Male sex predominance in Chlamydia trachomatis sexually acquired reactive arthritis: are women more protected by anti-chlamydia antibodies?

Sex and Gender Differences in Bacterial Infections

There is a growing awareness of the importance of sex and gender in medicine and research. Women typically have stronger immune responses to self and foreign antigens than men, resulting in sex-based differences in autoimmunity and infectious diseases. In both animals and humans, males are generally more susceptible than females to bacterial infections. At the same time, gender differences in health-seeking behavior, quality of health care, and adherence to treatment recommendations have been reported. This review explores our current understanding of differences between males and females in bacterial diseases. We describe how genetic, immunological, hormonal, and anatomical factors interact to influence sex-based differences in pathophysiology, epidemiology, clinical presentation, disease severity, and prognosis, and how gender roles affect the behavior of patients and providers in the health care system.

Higher Levels of Secretory IgA Are Associated with Low Disease Activity Index in Patients with Reactive Arthritis and Undifferentiated Spondyloarthritis

Introduction

Both reactive arthritis (ReA) and undifferentiated spondyloarthritis (uSpA) belong to the group of autoinflammatory diseases called spondyloarthritis (SpA). Hypotheses have been proposed about a relationship between the intestinal mucosa and inflammation of joint tissues. The role of immunoglobulin IgA or secretory immunoglobulin A (SIgA) in the inflammatory and/or clinical activity of patients with SpA remains poorly understood.

Objective

To evaluate the status of total IgA and SIgA, and the association among the levels of SIgA, IgA, IgA anti-Chlamydia trachomatis, and anti-Shigella spp. with the disease activity measures, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels, was compared in a cohort of patients with ReA and uSpA and healthy subjects.

Methods

This was a cross-sectional study. The serum concentrations of SIgA, IgA anti-C. trachomatis, anti-Shigella spp., and total IgA were measured. Disease activity was measured in each patient by means of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS). Statistical analysis did include as bivariate evaluation, comparisons by Student’s t-test, Kruskal–Wallis test, and U Mann–Whitney test, with a multivariate evaluation by principal components analysis (PCA). A correlation analysis was carried out using the Pearson correlation coefficient and a linear regression models. All analysis were made using Stata version 11.2^® for Windows, R V3.3.21. Statistical significance was defined a p-value <0.05.

Results

In all, 46 patients (78.2% men; mean age, 34.8 ± 12.3 years) and 53 controls (41% men; mean age, 32 ± 11.4 years) were included in the study. The mean serum levels of SIgA were higher in SpA patients than in healthy subjects (p < 0.001). Only SIgA levels correlated with disease activity: BASDAI (r = −0.42, p = 0.0046), ASDAS-CRP (r = −0.37, p = 0.014), and ASDAS-ESR (r = −0.45, p = 0.0021). The negative correlation between SIgA and all activity indices was higher in HLA-B27-positive patients (BASDAI r = −0.70, p = 0.0009, ASDAS-CRP r = −0.58, p = 0.0093, and ASDAS-ESR r = −0.57, p = 0.0083). The PCA showed three factors: the first component was constituted by variables referred as clinical activity measures, the second did include the serological activity markers, and the last component was compounded by age and symptoms time.

Conclusion

Elevated serum levels of SIgA were found to be related with low disease activity in patients with ReA and uSpA.

Do IgA antibodies to Chlamydia trachomatis have protective role in humoral immunity: a study in reactive arthritis patients

