Chlamydia trachomatis and herpes simplex virus IgA antibodies in cervical secretions of patients with cervical atypia

Association between human herpesvirus infection and cervical carcinoma: a systematic review and meta-analysis

BACKGROUND

Cervical cancer (CC) is one of the most common gynecologic tumors among women around the world. Although the etiological role of human papillomavirus (HPV) in CC is well established, other factors in CC carcinogenesis remains unclear. Here, we performed a systematic review and meta-analysis to explore the association between infections of human herpesvirus (HHVs) and CC risk.

METHODS

Embase and PubMed databases were utilized to search the relevant studies. The revised JBI Critical Appraisal Tool was used to assess the quality of the included studies. Prevalence and odds ratios (ORs) with 95% confidence intervals (CI) were calculated to evaluate the association between viral infection and CC or precancerous cervical lesions (PCL).

RESULTS

Totally 67 eligible studies involving 7 different HHVs were included in meta-analysis. We found an increased risk of CC or PCL that was associated with the overall infection of HHVs (CC, OR = 2.74, 95% CI 2.13-3.53; PCL, OR = 1.95, 95% CI 1.58-2.41). Subgroup analysis showed a trend towards positive correlations between herpes simplex virus type 2 (HSV-2) infection and CC (OR = 3.01, 95% CI 2.24 to 4.04) or PCL (OR = 2.14, 95% CI 1.55 to 2.96), and the same is true between Epstein-Barr virus (EBV) infection and CC (OR = 4.89, 95% CI 2.18 to 10.96) or PCL (OR = 3.55, 95% CI 2.52 to 5.00). However, for HSV-1 and cytomegalovirus (HCMV), there was no association between viral infection and CC or PCL. By contrast, the roles of HHV-6, HHV-7, and Kaposi sarcoma-associated herpesvirus (KSHV) in cervical lesions were unclear due to the limited number of studies.

CONCLUSIONS

This study provided evidence that HHVs infection as a whole increase the risk of CC incidence. In addition, some types of HHVs such as EBV and HSV-2 may serve as potential targets in the development of new interventions or therapeutic strategies for cervical lesions.

When Bacteria and Viruses Collide: A Tale of Chlamydia trachomatis and Sexually Transmitted Viruses

The global incidence of sexually transmitted infections (STIs) remains high, with the World Health Organization (WHO) estimating that over 1 million people acquire STIs daily. STIs can lead to infertility, pregnancy complications, and cancers. Co-infections with multiple pathogens are prevalent among individuals with an STI and can lead to heightened infectivity and more severe clinical manifestations. Chlamydia trachomatis (CT) is the most reported bacterial STI worldwide in both men and women, and several studies have demonstrated co-infection of CT with viral and other bacterial STIs. CT is a gram-negative bacterium with a unique biphasic developmental cycle including infectious extracellular elementary bodies (EBs) and metabolically active intracellular reticulate bodies (RBs). The intracellular form of this organism, RBs, has evolved mechanisms to persist for long periods within host epithelial cells in a viable but non-cultivable state. The co-infections of CT with the most frequently reported sexually transmitted viruses: human immunodeficiency virus (HIV), human papillomavirus (HPV), and herpes simplex virus (HSV) have been investigated through in vitro and in vivo studies. These research studies have made significant strides in unraveling the intricate interactions between CT, these viral STIs, and their eukaryotic host. In this review, we present an overview of the epidemiology of these co-infections, while specifically delineating the underlying mechanisms by which CT influences the transmission and infection dynamics of HIV and HSV. Furthermore, we explore the intricate relationship between CT and HPV infection, with a particular emphasis on the heightened risk of cervical cancer. By consolidating the current body of knowledge, we provide valuable insights into the complex dynamics and implications of co-infection involving CT and sexually transmitted viruses.

Chlamydia Trachomatis Infection-Associated Risk of Cervical Cancer: A Meta-Analysis

As whether Chlamydia trachomatis infection increases the risk of cervical cancer is controversial in the literature, we performed a meta-analysis.Based on a comprehensive search of publications in the Medline, Cochrane, and EMBASE databases, we identified and extracted data from all relevant articles examining C. trachomatis infection and the risk of cervical cancer. The quality of each included study was assessed according to the 9-star Newcastle-Ottawa scale. The strength of association between the C. trachomatis and risk of cervical cancer was estimated by odds ratio (OR) and 95% confidence intervals (CIs). This review was registered at PROSPERO with registration No. CRD42014015672. A total of 22 studies with 4291 cervical cancer cases and 7628 controls were identified. Overall, C. trachomatis was significantly linked to increased cervical cancer risk in prospective studies (OR = 2.21, 95% CI: 1.88-2.61, P < 0.001), as well as in retrospective studies (OR = 2.19, 95% CI: 1.74-2.74, P < 0.001). Additionally, with a multivariate logistic regression analysis adjusted for HPV and age, C. trachomatis infection was identified as an independent predictor of cervical cancer in 11 studies (OR = 1.76, 95% CI: 1.03-3.01, P = 0.04). Coinfection of human papilloma virus and C. trachomatis has a higher risk of cervical cancer (OR = 4.03, 95% CI: 3.15-5.16, P < 0.001). A subgroup analysis based on histological type indicated an elevated risk for both squamous cell carcinoma (OR = 2.21, 95% CI: 2.00-2.45, P < 0.001), and adenocarcinoma (OR = 1.61, 95% CI: 1.21-2.15, P = 0.001), in associated with C. trachomatis. Subgroup analysis by where C. trachomatis infection was detected showed a significantly higher risk of cervical cancer associated with C. trachomatis infection detected in serum (OR = 2.20, 95% CI: 2.01-2.42, P < 0.001), cervical tissue blocks (OR = 2.88, 95% CI: 1.21-6.83, P = 0.02), and cervical secretion (OR = 2.71, 95% CI: 1.41-5.20, P = 0.003), especially in serum with no obvious heterogeneity.In conclusion, our novel data demonstrate that individuals infected with C. trachomatis have a higher risk of cervical cancer. Therefore, it is necessary to expand C. trachomatis infection screening and treat women with C. trachomatis promptly, particularly those with human papilloma virus infections. This approach will not only protect against pelvic inflammatory disease and infertility, but may also prevent cervical cancer.

