other (0.60% contribution to entropy). The interaction Medical abortion×rs547025 SIRT3 served as the base for all the best gene-environment (G×E) models. Medical abortions have the most pronounced mono-effect (1.15% contribution to the entropy of UF), exceeding the mono-effects of SNPs involved in the most significant G×E-models (0.01%-0.49% contribution to entropy) and spontaneous abortions (0.48% of UF entropy) and exceeding the effects of G×E interactions (0.05-0.46% of UF entropy).

CONCLUSIONS

Bioinformatics analysis showed that GWAS SNPs are involved in the molecular mechanisms of UF mainly through the regulation of vasculogenesis, cell proliferation, apoptosis, DNA damage, inflammation, hypoxia, steroid hormone metabolism, cell signaling, organ formation.

Risk factors of chronic endometritis in women who have undergone hysteroscopy: a prospective nested case-control study

There is limited research on risk factors for chronic endometritis regarding reproductive history and clinical symptoms. Thus, this nested case-control study identified risk factors for chronic endometritis in women who have undergone hysteroscopy. Endometrial tissue sections were obtained from 502 women with intrauterine disorders who underwent hysteroscopy. Chronic endometritis was diagnosed via CD138 immunostaining. The women were divided into two groups: 271 women without chronic endometritis and 231 women with chronic endometritis. The prevalence of chronic endometritis was 46%. Univariate logistic regression revealed that prolonged menstruation and intermenstrual bleeding were associated with chronic endometritis, and subsequent multivariate logistic regression analyses showed that these were further independently associated. With univariable logistic regression, the gravidity and abortion history were correlated with chronic endometritis; however, no significant correlation was found with the adjusted odds ratio (OR) of 0.74 (95% confidence interval [CI] 0.46-1.19) or 0.76 (95% CI 0.58-1.11), respectively. No significant correlation was found between caesarean section history and the rates of chronic endometritis. No significant difference was found in all other variables between the three groups with > 5, ≤ 5 plasma cells and in a unknown group. Prolonged menstruation and intermenstrual bleeding were risk factors associated with chronic endometritis. Chronic endometritis should be considered and CD138 immunohistochemical examination should be recommended in women with these symptoms.

A comprehensive genome-wide cross-trait analysis of sexual factors and uterine leiomyoma

Age at first sexual intercourse (AFS) and lifetime number of sexual partners (NSP) may influence the pathogenesis of uterine leiomyoma (UL) through their associations with hormonal concentrations and uterine infections. Leveraging summary statistics from large-scale genome-wide association studies conducted in European ancestry for each trait (NAFS = 214,547; NNSP = 370,711; NUL = 302,979), we observed a significant negative genomic correlation for UL with AFS (rg = -0.11, P = 7.83×10-4), but not with NSP (rg = 0.01, P = 0.62). Four specific genomic regions were identified as contributing significant local genetic correlations to AFS and UL, including one genomic region further identified for NSP and UL. Partitioning SNP-heritability with cell-type-specific annotations, a close clustering of UL with both AFS and NSP was identified in immune and blood-related components. Cross-trait meta-analysis revealed 15 loci shared between AFS/NSP and UL, including 7 novel SNPs. Univariable two-sample Mendelian randomization (MR) analysis suggested no evidence for a causal association between genetically predicted AFS/NSP and risk of UL, nor vice versa. Multivariable MR adjusting for age at menarche or/and age at natural menopause revealed a significant causal effect of genetically predicted higher AFS on a lower risk of UL. Such effect attenuated to null when age at first birth was further included. Utilizing participant-level data from the UK Biobank, one-sample MR based on genetic risk scores yielded consistent null findings among both pre-menopausal and post-menopausal females. From a genetic perspective, our study demonstrates an intrinsic link underlying sexual factors (AFS and NSP) and UL, highlighting shared biological mechanisms rather than direct causal effects. Future studies are needed to elucidate the specific mechanisms involved in the shared genetic influences and their potential impact on UL development.

