Factors Associated with Participation and Attrition in a Longitudinal Study of Bacterial Vaginosis in Australian Women Who Have Sex with Women

Objective

A number of social and sexual risk factors for bacterial vaginosis (BV) have been described. It is important to understand whether these factors are associated with non-participation or attrition of participants from longitudinal studies in order to examine potential for recruitment or attrition bias. We describe factors associated with participation and attrition in a 24-month prospective cohort study, investigating incident BV among Australian women who have sex with women.

Study Design and Setting

Participants negative for prevalent BV were offered enrolment in a longitudinal cohort study. Participants self-collected vaginal samples and completed questionnaires 3-monthly to endpoint (BV-positive/BV-negative by 24 months). Factors associated with participation in the cohort study were examined by logistic regression and factors associated with attrition from the cohort were examined by Cox regression.

Results

The cross-sectional study recruited 457 women. 334 BV-negative women were eligible for the cohort and 298 (89%, 95%CI 85, 92) enrolled. Lower educational levels (aOR 2.72, 95%CI 1.09, 6.83), smoking (aOR 2.44, 95%CI 1.13, 5.27), past BV symptoms (aOR 3.42, 95%CI 1.16, 10.10) and prior genital warts (aOR 2.71, 95%CI 1.14, 6.46) were associated with non-participation; a partner co-enrolling increased participation (aOR 3.73, 95%CI 1.43, 9.70). 248 participants (83%, 95%CI 78, 87) were retained to study endpoint (BV-negative at 24 months or BV-positive at any stage). Attrition was associated being <30 yrs (aHR 2.15, 95%CI 1.13, 4.10) and a male partner at enrolment (aHR 6.12, 95%CI 1.99, 18.82).

Conclusion

We achieved high participation and retention levels in a prospective cohort study and report factors influencing participation and retention of participants over a 24-month study period, which will assist in the design and implementation of future cohort studies in sexual health and disease.     

Factors Associated with Bacterial Vaginosis among Women Who Have Sex with Women: A Systematic Review

Background

Women who have sex with women (WSW) have a higher burden of bacterial vaginosis (BV) than heterosexual women; studies of risk factors specific to this population are limited. We summarised current knowledge regarding risk factors for BV among WSW by systematic review.

Methods

This systematic review was conducted according to the PRISMA statement. PUBMED, EMBASE, Web of Science and The Cochrane Library were searched to 31^st December, 2014. Inclusion criteria: 1) WSW included in the study population; 2) accepted BV diagnostic method; 3) investigated or could extrapolate factors(s) associated with BV acquisition, persistence or transmission in WSW specifically by comparing BV positive to BV negative women. Search was limited to English-language publications.

Results

A limited number of studies have investigated BV in WSW. Of 71 unique references, 18 full-text articles were assessed and 14 studies fulfilled inclusion criteria. BV was positively associated with higher numbers of female partners, both lifetime and in the three months prior to diagnosis, and confirmed BV in a female partner, but inconsistently associated with partners’ BV history or symptoms. BV was not associated with ethnicity, vaginal douching or hormonal contraception. The impact of specific sexual activities, male sexual contact, smoking and the menstrual cycle varied considerably between study populations.

Conclusion

BV in WSW is associated with increased numbers of recent and past female partners and confirmed BV in a female partner. There are limited studies of BV in WSW populations, and research is needed to further elucidate risk factors for BV among WSW. However these data provide epidemiological evidence that BV risk in women is directly related to exposure to other female partners and a partner with BV, providing support for the concept that BV is likely to be transmitted between women.

Systematic Review Registration Number

CRD42014009536 (PROSPERO)     

Qualitative Inquiry into Premarital Sexual Behaviours and Contraceptive Use among Multiethnic Young Women: Implications for Education and Future Research

Background

This study was a qualitative investigation into sexual attitudes and behaviours, and contraceptive use among Malaysian youth, based on constructs from the health belief model, theory of reasoned action, and problem behaviour theory.

