Self-Reported Reproductive Tract Infections and Ultrasound Diagnosed Uterine Fibroids in African-American Women

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.

Uterine fibroids and longitudinal profiles of the vaginal microbiota in a cohort presenting for transvaginal ultrasound

Bacterial vaginosis, characterized in part by low levels of vaginal Lactobacillus species, has been associated with pro-inflammatory cytokines which could fuel uterine fibroid development. However, prior work on the associations between uterine fibroids and vaginal bacteria is sparse. Most studies have focused on assessment of individual taxa in a single sample. To address research gaps, we sought to compare short, longitudinal profiles of the vaginal microbiota in uterine fibroid cases versus controls with assessment for hormonal contraceptives (HCs), a possible confounder associated with both protection from fibroid development and increases in Lactobacillus-dominated vaginal microbiota. This is a secondary analysis of 83 reproductive-age cisgender women who presented for transvaginal ultrasound (TVUS) and self-collected mid-vaginal swabs daily for 1-2 weeks before TVUS (Range: 5-16 days, n = 697 samples). Sonography reports detailed uterine fibroid characteristics (N = 21 cases). Vaginal microbiota was assessed by 16S rRNA gene amplicon sequencing and longitudinal microbiota profiles were categorized by hierarchical clustering. We compared longitudinal profiles of the vaginal microbiota among fibroid cases and controls with exact logistic regression. Common indications for TVUS included pelvic mass (34%) and pelvic pain (39%). Fibroid cases tended to be older and report Black race. Cases less often reported HCs versus controls (32% vs. 58%). A larger proportion of cases had low-Lactobacillus longitudinal profiles (48%) than controls (34%). In unadjusted analysis, L. iners-dominated and low-Lactobacillus profiles had higher odds of fibroid case status compared to other Lactobacillus-dominated profiles, however these results were not statistically significant. No association between vaginal microbiota and fibroids was observed after adjusting for race, HC and menstruation. Results were consistent when number of fibroids were considered. There was not a statistically significant association between longitudinal profiles of vaginal microbiota and uterine fibroids after adjustment for common confounders; however, the study was limited by small sample size.

Dysbiosis of vaginal and cervical microbiome is associated with uterine fibroids

Dysbiosis of the female reproductive tract is closely associated with gynecologic diseases. Here, we aim to explore the association between dysbiosis in the genital tract and uterine fibroids (UFs) to further provide new insights into UF etiology. We present an observational study to profile vaginal and cervical microbiome from 29 women with UFs and 38 healthy women, and 125 samples were obtained and sequenced. By comparing the microbial profiles between different parts of the reproductive tract, there is no significant difference in microbial diversity between healthy subjects and UF patients. However, alpha diversity of UF patients was negatively correlated with the number of fibroids. Increased Firmicutes were observed in both the cervical and vaginal microbiome of UF patients at the phylum level. In differential analysis of relative abundance, some genera were shown to be significantly enriched (e.g., Erysipelatoclostridium, Mucispirillum, and Finegoldia) and depleted (e.g., Erysipelotrichaceae UCG-003 and Sporolactobacillus) in UF patients. Furthermore, the microbial co-occurrence networks of UF patients showed lower connectivity and complexity, suggesting reduced interactions and stability of the cervical and vaginal microbiota in UF patients. In summary, our findings revealed the perturbation of microbiome in the presence of UFs and a distinct pattern of characteristic vaginal and cervical microbiome involved in UFs, offering new options to further improve prevention and management strategies.

Intravascular leiomyomatosis: a continuing diagnostic challenge

We report the case of a woman in her 60s with intravascular leiomyomatosis. She suffered from numerous non-specific symptoms including weight loss, anaemia and sudden swelling of the left lower extremity. CT imaging showed the presence of an enlarged left ovary and a thrombus extending from the left ovarian venous plexus intruding into the right atrium of the heart. Cancer antigen 125 was 20 U/mL. Pelvic transvaginal ultrasound examination identified two normal ovaries and a mass adjacent to the left ovary. A second opinion on the CT scan was requested at a oncogynaecological multidisciplinary team meeting, where the radiologist of the team identified an intervascular leiomyomatosis. After further investigation, surgical treatment was planned and completed in collaboration with the departments of cardiothoracic and vascular surgery. The patient recovered fully.

