Lymphogranuloma venereum outbreak in Europe

Antibody, but not B-cell-dependent antigen presentation, plays an essential role in preventing Chlamydia systemic dissemination in mice

The obligate intracellular bacterium Chlamydia trachomatis causes the most prevalent bacterial sexually transmitted infection worldwide. CD4 T cells play a central role in the protective immunity against Chlamydia female reproductive tract (FRT) infection, while B cells are thought to be dispensable for resolution of primary Chlamydia infection in mouse models. We recently reported an unexpected requirement of B cells in local Chlamydia-specific CD4 T-cell priming and bacterial containment within the FRT. Here, we sought to tackle the precise effector function of B cells during Chlamydia primary infection. Using mixed bone marrow chimeras that lack B-cell-dependent Ag presentation (MHCII^B - / - ) or devoid of circulating antibodies (AID^-/- × μS^-/- ), we show that Chlamydia-specific CD4 T-cell expansion does not rely on Ag presentation by B cells. Importantly, we demonstrate that antibody, but not B-cell-dependent Ag presentation, is required for preventing systemic bacterial dissemination following Chlamydia FRT infection.

Prevalence of Anal Fistulas in Europe: Systematic Literature Reviews and Population-Based Database Analysis

Introduction

Despite the fact that perianal fistulas are associated with significant morbidity and impaired quality of life, their prevalence in Europe is unknown. The aim of this study was to estimate the prevalence of perianal fistulas in Europe, overall and according to etiology.

Methods

Two independent literature reviews were performed using different search strategies to maximize the identification of potentially relevant studies. Data from relevant articles were used to estimate the prevalence of perianal fistulas in Europe. The robustness of the estimate was evaluated using data from a large population-based database from the UK.

Results

A total of 26 studies provided epidemiological data on perianal fistulas, of which 16 provided suitable data to estimate the prevalence. Estimations using these data yielded a total prevalence of 1.69 per 10,000 population. Cryptoglandular infection and Crohn’s disease (CD) were the predominant etiologies, with prevalence rates at 0.86 and 0.76 per 10,000 population, respectively. Comparison of prevalence data from the UK population-based database with the European population resulted in a standardized prevalence estimate of all perianal fistulas of 1.83 per 10,000 population, confirming the robustness of the literature-based estimate.

Conclusion

Although in terms of incidence cryptoglandular fistulas were clearly predominant, the prevalence of fistulas in CD and cryptoglandular infection appeared more balanced. This is due to the longer duration and higher frequency of relapses of fistulas in CD. The estimated prevalence implies that perianal fistulas meet the criteria to be considered as a rare condition in Europe (prevalence less than 5 per 10,000 population).

Funding

This study was funded by Takeda Pharmaceutical U.S.A., Inc. and TiGenix SAU.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-019-01117-y) contains supplementary material, which is available to authorized users.

A path forward for the chlamydial virulence factor CPAF

CPAF is a conserved and secreted protease from obligate intracellular bacteria of the order Chlamydiales. Recently, it was demonstrated that most of its host targets are an artifact of inaccurate methods. This review aims to summarize key features of CPAF and propose new approaches for evaluating its role in chlamydial pathogenesis.

Lymphogranuloma venereum proctosigmoiditis is a mimicker of inflammatory bowel disease

There has been an increasing prevalence of lymphogranuloma venereum (LGV) or Chlamydia trachomatis (C. trachomatis) cases among the men who have sex with men (MSM) population, particularly in Europe and North America. These cases may present with an incomplete or undisclosed history and proctosigmoiditis without characteristic adenopathy syndrome. During the initial evaluation and colonoscopy, there is a strong clinical and endoscopic suspicion of inflammatory bowel disease (IBD) by virtue of presentation and endoscopic and histological findings. The diagnosis of IBD is subsequently modified to LGV proctosigmoiditis when one or more of the following transpire: (1) there is failure of response to IBD therapy; (2) additional components of history (MSM/travel) may be identified; (3) return of initially performed Chlamydia antibody test is positive; and (4) response to antibiotics effective against Chlamydia. We describe three such cases initially suspected to be an inflammatory bowel disease and subsequently identified as C. trachomatis proctosigmoiditis.

Surveillance of sexually transmitted infections among persons living with HIV

OBJECTIVES

Surveillance of sexually transmitted infections (STI) among HIV patients in AIDS Reference Centers aims at identifying risk groups and detecting specific STI emerging in this population.

METHODS

Seven of the nine AIDS Reference Centers in Belgium participate in this surveillance. The reported STI include Chlamydia, gonorrhea, syphilis, Lymphogranuloma venereum, hepatitis B virus and newly acquired hepatitis C in men who have sex with men (MSM).

RESULTS

In 2008, 252 HIV patients (250 men, 2 women) were reported with a new STI episode. Sexual orientation was known for 245 men: 241 were MSM, 4 were heterosexual men. In total, 279 new STI episodes were reported. More than half of the diagnoses were syphilis. In 78% of the syphilis cases, the motive of the consultation was not related to an STI complaint.

CONCLUSIONS

The results underline the importance of regular STI screening among HIV-positive persons, and show a particular sexual health problem among MSM. We estimate that the proportion of HIV-positive MSM acquiring an STI in 2008 was 8.8%.

Development and evaluation of an ompA quantitative real-time PCR assay for Chlamydia trachomatis serovar determination

Knowledge of circulating Chlamydia trachomatis serovars can be beneficial for sexual network surveillance, monitoring treatment success, and associating specific clinical manifestations. Typically, C. trachomatis serovars are predicted by nucleotide sequencing of four variable domains within the ompA gene. However, sequencing procedures can be labor-intensive, are not readily available, and can lack the capacity to identify multiple serovars. This study describes the development and evaluation of a quantitative real-time PCR (qPCR) test algorithm for the rapid prediction of C. trachomatis serovars, including ocular (A to C) and anogenital (D to L3) strains. This test comprises a primary qPCR to confirm C. trachomatis positivity and the phylogenetic group(s) present and a secondary set of qPCRs to determine specific serovars. Cell culture isolates from 15 prototypic C. trachomatis serovars were correctly identified using this assay, with no cross-reactivity observed among serovars or with other common pathogenic microorganisms. Five hundred clinical specimens (previously diagnosed as being C. trachomatis positive) were evaluated by qPCR, with their results compared to results obtained by conventional sequencing. The qPCR identified 88.9% (423/476) complete matches (95% confidence interval [CI], 86 to 92%) of serovars compared to the results obtained using the sequence-based approach. Among the anogenital specimens, 2.4% (12/494) (95% CI, 1.3 to 4.2%) contained multiple serovars, categorized as single-serovar infections by conventional sequencing. Overall, this test exhibited high discriminatory success for predicting C. trachomatis serovars, particularly among anogenital infections. This is the first report of a qPCR typing assay offering differentiation of C. trachomatis serovars associated with both anogenital and ocular diseases.