Racial disparity in uterine leiomyoma: new insights of genetic and environmental burden in myometrial cells

Uterine leiomyoma (LM), also known as uterine fibroids, are common gynecological tumors and can reach a prevalence of 70% among women by the age of 50 years. Notably, the LM burden is much higher in Black women with earlier onset, a greater tumor number, size, and severity compared to White women. Published knowledge shows that there are genetic, environmental, and lifestyle-based risk factors associated with racial disparity for LM. Significant strides have been made on genomic, epigenomic, and transcriptomic data levels in Black and White women to elucidate the underlying pathomolecular reasons of racial disparity in LM development. However, racial disparity of LM remains a major area of concern in gynecological research. This review highlights risk factors of LM and their role in different races. Furthermore, we discuss the genetics and uterine myometrial microenvironment in LM development. Comparative findings revealed that a major racial difference in the disease is linked to myometrial oxidative burden and altered ROS pathways which is relevant to the oxidized guanine in genomic DNA and MED12 mutations that drive the LM genesis. Considering the burden and morbidity of LM, we anticipate that this review on genetic risk and myometrial microenvironment will strengthen understanding and propel the growth of research to address the racial disparity of LM burden.

Uterine fibroids - Causes, impact, treatment, and lens to the African perspective

Leiomyomas, or uterine fibroids as they are commonly known, are mostly seen in women of reproductive age. However, they can go undetected in most women, and approximately 25% of women show clinical symptoms. Although fibroids are a global burden impacting 80% of premenopausal women, they are more prevalent among Black women than among women of other races. Based on clinical diagnosis, the estimated cumulative incidence of fibroids in women ≤50 years old is significantly higher for black (>80%) versus white women (∼70%). The cause of leiomyomas is not clearly known, but studies have shown evidence of factors that drive the development or exacerbation of the disease. Evidence has linked risk factors such as lifestyle, age, environment, family history of uterine fibroids, and vitamin D deficiencies to an increased risk of uterine fibroids, which impact women of African descent at higher rates. Treatments may be invasive, such as hysterectomy and myomectomy, or non-invasive, such as hormonal or non-hormonal therapies. These treatments are costly and tend to burden women who have the disease. Sub-Saharan Africa is known to have the largest population of black women, yet the majority of uterine fibroid studies do not include populations from the continent. Furthermore, the prevalence of the disease on the continent is not well determined. To effectively treat the disease, its drivers need to be understood, especially with regard to racial preferences. This paper aims to review the existing literature and build a case for conducting future research on African women.

Correlation Between Platelet-Lymphocyte Ratio and Neutrophil-Lymphocyte Ratio in Patients with Uterine Leiomyoma: A Cross-Sectional Study

The inflammatory reaction has been proven to be a key factor in the pathogenesis of uterine leiomyoma. The platelet-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) are inexpensive and reliable inflammatory biomarkers. However, evidence of the relationship between PLR and NLR in patients with uterine leiomyoma is limited. This study aimed to explore the relationship between PLR and NLR in patients with incident uterine leiomyoma. This cross-sectional study included 763 patients with uterine leiomyoma who were first diagnosed in our hospital between January 2016 and December 2016. Patient characteristics were collected for univariate analysis, smooth curve fitting, and multivariate piecewise linear regression. Overall, 722 patients with an average age of 40.16 ± 5.99 years were included. The average PLR was 161.22 ± 65.33. Univariate analysis revealed a significant positive correlation between PLR and NLR (P < 0.0001). In addition, the non-linear relationship between the PLR and NLR was tested using smooth curve fitting after adjusting for potential confounding factors. The multivariate piecewise linear regression model showed that there was a significant positive correlation between PLR and NLR in both PLR <226.45 (β 0.01, 95% CI: 0.01, 0.01;P < 0.0001) and >226.45 (β 0.00, 95% CI: 0.00, 0.00; P=0.0026). In conclusion, PLR and NLR are positively correlated in patients with uterine leiomyoma. This result clarifies the promoting role of inflammation in the occurrence of uterine leiomyoma.