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PubMedDate not supplied

Examination of men with nongonococcal urethritis and their sexual partners for Chlamydia trachomatis and Ureaplasma urealyticum.

Chlamydia trachomatis was recovered from 39 (52%) of 75 men who had nongonococcal urethritis and from 28 (37%) of their sexual partners. Of the partners of men with Chlamydia-positive nongonococcal urethritis, 64% excreted Chlamydia, compared with 8% of the partners of men with Chlamydia-negative nongonococcal urethritis. In contrast, an apparently sexual mode of transmission was not observed with Ureaplasma urealyticum. Rates of recovery of U. urealyticum from men with nongonococcal urethritis whose cultures were Chlamydia-positive and those whose cultures were Chlamydia-negative were the same. Significant seroconversion was detected bythe single-antigen immunofluorescence test in about 50% of patients who had Chlamydia-postive cultures.

Adult↗
PubMedDate not supplied

The influence of sexual and social factors on the risk of Chlamydia trachomatis infections: a population-based serologic study.

BACKGROUND: Genital chlamydia infections often are asymptomatic, which promotes their spread in the population. In women, the possible consequences of infection are pelvic inflammatory disease and infertility. Most studies on the prevalence of Chlamydia trachomatis have been based on clinical series, and prevalences tend to vary with the clinical setting. Few seroepidemiologic studies have emerged from industrialized countries. GOAL OF THIS STUDY: To assess the prevalence of Chlamydia trachomatis using culture and serology, and its relationship with possible risk factors. STUDY DESIGN: This was a population-based study involving completion of a self-administered questionnaire, analysis of cervical samples for Chlamydia trachomatis, and serologic tests for Chlamydia trachomatis antibodies. RESULTS: The prevalence of Chlamydia trachomatis infection was 2.7%, and the seroprevalence was 24.7% among the sexually active women. Seropositivity was correlated with sexual behavior variables, and the incidence of serologic cross-reactivity with respiratory infections (strain TWAR) was low. Multivariate logistic regression analysis showed the number of sexual partners, age at first coitus, history of therapeutic abortion, and previous pelvic inflammatory disease to be independently correlated with seropositivity. CONCLUSION: Early sexual experience and multiple lifetime sexual partners are independent risk factors for Chlamydia trachomatis infection.

Adult↗
PubMedDate not supplied

A tale of two sexually transmitted diseases. Prevalences and predictors of chlamydia and gonorrhea in women attending Colorado family planning clinics.

BACKGROUND: The comparative prevalences and predictors of chlamydia and gonorrhea have not been studied in the family planning clinic population. GOALS: To determine the comparative prevalences and predictors of chlamydia and gonorrhea among Colorado family planning clinic patients. STUDY DESIGN: Cross-sectional study of public and private family planning clinic patients in Colorado tested for both chlamydia and gonorrhea (n = 12,926). RESULTS: Among women tested for both infections, the chlamydia prevalence rate was 4.5% and the gonorrhea prevalence rate was 0.5%. Multivariate analysis showed that independent predictors of chlamydia were age younger than 25 years, black or Hispanic race-ethnicity, cervical friability, mucopus, exposure to a sex partner with chlamydia, or multiple recent sex partners. Independent predictors of gonorrhea were age younger than 20 years, black or Hispanic race-ethnicity, or exposure to a sex partner with gonorrhea; adjusted odds ratios for exposure to gonorrhea and black race were the highest for either infection. CONCLUSIONS: The gonorrhea prevalence rate was very low compared to that of chlamydia in patients at Colorado family planning clinics. Cost-effective gonorrhea testing strategies are needed for this population.

Adult↗
PubMed2002

Incidence and repeat infection rates of Chlamydia trachomatis among male and female patients in an STD clinic: implications for screening and rescreening.