Epidemiology of uterine fibroid in black African women: a systematic scoping review

OBJECTIVE

Studies, mainly from high-income countries, suggest that there are ethnic and racial variations in prevalence of uterine fibroids (UF). However, there have been few studies of the epidemiology of UF in sub-Saharan Africa (SSA). We reviewed published articles on the epidemiology of UF in SSA.

DESIGN

This was a scoping review of literature.

SETTINGS

We searched three databases (PubMed, African Wide Information (EBSCO) and African Journals OnLine (AJOL)). The search for eligible articles was conducted between December 2019 and January 2021.

PRIMARY AND SECONDARY OUTCOME MEASURES

To describe the reported prevalence/incidence of, and risk factors for UF in SSA.

RESULTS

Of the 1052 articles retrieved, 9 met the inclusion criteria for review. The articles were from Nigeria (4/9), Ghana (2/9), Cameroon (1/9), Kenya (1/9) and South Africa (1/9). Two studies from pathology departments and three studies from radiology departments reported prevalence of UF. We did not find any study on the incidence or genomics of UF in SSA. Of the three studies that reported on the risk factors of UF, only one case-control study that was conducted using retrospective data of attendees at a gynaecological clinic conducted multivariable analysis.

CONCLUSION

There is lack of robust epidemiological studies of the prevalence, incidence and risk factors of UF in SSA. There is urgent need to study epidemiological and genomics risk factors of UF in SSA because UF is the most common gynaecological neoplasm in this population where it is associated with significant morbidity and occasional, usually perioperative, mortality.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

Bacterial Vaginosis and Prospective Ultrasound Measures of Uterine Fibroid Incidence and Growth

BACKGROUND

Uterine fibroids often cause intolerable symptoms leading to invasive treatments, most commonly hysterectomy. Reproductive tract infections are hypothesized to influence uterine fibroid development, but few studies exist, especially for the highly prevalent condition bacterial vaginosis (BV). Both fibroids and BV have documented racial-ethnic disparities, with higher burden in Blacks.

METHODS

With prospective data from a community-based study (four standardized ultrasound examinations over 5 years) in young Black women, we examined baseline BV associations with fibroid incidence and growth. We computed adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incidence comparing BV and no BV (Nugent score ≥7 vs. <7) using Cox proportional hazards models among 1027 women fibroid-free at baseline. Fibroid growth associations were based on linear mixed models estimating volume change between ultrasounds indexed to 18 months. We then expressed BV association as estimated percent difference in growth per 18 months, comparing exposed and unexposed.

RESULTS

There were n = 247 incident fibroids and 1181 growth measures; average fibroid growth per 18 months was a 78% (95% CI: 69 to 87) increase in volume. BV prevalence was 51% and not associated with fibroid incidence (aHR: 1.0, 95% CI: 0.80 to 1.4) or growth (estimated % difference in growth, -3% (95% CI: -12 to 6).

CONCLUSIONS

In this first study (to our knowledge) of ultrasound-monitored fibroid development and Nugent-assessed BV, we found no evidence to support the hypothesis that BV increased risk of fibroid incidence or growth or BV's role in the high burden of fibroids in Black women.