Methods

A total of 34 focus group discussions with 185 participants were conducted among the Malay (35%), Chinese (34%), and Indian (31%) young females between November, 2010 and April, 2011. The participants were secondary school students and university undergraduates from Selangor and the Federal Territory of Kuala Lumpur.

Results

The study found a lack of knowledge about sexual issues and contraception among the participants. Many engaged in unprotected sexual intercourse and relied on periodic abstinence, natural methods, and traditional folk pregnancy preventive practices. The findings also revealed numerous categories of factors influencing sexual attitudes and behaviours: ethnic group and religion, level of religiosity, peer pressure and norms, and parental monitoring. With regard to condom use, factors such as embarrassment about condom acquisition, low perceived susceptibility to sexually transmitted infections (STIs), and perceived efficacy of traditional and folk methods of contraception, were uncovered from the discussions.

Conclusion

This study underscores the importance of development of culturally specific interventions that address the identified promoting factors of premarital sex. Behavioral interventions to promote condom use should increase awareness about condom effectiveness against not only unwanted pregnancies but also STIs.     

Characterization of the Vaginal Microbiota among Sexual Risk Behavior Groups of Women with Bacterial Vaginosis

Background

The pathogenesis of bacterial vaginosis (BV) remains elusive. BV may be more common among women who have sex with women (WSW). The objective of this study was to use 454 pyrosequencing to investigate the vaginal microbiome of WSW, women who have sex with women and men (WSWM), and women who have sex with men (WSM) with BV to determine if there are differences in organism composition between groups that may inform new hypotheses regarding the pathogenesis of BV.

Methods

Vaginal swab specimens from eligible women with BV at the Mississippi State Department of Health STD Clinic were used. After DNA extraction, 454 pyrosequencing of PCR-amplified 16S rRNA gene sequences was performed. Sequence data was classified using the Ribosomal Database Program classifer. Complete linkage clustering analysis was performed to compare bacterial community composition among samples. Differences in operational taxonomic units with an abundance of ≥2% between risk behavior groups were determined. Alpha and beta diversity were measured using Shannon’s Index implemented in QIIME and Unifrac analysis, respectively.

Results

33 WSW, 35 WSWM, and 44 WSM were included. The vaginal bacterial communities of all women clustered into four taxonomic groups with the dominant taxonomic group in each being Lactobacillus, Lachnospiraceae, Prevotella, and Sneathia. Regarding differences in organism composition between risk behavior groups, the abundance of Atopobium (relative ratio (RR)=0.24; 95%CI 0.11-0.54) and Parvimonas (RR=0.33; 95%CI 0.11-0.93) were significantly lower in WSW than WSM, the abundance of Prevotella was significantly higher in WSW than WSWM (RR=1.77; 95%CI 1.10-2.86), and the abundance of Atopobium (RR=0.41; 95%CI 0.18-0.88) was significantly lower in WSWM than WSM. Overall, WSM had the highest diversity of bacterial taxa.

Conclusion

The microbiology of BV among women in different risk behavior groups is heterogeneous. WSM in this study had the highest diversity of bacterial taxa. Additional studies are needed to better understand these differences.     

Prevalence of Bacterial Vaginosis in Women Attending Family Planning Clinics

Prevalence of bacterial vaginosis in 242 women attending family planning clinics in Concepción, Chile was studied using the Nugent criteria. The syndrome was present in 33.1% of women. No statistical difference was found between the occurrence of bacterial vaginosis and the of oral contraceptives (31.9%) or intrauterine devices (33.1%). The sensitivity and specificity of the Nugent criteria compared with the Amsel criteria were 86.7% and 91.0%, respectively. Vaginal fluid pH and appearance had low specificity in this population. Microorganisms associated with bacterial vaginosis were Gardnerella vaginalis (96.3%), Prevotella/Porphyromonas (70%),Mobiluncus spp. (48.8%), Mycoplasma hominis (21.3%) and Ureaplasma urelyticum 21.3). These results suggest that preventive actions and management of clinical infection to prevent complications are needed.     

