Evaluation of a fast test to identify the presence of proline aminopeptidase in women with bacterial vaginosis

The Immunomodulation Role of Vaginal Microenvironment On Human Papillomavirus Infection

BACKGROUND

Evidence suggests the role of the vaginal microbiome and microenvironment in the immunity state. The human papillomavirus (HPV) infection is widely dependent on the healthy vaginal microenvironment. Hence, this study aimed to investigate the role of the vaginal microenvironment in the rate of high-risk HPV (hr-HPV) infection.

MATERIALS AND METHODS

This cross-sectional study was performed on 512 women with hr-HPV positive (n=212) or negative (n=300) infection. The vaginal samples of women were examined regarding yeas and Gardnerella vaginalis infection. Also, Lactobacillus acidophilus, pH, and enzyme activity (such as catalase, proline aminopeptidase, and leucocyte esterase) were compared between the two groups. Also, the histopathological study was performed on the vaginal samples.

RESULTS

The higher rate of yeast and G. vaginalis infections as well as decreased L. acidophilus, were significantly observed in women with hr-HPV positive infection (P0.001). Also, histopathological findings indicated that cervical intraepithelial neoplasia grade I-III and cervical cancer lesions were markedly higher in hr-HPV positive group compared with control women.

CONCLUSION

The hr-HPV infection was markedly correlated to vaginal microenvironments, and it could a risk factor for the elevation of the rate of high-grade cervical lesions.

Evaluation of interobserver reliability of Nugent score for diagnosis of bacterial vaginosis

Background

Vaginal discharge is the commonly narrated compliant of the female attendees of sexually transmitted infection clinic, among which bacterial vaginosis (BV) is responsible for one-third of the visits. BV is often diagnosed clinically which warrants laboratory confirmation.

Aims

The study aims to detect the reliability of the Nugent scoring system between observers for the diagnosis of BV.

Materials and Methods

This is a prospective study including 177 high vaginal swabs. The gram-stained smears were examined by three independent microbiologists, and the Nugent scoring was performed. Statistical analysis was performed using IBM-SPSS version-22 statistical package for kappa value.

Results

Concordant results were seen in 64.03% of smears, discordant results were given in 4.51% of smears, and partial agreement was observed in 31.63% of smears.

Conclusion

Interobserver reliability is good for the Nugent score. The Nugent score is a simple and reliable method for the diagnosis of BV that can be adapted even in the resource poor settings.

Performance of BVBlue rapid test in detecting bacterial vaginosis among women in Mysore, India

Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in reproductive age women. It is associated with increased susceptibility to HIV/STI and adverse birth outcomes. Diagnosis of BV in resource-poor settings like India is challenging. With little laboratory infrastructure there is a need for objective point-of-care diagnostic tests. Vaginal swabs were collected from women 18 years and older, with a vaginal pH>4.5 attending a reproductive health clinic. BV was diagnosed with Amsel's criteria, Nugent scores, and the OSOM BVBlue test. Study personnel were blinded to test results. There were 347 participants enrolled between August 2009 and January 2010. BV prevalence was 45.1% (95% confidence interval (CI): 41.5%-52.8%) according to Nugent score. When compared with Nugent score, the sensitivity, specificity, positive predictive value, negative predictive value for Amsel's criteria and BVBlue were 61.9%, 88.3%, 81.5%, 73.7% and 38.1%, 92.7%, 82.1%, 63.9%, respectively. Combined with a "whiff" test, the performance of BVBlue increased sensitivity to 64.4% and negative predictive value to 73.8%. Despite the good specificity, poor sensitivity limits the usefulness of the BVBlue as a screening test in this population. There is a need to examine the usefulness of this test in other Indian populations.

Antibody-based detection and inhibition of vaginolysin, the Gardnerella vaginalis cytolysin

Bacterial vaginosis (BV) is the most common vaginal infection worldwide and is associated with significant adverse sequelae. We have recently characterized vaginolysin (VLY), the human-specific cytotoxin produced by Gardnerella vaginalis and believed to play a critical role in the pathogenesis of BV and its associated morbidities. We hypothesize that novel antibody-based strategies may be useful for detection of VLY and for inhibition of its toxic effects on human cells. Using purified toxin as an immunogen, we generated polyclonal rabbit immune serum (IS) against VLY. A western blot of G. vaginalis lysate was probed with IS and a single band (57 kD) identified. Immunofluorescence techniques using IS detected VLY production by G. vaginalis. In addition, we have developed a sandwich ELISA assay capable of VLY quantification at ng/ml concentrations in the supernatant of growing G. vaginalis. To investigate the potential inhibitory role of IS on VLY-mediated cell lysis, we exposed human erythrocytes to VLY or VLY pretreated with IS and determined the percent hemolysis. Pretreatment with IS resulted in a significant reduction in VLY-mediated lysis. Similarly, both human cervical carcinoma cells and vaginal epithelial cells exhibited reduced cytolysis following exposure to VLY with IS compared to VLY alone. These results confirm that antibody-based techniques are an effective means of VLY detection. Furthermore, VLY antiserum functions as an inhibitor of VLY–CD59 interaction, mitigating cell lysis. These strategies may have a potential role in the diagnosis and treatment of BV.