Genital Chlamydia trachomatis Seroprevalence and Uterine Fibroid Development: Cohort Study of Young African-American Women

Few studies have investigated the 1930s hypothesis that reproductive tract infections are risk factors for fibroid development. In our 2017 cross-sectional analysis from the Study of Environment, Lifestyle, and Fibroids (2010–2018), a large Detroit community-based cohort of 23–35 year-old African-American women with ultrasound fibroid screening, we found an inverse association between seropositivity for genital Chlamydia trachomatis (gCT) infection and fibroids. With prospective data from the cohort (standardized ultrasounds every 20 months over 5 years), we examined gCT’s associations with fibroid incidence (among 1158 women fibroid-free at baseline) and growth. We computed adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incidence by gCT serostatus using Cox proportional hazards models. GCT’s influence on growth was assessed by estimating the difference between fibroid size change for seropositive vs. seronegative between successive ultrasounds (1254 growth measures) using a linear mixed model. Growth was scaled to change over 18 months. GCT seropositivity was not associated with fibroid incidence (aHR, 1.0 95% CI: 0.79, 1.29) or growth (4.4%, 95% CI: −5.02, 14.64). The current evidence based on both biomarker gCT data, which can capture the common undiagnosed infections, and prospective ultrasound data for fibroids suggests that Chlamydia is unlikely to increase fibroid risk.

Douching or Perineal Talc Use and Prevalent Fibroids in Young African American Women

Background: Black women are at an increased risk of developing fibroids, but the cause is unclear. Douching and perineal talc use are common lifestyle exposures among Black women, and may be risk factors for fibroid development. Materials and Methods: This cross-sectional study consisted of Black women 23-35 years of age in the metropolitan Detroit area (n = 1693) without prior diagnoses of fibroids and intact uteri. Main exposures were ever douching (yes/no) and any perineal talc use (ever/never). Main outcomes were prevalent fibroids at baseline (yes/no) and total fibroid volume at baseline (no fibroids/ Collapse

Key Words

• Women's Health
• douching
• health disparities
• talc
• uterine leiomyoma

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MESH Headings

• Black or African American
• Cross-Sectional Studies
• Female
• Humans
• Leiomyoma/epidemiology
• Prospective Studies
• Talc/adverse effects
• Therapeutic Irrigation
• Uterine Neoplasms

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Grants

• R00 NR017191 NINR NIH HHS

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Affiliation(s)

Maya A. Wright Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, North Carolina, USA
Kristen R. Moore Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
Kristen Upson Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, Michigan, USA
Donna D. Baird Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
Helen B. Chin Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA

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Bacterial Vaginosis-Associated Bacteria and Uterine Fibroids: A Nested Case-Control Study

BACKGROUND

Reproductive tract infections are hypothesized to influence uterine fibroid development, yet few studies have investigated the common condition of bacterial vaginosis (BV). The literature is currently limited to data using self-report of BV.

METHODS

We conducted a nested case-control study of 200 women (100 cases and 100 controls) from a large study of 23- to 35-year-old African American women, 1310 of whom were fibroid-free and prospectively followed up for 5 years to identify incident fibroids with standardized ultrasound examinations. We used quantitative polymerase chain reaction, an objective molecular method, to assess 9 BV-associated and 4 Lactobacillus species from vaginal swab specimens. We used hierarchical logistic regression to compute odds ratios and 95% confidence intervals to examine associations between bacterial species (both individually and grouped as (1) "optimal" Lactobacillus and (2) BV-associated species) with fibroid incidence and number. We also examined vaginal imbalance (quantitatively more BV-associated bacteria than optimal Lactobacilli).

RESULTS

Contrary to our hypothesis, we found no increase in fibroid incidence or number among women with more BV-associated bacteria. High imbalance (only BV-associated bacteria, no optimal Lactobacillus bacteria) was actually inversely associated with fibroid incidence (odds ratio, 0.38; 95% confidence interval, 0.17-0.81).

CONCLUSIONS

This is the first study of ultrasound-detected incident fibroids and molecular vaginal bacterial assessment. We found no evidence that BV-associated bacteria increase the risk of fibroid incidence or number.