Chlamydia trachomatis-induced genitourinary Reactive Arthritis (ReA) can serve as good model for host-pathogen interaction. However, due to poor antigen presentation, cell-mediated immunity does not contribute as anticipated. Present study aims to evaluate protective role of anti-C. trachomatis antibodies vis-a-vis inflammatory chlamydial Major Outer Membrane Protein (MOMP). Prospective study was undertaken in 30 patients with genitourinary ReA. 30 Rheumatoid Arthritis (RA) and 30 osteoarthritis patients constituted controls. Subjects found to be PCR-positive for C. trachomatis were investigated for presence of MOMP in Synovial Fluid (SF) by fluorescence assay while anti-C. trachomatis IgA/IgM antibodies were estimated in SF/venous blood by ELISA. C. trachomatis MOMP was evident by the presence of elementary bodies in SF of 9 ReA PCR-positive patients (30%; p < 0.05 versus controls). Local secretory IgA antibodies were detected in 12 (40%) patients with ReA (p < 0.0001 versus controls); among 12 patients with anti-chlamydial IgA antibodies, 9 showed the presence of both MOMP and IgA antibodies in SF. 58.3% ReA patients (7/12) with secretory IgA antibodies were also positive for circulatory IgA antibodies (p < 0.01 versus controls). Serum IgM antibodies were present in 4 ReA (13.3%) and in 1 RA (3.3%) patient, respectively. In conclusion, the present study suggests that in ReA patients with chronic, persistent C. trachomatis infection in synovium, the chlamydial MOMP is triggering factor for generating a protective immune response by inducing anti-C. trachomatis IgA antibodies in the SF of large number of patients.

Prevalence of antibodies against Chlamydia trachomatis and incidence of C. trachomatis-induced reactive arthritis in an early arthritis series in Finland in 2000

OBJECTIVE

To study the prevalence of different serotypes of Chlamydia trachomatis antibodies and the incidence of C. trachomatis-induced reactive arthritis (ReA) among patients with early arthritis in a defined population.

METHODS

Serum samples were collected from a cohort of 122 adult patients in the age group 18-65 years included in the Kuopio 2000 Arthritis Survey. Antibodies against C. trachomatis serotypes C, E, and G were studied using enzyme immunoassay (EIA) tests among patients and in a control cohort of 78 adults without any joint symptoms. The incidence assessment for Chlamydia-induced ReA was based on a ligase chain reaction (LCR) test in urine and clinical symptoms and signs appropriate for ReA.

RESULTS

Of 122 patients, with the baseline diagnosis of rheumatoid arthritis (RA) in 11, spondyloarthropathy (SpA) in 28, and undifferentiated arthritis (UA) in 83 cases, 42 (34%) showed immunoglobulin (Ig)G or IgA antibodies against at least one serotype C, E, or G. Among the patients with UA the prevalence was significantly increased compared with the controls (p = 0.010). C. trachomatis-induced ReA arthritis was diagnosed in only three patients with the LCR test. On this basis the incidence of C. trachomatis-induced arthritis was 5.4/100 000 [95% confidence interval (CI) 1.1-15.7] in the age group 18-65 years.

CONCLUSION

Antibodies against C. trachomatis were most common in patients with UA reflecting the fact that cases with chlamydia-induced ReA are included in this subgroup.

Reactive arthritis: a review

This review article summarizes the available literature on adolescent reactive arthritis. A review of the pathophysiology, diagnosis, and treatment guidelines will be helpful to better diagnose and treat reactive arthritis.

Reactive arthritis

ReA consists of sterile axial or peripheral articular inflammation,enthesitis, and extra-articular manifestations. Most patients are HLA-B27 positive, although determining the B27 status of an individual patient is irrelevant. Exposure to specific bacterial antigens is usually the inciting factor. Diagnosis usually can be made by clinical examination and history. The current standard therapy is NSAIDs and physiotherapy, but molecular biologic treatment may ultimately become the mainstay in recalcitrant and severe ReA.

Reactive arthritis: newer developments

Reactive arthritis (ReA) is characterized by an aseptic inflammatory articular involvement occurring in a genetically predisposed individual secondary to an infectious process localized outside the joint. ReA usually refers to an acute or insidious oligoarthritis process after enteric (enteroarthritis) or urogenital (uroarthritis) infection. Conventional antirheumatic therapeutic modalities based on nonsteroid anti-inflammatory drugs, sulfasalazine, and steroids are effective in the majority of patients. In more refractory cases, the use of second-line agents including methotrexate and more recently biological agents such as etanercept and infliximab has been found highly effective. The role of antibiotics remains not well established, although they appear to be effective in acute ReA of urogenital origin.