Associations between Vaginal Pathogenic Community and Bacterial Vaginosis in Chinese Reproductive-Age Women

Background

Bacterial vaginosis (BV) is one of the most common urogenital infections among women of reproductive age that represents shifts in microbiota from Lactobacillus spp. to diverse anaerobes. The aim of our study was to evalute the diagnostic values of Gardnerella, Atopobium, Eggerthella, Megasphaera typeI, Leptotrichia/Sneathia and Prevotella, defined as a vaginal pathogenic community for BV and their associations with vaginal pH and Nugent scores.

Methods and Findings

We investigated the vaginal pathogenic bacteria and Lactobacillus spp. with species-specific real-time quantitative PCR (qPCR) in 50 BV-positive and 50 BV-negative Chinese women of reproductive age. Relative to BV-negative subjects, a siginificant decline in Lactobacillus and an obvious increase in bacteria in the vaginal pathogenic community were observed in BV-postive subjects (P<0.05). With the exception of Megasphaera typeI, other vaginal pathogenic bacteria were highly predictable for BV with a better sensitivity and specificity. The vaginal pathogenic community was positively associated with vaginal pH and Nugent scores, while Lactobacillus spp., such as L. iners and L. crispatus was negatively associated with them (P<0.05).

Conclusions

Our data implied that the prevalance of vaginal pathogenic bacteria as well as the depletion of Lactobacillus was highly accurate for BV diagnosis. Vaginal microbiota shifts, especially the overgrowth of the vaginal pathogenic community, showed well diagnostic values in predicting BV. Postive correlations between those vaginal pathogenic bacteria and vaginal pH, Nugent score indicated the vaginal pathogenic community rather than a single vaginal microorganism, was participated in the onset of BV directly.     

健康妇女及3例细菌性阴道病患者阴道菌群的非培养分析

根据Amsel标准及Nugent标准, 确诊筛选健康妇女及细菌性阴道病(bacterial vaginosis, BV)患者各3例。提取其阴道分泌物样本的总DNA, 构建16S rRNA基因克隆文库, 并对阳性克隆进行ARDRA和测序分析。结果表明, 健康妇女样本的基因文库中, 分别以卷曲乳酸杆菌(L. crispatus)和惰性乳酸杆菌(L. iners)的克隆子占较大比例, 另外存在少量的阴道乳酸杆菌(L. vaginalis)或詹氏乳酸杆菌(L. jensenii)的克隆子。BV患者样本的基因文库中, 克隆子所代表的菌种类型明显增多, 但均以阴道加德纳氏菌(Gardnerella vaginalis)和阴道阿托波氏菌(Atopobium vaginae)的克隆子占较大比例, 且无乳酸杆菌克隆子。说明健康妇女阴道菌群的种类单一, 以乳酸杆菌占优势, L. iners为优势菌种之一; BV患者阴道菌群的种类复杂多样, 但均以Gardnerella vaginalis及Atopobium vaginae共同占优势。     

健康妇女及3例细菌性阴道病患者阴道菌群的非培养分析

根据Amsel标准及Nugent标准,确诊筛选健康妇女及细菌性阴道病(bacterial vaginosis,BV)患者各3例.提取其阴道分泌物样本的总DNA,构建16S rRNA基因克隆文库,并对阳性克隆进行ARDRA和测序分析.结果表明,健康妇女样本的基因文库中,分别以卷曲乳酸杆菌(L.crispatus)和惰性乳酸杆菌(L. iners)的克隆子占较大比例,另外存在少量的阴道乳酸杆菌(L.vaginalis)或詹氏乳酸杆菌(L.jensenii)的克隆子.BV患者样本的基因文库中,克隆子所代表的菌种类型明显增多,但均以阴道加德纳氏菌(Gardnerella vaginalis)和阴道阿托波氏菌(Atopobium vaginae)的克隆子占较大比例,且无乳酸杆菌克隆子.说明健康妇女阴道菌群的种类单一,以乳酸杆菌占优势,L. iners为优势菌种之一;BV患者阴道菌群的种类复杂多样,但均以Gardnerella vaginalis及Atopobium vaginae共同占优势.     