Herpes Simplex Virus Type 2 Seroprevalence and Incidence and Growth of Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women

Reproductive tract infections have long been hypothesized to be risk factors for development of uterine fibroids, but few studies have investigated the issue. In our 2016 cross-sectional analysis from the Study of Environment, Lifestyle and Fibroids (2010-2018), a large Detroit, Michigan, community-based cohort study of 23- to 35-year-old African-American women with ultrasound fibroid screening, we found no association between a very prevalent reproductive tract infection, herpes simplex virus type 2 (HSV-2), and fibroids. With prospective data from the cohort (ultrasounds performed every 20 months over 5 years), we examined HSV-2's associations with fibroid incidence (among 1,208 women who were fibroid-free at baseline) and growth (among women with fibroids at baseline or diagnosed during the study). Using Cox proportional hazards models, we computed adjusted hazard ratios and 95% confidence intervals for fibroid incidence comparing HSV-2-seropositive women with HSV-2-seronegative women. The influence of HSV-2 infection on growth was assessed on the basis of the difference in fibroid size between successive ultrasounds (1,323 growth measures) using a linear mixed model, estimating the percent difference in growth scaled to 18 months. HSV-2 seropositivity was not associated with fibroid incidence (adjusted hazard ratio = 0.88, 95% confidence interval: 0.69, 1.12) or growth (estimated growth difference = 3.1%, 95% confidence interval: -5.8, 13.0). Women can be reassured that HSV-2 infection is unlikely to increase their risk of fibroid-related health problems, given these longitudinal measures.

Uterine Leiomyoma and Reproductive Tract Infections Detected by Polymerase Chain Reaction

Background and Objective:

For nearly a century, it has been suspected that reproductive tract infections play an etio- logic role in uterine leiomyoma. However, no epidemiologic study of leiomyoma has used the polymerase chain reaction (PCR) to compare uterine tissues from cases and non-cases, and to investigate associations between uterine leiomyoma and infections detected by PCR.

Methods:

In this case-control study, 92 leiomyoma tissues from cases, and 94 myometrial tissue from controls were screened by PCR for cytomegalovirus, Chlamydia trachomatis, herpes simplex virus-1, 2, and human papillomavirus typed as 16/18 or another strain. Multivariable analysis used age-adjusted logistic regression, and generalized linear regression as appropriate.

Results:

In the uterine tissues of cases and unmatched controls, the prevalence of infection was: cytomegalovirus (32.6%, 7.4%), C. trachomatis (23.9%, 37.2%), herpes simplex virus-1,2 (25.0%, 13.8%), human papillomavirus 16/18 (13.0%, 10.5%). Leiomyoma was associated with cytomegalovirus (Odds Ratio (O.R.) 6.10; 95% confidence interval (C.I.), 2.40, 15.55) and Chlamydia (O.R. 0.47; 95% C.I. 0.23, 0.97). Likewise, the log count of leiomyoma was higher

with cytomegalovirus (+0.65, 95% C.I. +0.34, +0.95) and lower with Chlamydia (-0.71, 95% C.I. -1.12, -0.29).

Conclusion:

This first application of PCR to leiomyomata and control uterine tissues from non-cases reveals that cytomegalovirus is associated with the presence, number, and volume of uterine leiomyoma, while C. trachomatis is inversely associated with leiomyoma, but only in the absence of cytomegalovirus. Current findings provide preliminary evidence that common reproductive tract infections contribute to the growth and control of at least some cases of uterine leiomyoma.

Factors targeting MED12 to drive tumorigenesis?