Seronegative spondyloarthritides

Epidemiological studies on the spondyloarthritides have been hindered in the past by the lack of adequate classification criteria for the whole group of these diseases. Using the Amor and the European Spondyloathropathy Study Group (ESSG) criteria the total prevalence of such diseases has been found to be higher than estimated in the past. The prevalence of ankylosing spondylitis varies across populations, but closely parallels the frequency of HLA B27-associated subtypes. The lack of well established criteria for reactive arthritis and the varying expression of its clinical manifestations are the principal reasons for the under-reporting of the true prevalence and incidence of this type of spondyloarthritis. Few data exist on the prevalence and incidence of psoriatic arthritis. A recent European study on an inception cohort of patients having inflammatory bowel disease has evaluated the prevalence of spondyloarthritis using the ESSG criteria. Of the patients studied, 18% met these criteria. Undifferentiated spondyloarthritis is one of the most frequent spondyloarthritides. It also includes a number of different subtypes.

Indirect evidence of intra-articular immunoglobulin G synthesis in patients with Chlamydia trachomatis reactive arthritis

OBJECTIVES

To investigate whether B-cell stimulation occurs in joints of Chlamydia trachomatis reactive arthritis patients by comparing the immunoglobulin G (IgG) anti-C. trachomatis antibody responses in serum and synovial fluid (SF).

METHODS

The number and spectrum of C. trachomatis antigens recognized by paired serum and SF samples from 16 patients with C. trachomatis reactive arthritis and 20 patients with other inflammatory arthropathies independent of this bacteria, were studied by immunoblotting. The responses to five different Chlamydia antigens were also determined in enzyme-linked immunosorbent assays.

RESULTS

In C. trachomatis reactive arthritis patients, a higher number of C. trachomatis antigens was recognized by SF (17.6+/-5.1) than by serum (11.1+/-6.3) IgG and a higher intensity of SF IgG binding to the outer membrane protein 2 (OMP2) was observed.

CONCLUSIONS

These results suggest an intra-articular IgG production and a possible role of some Chlamydia antigens like OMP2 in the pathogenesis of C. trachomatis reactive arthritis.

Chlamydial serology: comparative diagnostic value of immunoblotting, microimmunofluorescence test, and immunoassays using different recombinant proteins as antigens

To improve the reliability of the serodiagnosis of Chlamydia trachomatis infections, an immunoblot analysis, a microimmunofluorescence titration, and different immunoassays using synthetic peptides derived from species-specific epitopes in variable domain IV of the major outer membrane protein or recombinant antigens (heat shock protein 70 [hsp70], hsp60, hsp10, polypeptide encoded by open reading frame 3 of the plasmid [pgp3], macrophage infectivity potentiator, and a fragment of the total lipopolysaccharide) were evaluated. Because cross-reactions between chlamydial species have been reported, the microimmunofluorescence tests were also performed with Chlamydia pneumoniae and Chlamydia psittaci used as antigens, and C. pneumoniae-specific antibodies were also determined by immunoassays. Since the presence of antimicrobial antibodies must be interpreted in light of their prevalence in the general population, responses obtained with serum samples from patients with well-defined infection (i.e., with positive urethral or endocervical C. trachomatis DNA amplification) were compared to those obtained with samples from healthy blood donors. The best sensitivity (86%) with a specificity of 81% was obtained for immunoblotting results, when the number of individuals with > or =10 immunoglobulin G (IgG) and/or > or =2 IgM responses to the different C. trachomatis antigens was considered. A 13-kDa antigen was recognized by most of the samples (86% for IgG) from patients with acute urogenital infection but rarely (3%) by those from healthy blood donors (P < 0.0001). The sensitivity and specificity results obtained for serum antibodies to peptides or recombinant antigens were slightly lower than those results obtained for the number of responses to whole C. trachomatis antigens, which were 76 and 77%, respectively, when IgG responses to both recombinant hsp60 and pgp3 were considered.