Risks for Acquisition of Bacterial Vaginosis Among Women Who Report Sex with Women: A Cohort Study

Background

Bacterial vaginosis (BV) is common in women who have sex with women. While cross-sectional data support a role for sexual transmission, risks for incident BV have not been prospectively studied in this group.

Methodology/Principal Findings

We studied risks for BV acquisition in a prospective cohort study of women (age 16–35 years) who reported sex with other women (≥1 partner, prior year). Women were followed for one year with examinations at quarterly visits and for genital symptoms at any time. Species-specific 16S rRNA gene PCRs for BV-associated bacteria (BVAB) were applied to vaginal fluid obtained at enrollment. Sexual behaviors were ascertained by computer-assisted interview. Of 335 participants, 239 had no BV at baseline; 199 were seen in follow-up (median follow-up 355 days, 4.0 visits/subject). Forty women experienced ≥1 BV episode. Risks for incident BV were presentation ≤14 days since onset of menses (hazard ratio (HR) 2.3 (95% CI, 1.2–4.7), report of new sex partner with BV history (HR 3.63 (1.1–11.9)), change in vaginal discharge (HR 2.6 (1.3–5.2)) and detection of any of several BVAB in vaginal fluid at enrollment, including BVAB1 (HR 6.3 (1.4–28.1)), BVAB2 (HR 18.2 (6.4–51.8)), BVAB3 (HR 12.6 (2.7–58.4)), G. vaginalis (HR 3.9 (1.5–10.4)), Atopobium vaginae (HR 4.2 (1.9–9.3)), Leptotrichia spp (9.3 (3.0–24.4)), and Megasphaera-1 (HR 11.5 (5.0–26.6)). Detection of Lactobacillus crispatus at enrollment conferred reduced risk for subsequent BV (HR 0.18 (0.08–0.4)). Detailed analysis of behavioral data suggested a direct dose-response relationship with increasing number of episodes of receptive oral-vulvovaginal sex (HR 1.02 (95% CI, 1.00–1.04).

Conclusions/Significance

Vaginal detection of several BVAB in BV-negative women predicted subsequent BV, suggesting that changes in vaginal microbiota precede BV by weeks or months. BV acquisition was associated with report of new partner with BV; associations with sexual practices – specifically, receptive oral sex – require further investigation.     

乌鲁木齐地区维吾尔族、汉族妇女细菌性阴道病对比分析

目的:探讨乌鲁木齐地区维吾尔族、汉族妇女细菌性阴道病患者的白细胞计数、中性粒细胞百分比、C反应蛋白的变化及其临床意义.方法:采用五分类血细胞分析仪检测乌鲁木齐地区128例维吾尔族和100例汉族细菌性阴道病妇女患者全血的白细胞计数和中性粒细胞百分比,采用免疫比浊法检测C反应蛋白的水平.所有患者阴道分泌物同时进行细菌性阴道病联合检测.结果:维吾尔族细菌性阴道病患者中性粒细胞百分比、C反应蛋白水平和唾液酸酐酶阳性率明显高于汉族患者(P＜0.05);两民族患者间白细胞计数、过氧化氢酶和白细胞酯酶的阳性率无统计学差异(P＞0.05).结论:乌鲁木齐地区维吾尔族、汉族细菌性阴道病患者的各有特点,临床应给予重视.     

Serum IgG Antibody Levels to Periodontal Microbiota Are Associated with Incident Alzheimer Disease

Background

Periodontitis and Alzheimer disease (AD) are associated with systemic inflammation. This research studied serum IgG to periodontal microbiota as possible predictors of incident AD.