Class-specific herpes simplex virus antibodies in sera and cervical secretions from patients with cervical neoplasia: a multi-group comparison

Serum and cervical secretions were collected from patients with cervical dysplasia, carcinoma-in-situ (CIS), squamous cell carcinoma (cervical SCC), and controls with normal cervices, attending clinics within the West Lambeth Health District, London. Enzyme-linked immunosorbent assays were used to examine cervical secretory IgA (sIgA) and serum IgG and IgA antibodies to herpes simplex virus (HSV). Sexual and demographic factors were considered during data analysis, which involved fitting multiple linear or multiple logistic regressions to HSV antibody levels. Prevalence of sIgA-HSV and levels of serum antibodies to HSV in all groups were compared with those of gynaecology controls. Caucasian women with mild dysplasia had a significantly higher prevalence of sIgA-HSV. Serum IgG levels to HSV (IgG-HSV) were significantly elevated in women with mild dysplasia and severe dysplasia/CIS. Serum IgA levels to HSV1 (IgG-HSV1) were significantly higher in women with cervical SCC (after adjusting for smoking habits) and other genital tumours. Significantly higher levels of serum IgA to HSV2 (IgA-HSV2) were also found among Caucasian women with cervical SCC. The possible role of HSV as a co-factor in cervical carcinogenesis is discussed.

Diagnosis of intrauterine infection by demonstration of antibody-coated bacteria in the amniotic fluid

Immunofluorescence examination of amniotic fluid for the occurrence of antibody-coated bacteria was carried out in 72 consecutive women with premature rupture of the fetal membranes to assess this method in the diagnosis of intrauterine infection. Antibody-coated bacteria were demonstrated in 11 women with clinical signs of intrauterine infection, histological amnionitis and heavy growth of one bacterial species. The presence of intrauterine infection was considered possible in another 14 women. One patient had no clinical signs of infection, but positive histological and bacteriological evidence; antibody-coated bacteria were demonstrated in this patient, but not in the remaining 13 women. In 47 women clinical, histological and bacteriological signs of intrauterine infection were absent, and examinations for antibody-coated bacteria were negative in all of them. It is concluded that the demonstration of antibody-coated bacteria in amniotic fluid indicates the presence of intrauterine infection, and the examination may in some cases be positive before the appearance of clinical signs of infection.

Microbiology of vaginitis associated with the intrauterine contraceptive device

A malodorous, homogeneous, grey, thin and non-purulent discharge, which resembles non-specific vaginitis occurs in 20% of women with an intrauterine contraceptive device (IUCD); four times more common than in non-users. The aim of this investigation was to study the bacteriological aetiology of this IUCD-associated vaginal discharge, and to assess whether the infection was ascendent. No specific microbiological aetiology was found, but the normal, Lactobacillus-dominated microbial vaginal flora was replaced by Gardnerella vaginalis and certain anaerobic species in IUCD-users with the discharge. Clue cells, pepper-salt phenomenon and curved rods and/or fusiform-shaped rods demonstrated by microscopy, were typical of symptomatic patients. The endometrium and the IUCD were infected with these species in the symptomatic group more often than in IUCD-users who had no symptoms or in the control women who did not use the IUCD.

Cervical and serum IgA and serum IgG antibodies to Chlamydia trachomatis and herpes simplex virus in threatened abortion: a prospective study

The aetiological role of Chlamydia trachomatis (CT) and herpes simplex virus (HSV) was investigated in 189 patients with threatened abortion. Assessment of infection was based on isolation, and on determination of serum immunoglobulin (Ig)G and IgA antibodies as well as cervical IgA antibody levels with new sensitive radioimmunoassay (RIA) techniques. One third of the women were delivered of a healthy infant and two thirds aborted, but the two groups were otherwise clinically similar. By isolation, only 2.7% of the patients were CT-positive, but increased cervical IgA antibody level to CT was detected in 41.3%. The mean level of these local antibodies was similar in both study groups, but the mean levels of serum IgA and IgG antibodies were somewhat higher in the patients who aborted although the difference was not significant. None of the cervical specimens was positive for HSV by isolation but the cervical IgA antibody level to HSV was raised in 47.1% of the patients. Both cervical and serum IgA antibody levels to HSV were significantly raised among the patients who aborted, but there were no differences between the patients with spontaneous abortion and those with a blighted ovum. There was no clear association between CT and abortion, but an association between HSV and abortion is possible. The incidence of raised levels of both CT and HSV IgA antibodies in the cervix was surprisingly high in both groups and the significance of this finding remains to be investigated.