Mediator Complex Subunit 12 (MED12) is part of the transcriptional preinitiation machinery. Mutations of its gene predominantly occur in two types of highly frequent benign tumors, uterine leiomyomas and fibroadenomas of the breast, where they apparently act as driver mutations. Nevertheless, their presence is not restricted to benign tumors having been found at considerable frequencies in uterine leiomyosarcomas, malignant phyllodes tumors, and chronic lymphocytic leukemia also. Most of the mutations are located within exon 2 of the gene but in rare cases the intron 1/exon 2 boundary or exon 1 are affected. As to their type, predominantly single nucleotide exchanges with a hotspot in one codon are found, but small deletions clustering around that hotspot also are not uncommon. These latter deletions are leaving the open reading frame intact. As to the types of mutations, so far no apparent differences between the tumor entities affected have emerged. Interestingly, this pattern with small deletions clustered around the hotspot of single nucleotide exchanges resembles that seen as a result of targeted gene editing. In contrast to other driver mutations the percentage of MED12-mutation positive tumors of independent clonal origin increases with the number of tumors per patient suggesting unknown etiological factors supporting site specific mutagenesis.  These factors may act by inducing simultaneous site-specific double strand breaks the erroneous repair of which may lead to corresponding mutations. As inducers of DNA damage and its repair such as foreign nucleic acids of the microbiome displaying sequence homology to the putative target site might play a role. Interestingly, a 16 base pair homology of the hotspot to a putative terminator base-paired hairpin sequence of a Staphylococcus aureus tRNA gene cluster has been noted which might form R-loop like structures with its target sequence thus inducing said changes.

Chlamydia trachomatis Seroprevalence and Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women

Reproductive tract infections have long been hypothesized to increase the risk of uterine fibroids. Few studies have been conducted, even for the common infection genital Chlamydia trachomatis (gCT), and only with self-reported gCT data. Our investigation used micro-immunofluorescence serology for gCT to characterize past exposure. We used cross-sectional enrollment data from a prospective fibroid study carried out in the Detroit, Michigan, area; ultrasound examinations systematically screened for fibroids. Participants were African-American women aged 23-34 years (recruited in 2010-2012). Age- and multivariable-adjusted logistic regression models were used to estimate odds ratios. A total of 1,587 women (94% of participants) had unequivocal gCT serology results; 22% had fibroids. Those who were seropositive for gCT were less likely to have fibroids (age-adjusted odds ratio = 0.68, 95% confidence interval: 0.54, 0.87; multivariable-adjusted odds ratio = 0.80, 95% confidence interval: 0.62, 1.03). Inverse associations were similar across categories of fibroid size, number, and total volume. Participant groups likely to have had multiple or severe infections (multiple serovar groups, more sex partners, clinically diagnosed chlamydia) all showed statistically significantly reduced odds of fibroids. A protective association of gCT with fibroids was unexpected but plausible. gCT infection might increase immune surveillance and eliminate early lesions. Further investigation on the relationship between fibroid development and reproductive tract infections is needed.

Multiple clinical characteristics separate MED12-mutation-positive and -negative uterine leiomyomas

Up to 86% of uterine leiomyomas harbour somatic mutations in mediator complex subunit 12 (MED12). These mutations have been associated with conventional histology, smaller tumour size, and larger number of tumours within the uterus. Prior studies, with limited sample sizes, have failed to detect associations between other clinical features and MED12 mutations. Here, we prospectively collected 763 uterine leiomyomas and the corresponding normal myometrial tissue from 244 hysterectomy patients, recorded tumour characteristics, collected clinical data from medical records, and screened the tissue samples for MED12 mutations to assess potential associations between clinical variables and mutation status. Out of 763 leiomyomas, 599 (79%) harboured a MED12 mutation. In the analysis of tumour characteristics, positive MED12-mutation status was significantly associated with smaller tumour size, conventional histology, and subserous location, relative to intramural. In the analysis of clinical variables, the number of MED12-mutation-positive tumours showed an inverse association with parity, and the number of mutation-negative tumours showed a positive association with a history of pelvic inflammatory disease. This study confirmed the previously reported differences and discovered novel differentiating features for MED12-mutation-positive and -negative leiomyomas. These findings emphasise the relevance of specific driver mutations in genesis and presentation of uterine leiomyomas.