Methods

Using a case-cohort study design, 219 subjects (110 incident AD cases and 109 controls without incident cognitive impairment at last follow-up), matched on race-ethnicity, were drawn from the Washington Heights-Inwood Columbia Aging Project (WHICAP), a cohort of longitudinally followed northern Manhattan residents aged >65 years. Mean follow-up was five years (SD 2.6). In baseline sera, serum IgG levels were determined for bacteria known to be positively or negatively associated with periodontitis (Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans Y4, Treponema denticola, Campylobacter rectus, Eubacterium nodatum, and Actinomyces naeslundii genospecies-2). In all analyses, we used antibody threshold levels shown to correlate with presence of moderate-severe periodontitis.

Results

Mean age was 72 years (SD 6.9) for controls, and 79 years (SD 4.6) for cases (p<0.001). Non-Hispanic Whites comprised 26%, non-Hispanic Blacks 27%, and Hispanics 48% of the sample. In a model adjusting for baseline age, sex, education, diabetes mellitus, hypertension, smoking, prior history of stroke, and apolipoprotein E genotype, high anti-A. naeslundii titer (>640 ng/ml, present in 10% of subjects) was associated with increased risk of AD (HR = 2.0, 95%CI: 1.1–3.8). This association was stronger after adjusting for other significant titers (HR = 3.1, 95%CI: 1.5–6.4). In this model, high anti-E. nodatum IgG (>1755 ng/ml; 19% of subjects) was associated with lower risk of AD (HR = 0.5, 95%CI: 0.2–0.9).

Conclusions

Serum IgG levels to common periodontal microbiota are associated with risk for developing incident AD.     

Levels of C-Reactive Protein Associated with High and Very High Cardiovascular Risk Are Prevalent in Patients with Rheumatoid Arthritis

Objective

C-reactive protein (CRP) levels>3 mg/L and>10 mg/L are associated with high and very high cardiovascular risk, respectively, in the general population. Because rheumatoid arthritis (RA) confers excess cardiovascular mortality, we determined the prevalence of these CRP levels among RA patients stratified on the basis of their RA disease activity.

Methods

We evaluated physician and patient global assessments of disease activity, tender and swollen 28 joint counts, erythrocyte sedimentation rate (ESR), and CRP measured in a single clinic visit for 151 RA patients. Disease activity was calculated using the Clinical Disease Activity Index (CDAI) and the Disease Activity Score 28 Joints (DAS28-ESR and DAS28-CRP).

Results

Median CRP level was 5.3 mg/L. 68% of patients had CRP>3 mg/L, and 25% had CRP>10 mg/L. Of those with 0–1 swollen joints (n = 56), or 0–1 tender joints (n = 81), 64% and 67%, respectively, had CRP>3 mg/L, and 23% and 20%, respectively, had CRP>10 mg/L. Of those with remission or mildly active disease by CDAI (n = 58), DAS28-ESR (n = 39), or DAS28-CRP (n = 70), 49–66% had CRP>3 mg/L, and 10–14% had CRP>10 mg/L. Of patients with moderate disease activity by CDAI (n = 51), DAS28-ESR (n = 78), or DAS28-CRP (n = 66), 67–73% had CRP>3 mg/L, and 25–33% had CRP>10 mg/L.

Conclusion

Even among RA patients whose disease is judged to be controlled by joint counts or standardized disease scores, a substantial proportion have CRP levels that are associated high or very high risk for future cardiovascular events in the general population.     

Visceral Obesity and Insulin Resistance Are Associated with Plasma Aldosterone Levels in Women

GOODFRIEND, THEODORE L., DAVID E. KELLEY, BRET H. GOODPASTER, AND STEPHEN J. WINTERS. Visceral obesity and insulin resistance are associated with plasma aldosterone levels in women. Obes Res. Objective: Both obesity and insulin resistance increase the risk of hypertension and other cardiovascular diseases, but the mechanisms linking these abnormalities are unknown. The current study was undertaken to examine the effects of obesity, fat distribution, and insulin resistance on plasma levels of aldosterone and other adrenal steroids that might contribute to sequelae of obesity. Research Methods and Procedures: Twenty-eight normo-tensive premenopausal women and 27 normotensive men with a wide range of body fat underwent measurements of visceral adipose tissue by CT scan, total fat mass by dual energy X-ray absorptiometry, blood pressure, insulin sensitivity, and plasma levels of three adrenal steroid hormones. Results: Plasma aldosterone in women correlated directly with visceral adipose tissue (r = 0. 66, p<0. 001) and inversely with insulin sensitivity (r = ?0. 67, p<0. 001), and these associations were independent of plasma renin activity. There were no corresponding correlations in men. Plasma aldosterone was significantly correlated with plasma cortisol and dehydroepiandrosterone sulfate in women. Seventeen women and 15 men completed a weight-reduction regimen, losing an average of 15. 1±1. 2 kg. After weight loss, plasma aldosterone was significantly lower and insulin sensitivity higher; however, the correlations of aldosterone with visceral adipose tissue and insulin sensitivity in women persisted (p = 0. 09 and 0. 07, respectively). Although none of the women were hypertensive, blood pressure correlated with plasma aldosterone both before and after weight loss. Discussion: We conclude that visceral adiposity and insulin resistance are associated with increased plasma aldosterone and other adrenal steroids that may contribute to cardiovascular diseases in obese women.     

HVEM Gene Polymorphisms Are Associated with Sporadic Breast Cancer in Chinese Women

As a costimulatory molecule, Herpesvirus entry mediator (HVEM) can bind with several costimulatory members, thus HVEM plays different roles in T cell immunity. HVEM and its ligands have been involved in the pathogenesis of various autoimmune, inflammatory diseases and tumors. In the current study, we conducted a case-control study comparing polymorphisms of HVEM and breast cancer. Subjects included 575 females with breast cancer and 604 age-matched healthy controls. Six HVEM SNPs (rs2281852, rs1886730, rs2234163, rs11573979, rs2234165, and rs2234167) were genotyped by PCR-RFLP. The results showed significant differences in genotypes and alleles between rs1886730 and rs2234167 (P<0.05). One haplotype (CTGCGG) that was associated with breast cancer was found via haplotype analysis. Our research also indicated an association between polymorphisms of HVEM and clinicopathologic features, including lymph node metastasis, estrogen receptor, progesterone receptor and P53. Our results primarily indicate that polymorphisms of the HVEM gene were associated with the risk of sporadic breast cancer in northeast Chinese females.     

Longitudinal Analysis of Vaginal Microbiome Dynamics in Women with Recurrent Bacterial Vaginosis: Recognition of the Conversion Process

Bacterial vaginosis (BV) affects ∼30% of women of reproductive age, has a high rate of recurrence, and is associated with miscarriage, preterm birth, and increased risk of acquiring other sexually transmitted infections, including HIV-1. Little is known of the daily changes in the vaginal bacterial composition as it progresses from treatment to recurrence, or whether any of these might be useful in its prediction or an understanding of its causes. We used phylogenetic branch-inclusive quantitative PCR (PB-qPCR) and Lactobacillus blocked/unblocked qPCR (Lb-qPCR) to characterize longitudinal changes in the vaginal microbiota in sequential vaginal self-swabs from five women with recurrent BV, from diagnosis through remission to recurrence. Both patients with acute BV samples dominated by G. vaginalis recurred during the study with similar profiles, whereas the three patients with acute BV samples dominated by other anaerobes did not recur or recurred to an intermediate Nugent score. L. iners dominated remission phases, with intermittent days of abnormal microbial profiles typically associated with menses. The exception was a newly discovered phenomenon, a sustained period of abnormal profiles, termed conversion, which preceded symptomatic acute BV. Species known to have antagonistic activity towards Lactobacillus were detected in pre-conversion samples, possibly contributing to the decline in Lactobacillus. Lb-qPCR scores define two categories of response in the initial post-treatment visit samples; scores <5 may correspond with poor response to treatment or rapid recurrence, whereas scores >8 may predict delayed or no recurrence. Amsel criteria or Nugent scores did not have this potential predictive capability. Larger studies are warranted to evaluate the prognostic potential of detecting conversion and poor Lb-qPCR scores at the post-treatment visit of recurrent BV patients.     