Alcohol, cigarette smoking, and ovarian reserve in reproductive-age African-American women

BACKGROUND

Although alcohol consumption and cigarette smoking are common behaviors in reproductive-age women, little is known about the impact of consumption patterns on ovarian reserve. Even less is known about the effects of smoking and alcohol use in reproductive-age African-American women.

OBJECTIVE

The objective of the study was to examine the impact of the patterns of alcohol intake and cigarette smoking on anti-Müllerian hormone levels as a marker of ovarian reserve in African-American women.

STUDY DESIGN

This was a cross-sectional analysis from the baseline clinical visit and data collection of the Study of Environment, Lifestyle, and Fibroids performed by the National Institute of Environmental Health Sciences. A total of 1654 volunteers, aged 23-34 years, recruited from the Detroit, Michigan community completed questionnaires on alcohol intake and cigarette smoking and provided serum for anti-Müllerian hormone measurement. Multivariable linear and logistic regressions were used as appropriate to estimate the effect of a range of exposure patterns on anti-Müllerian hormone levels while adjusting for potential confounders including age, body mass index, and hormonal contraception.

RESULTS

Most participants were alcohol drinkers (74%). Of those, the majority (74%) engaged in binge drinking at least once in the last year. Women who reported binge drinking twice weekly or more had 26% lower anti-Müllerian hormone levels compared with current drinkers who never binged (95% confidence interval, -44, -2, P < .04). Other alcohol consumption patterns (both past and current) were unrelated to anti-Müllerian hormone. The minority of participants currently (19%) or formerly (7%) smoked, and only 4% of current smokers used a pack a day or more. Neither smoking status nor second-hand smoke exposure in utero, childhood, or adulthood was associated with anti-Müllerian hormone levels.

CONCLUSION

Results suggest that current, frequent binge drinking may have an adverse impact on ovarian reserve. Other drinking and smoking exposures were not associated with anti-Müllerian hormone in this cohort of healthy, young, African-American women. A longitudinal study of how these common lifestyle behaviors have an impact on the variability in age-adjusted anti-Müllerian hormone levels is merited.

Epidemiology of Uterine Fibroids: From Menarche to Menopause

Uterine leiomyomata (UL) have a substantial impact on women's health, but relatively few studies have identified opportunities for primary prevention of these neoplasms. Most established risk factors are not modifiable, including premenopausal age, African ancestry, age at menarche, and childbearing history. The main challenge in studying UL is that a large proportion of tumors are asymptomatic. Herein, we review the epidemiology of UL from published studies to date. We highlight the advantages of ultrasound screening studies and the ways in which their innovative methods have helped clarify the etiology of disease. We conclude with a discussion of promising new hypotheses.

Herpes Simplex Virus Type 2 Seroprevalence and Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women

For decades reproductive tract infections (RTIs) have been hypothesized to play a role in uterine fibroid development. The few previous studies conducted used self-reported history of RTIs and had inconsistent findings. We investigated this hypothesis further using serological analysis, an immunological measure of past exposure. We focused on herpes simplex virus type 2 (HSV-2) because prior published data have suggested a possible association with fibroids, and serology for HSV-2 is much more sensitive than self-report. We used cross-sectional enrollment data from African-American women enrolled in a prospective study of fibroid incidence and growth (recruited 2010-2012) in the Detroit, Michigan, area. The women were aged 23-34 years and were screened for fibroids using a standardized ultrasound examination at their enrollment. Age- and multivariable-adjusted logistic regression models were used to estimate odds ratios. Of 1,696 participants, 1,658 had blood samples and HSV-2 serology results; 22% of participants with serology results had fibroids. There was no significant association between HSV-2 seropositivity and the presence of fibroids (multivariable-adjusted odds ratio = 0.94, 95% confidence interval: 0.73, 1.20), nor were there any associations with size of the largest fibroid, number of fibroids, or total fibroid volume. Our data provide no evidence for an influence of HSV-2 exposure on fibroid risk in young African-American women. Further study of other serologically measured RTIs is warranted.