Trade-Offs Between Efficiency and Robustness in Bacterial Metabolic Networks Are Associated with Niche Breadth

The relation between structure and function in biologic networks is a central point of systems biology research. Key functional features—notably, efficiency and robustness—are linked to the topologic structure of a network, and there appears to be a degree of trade-off between these features, i.e., simulation studies indicate that more efficient networks tend to be less robust. Here, we investigate this issue in metabolic networks from 105 lineages of bacteria having a wide range of ecologies. We take quantitative measurements on each network and integrate this network data with ecologic data using a phylogenetic comparative model. In this setting, we find that biologic conclusions obtained with classical phylogenetic comparative methods are sensitive to correlations between model covariates and phylogenetic branch length. To avoid this problem, we propose a revised statistical framework—hierarchical mixed-effect regression—to accommodate phylogenetic nonindependence. Using this approach, we show that the cartography of metabolic networks does indeed reflect a trade-off between efficiency and robustness. Furthermore, ecologic characteristics related to niche breadth are strong predictors of network shape. Given the broad variation in niche breadth seen among species, we predict that there is no universally optimal balance between efficiency and robustness in bacterial metabolic networks and, thus, no universally optimal network structure. These results highlight the biologic relevance of variation in network structure and the potential role of niche breadth in shaping metabolic strategies of efficiency and robustness. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Ransom A. Myers Died March 27th, 2007. He will be missed.     

Bacterial Vaginosis Is Associated with Loss of Gamma Delta T Cells in the Female Reproductive Tract in Women in the Miami Women Interagency HIV Study (WIHS): A Cross Sectional Study

Bacterial vaginosis (BV) is the most common female reproductive tract infection and is associated with an increased risk of acquiring and transmitting HIV by a mechanism that is not well understood. Gamma delta (GD) T cells are essential components of the adaptive and innate immune system, are present in the female reproductive tract, and play an important role in epithelial barrier protection. GD1 cells predominate in the mucosal tissue and are important in maintaining mucosal integrity. GD2 cells predominate in peripheral blood and play a role in humoral immunity and in the immune response to pathogens. HIV infection is associated with changes in GD T cells frequencies in the periphery and in the female reproductive tract. The objective of this study is to evaluate if changes in vaginal flora occurring with BV are associated with changes in endocervical GD T cell responses, which could account for increased susceptibility to HIV. Seventeen HIV-infected (HIV+) and 17 HIV-uninfected (HIV-) pre-menopausal women underwent collection of vaginal swabs and endocervical cytobrushes. Vaginal flora was assessed using the Nugent score. GD T cells were assessed in cytobrush samples by flow cytometry. Median Nugent score was 5.0 and 41% of women had abnormal vaginal flora. In HIV uninfected women there was a negative correlation between Nugent score and cervical GD1 T cells (b for interaction = - 0.176, p<0.01); cervical GD1 T cells were higher in women with normal vaginal flora than in those with abnormal flora (45.00% vs 9.95%, p = 0.005); and cervical GD2 T cells were higher in women with abnormal flora than in those with normal flora (1.70% vs 0.35%, p = 0.023). GD T cells in the genital tract are protective (GD1) and are targets for HIV entry (GD2). The decrease in cervical GD1 and increase in GD2 T cells among women with abnormal vaginal flora predisposes women with BV to HIV acquisition. We propose to use GD T cell as markers of female genital tract vulnerability to HIV.