BACKGROUND: Nucleic acid amplification tests permit widespread screening for Chlamydia trachomatis. However, the public health benefit of screening may be reduced by high chlamydia incidence and repeat infection rates. GOAL: To study chlamydia incidence and repeat infection among clients of a sexually transmitted disease (STD) clinic. STUDY DESIGN: A retrospective cohort study of all clients tested for chlamydia on two or more occasions during a 30-month period. RESULTS: Between January 1, 1997 and June 30, 1999, 3568 clients were tested on multiple occasions. Of these, 491 (13.8%) had positive test results at their first visit (baseline infections), and 385 (10.8%) had positive results at a subsequent visit (incident infections). The overall incidence was 11.7 per 100 person-years of follow-up evaluation (95% CI, 10.6-12.9). The incidence was significantly higher among those 25 years of age or younger (19.7/100 person-years; 95% CI, 17.3-22.2) than among older subjects (6.8/100 person-years, 95% CI, 5.7-7.9; relative hazard, 3.0; 95% CI, 2.5-3.7). The incidence of new infections among persons without a baseline infection was 10.0 per 100 person-years (95% CI, 8.8-11.2), whereas the incidence of repeat infections was 23.6 per 100 person-years (95% CI, 18.9-28.2; relative hazard, 2.4; 95% CI, 1.9-3.0), with repeat infections accounting for 26% of all incident infections. In the multivariate analysis, the factors associated with new infections included young age, black race, male gender, history of sexually transmitted disease, a new sex partner in the previous 30 days, and inconsistent condom use. The factors associated with repeat infection were younger age, nonuse of condoms, and no treatment after contact with a partner who had a diagnosis of chlamydia or a chlamydia-related condition, as measured at the initial visit. CONCLUSIONS: Among clients making multiple visits to the clinic, repeat infection rates were significantly higher than new infection rates, likely because of reexposure to untreated partners. These findings point to the need for more effective strategies to prevent chlamydia infection, including enhanced partner management services and rescreening.

Adolescent↗
PubMed2002

Chlamydia and gonorrhea screening in San Francisco high schools.

BACKGROUND: Previous school-based studies in cities with a high prevalence of chlamydia found a substantial prevalence of chlamydial infection among students. GOAL: The goal was to determine the feasibility and acceptability of chlamydia and gonorrhea screening in San Francisco high schools. STUDY DESIGN: Sexually transmitted disease (STD) education and screening were conducted at four high schools. Students provided basic demographic information and urine specimens for chlamydia and gonorrhea ligase chain reaction testing. RESULTS: Among 283 asymptomatic females screened, 3.9% had chlamydia and 0.7% had gonorrhea. The prevalence of chlamydia was 1.5% among females <16 years of age and 4.6% among females >or=16 years of age. Only 0.8% of asymptomatic males (3/381) had chlamydia, and none had gonorrhea. CONCLUSION: STD screening was both feasible and acceptable in San Francisco high schools. STD screening in high schools should be prioritized as follows: (1) chlamydia screening over gonorrhea screening, (2) female screening over male screening, and (3) screening of older students (juniors and seniors) over screening of younger students.

Adolescent↗
PubMed2006

The cost-effectiveness of an outreach clinical model in the management and prevention of gonorrhea and chlamydia among Chinese female sex workers in Hong Kong.

BACKGROUND: Social marginalization and stigmatization in usual medical care setting may refrain female sex workers (FSWs) from seeking usual medical care for sexually transmitted infections in Hong Kong. GOAL: To evaluate the cost-effectiveness of using an outreach approach for treatment and prevention of gonorrhea and chlamydia among FSWs. STUDY DESIGN: A decision tree was designed to simulate the outcomes of 2 alternatives: (1) outreach service providing treatment of gonorrhea and chlamydia and counseling to FSWs (outreach arm) and (2) no outreach service (control arm). Five tiers of outcomes were estimated for each study arm: (1) total direct medical cost, (2) number of FSWs infected with gonorrhea, (3) number of new cases of gonorrhea in clients transmitted by FSWs, (4) number of FSWs infected with chlamydia, and (5) number of new cases of chlamydia in clients transmitted by FSWs. Clinical inputs were estimated from literature, and cost analysis was conducted from the perspective of a public health organization. RESULTS: Compared to the control group, the marginal savings per new case of infection averted (marginal cost divided by marginal cases of infection) of the outreach group were $10,988 (US dollars) per case of gonorrhea averted in FSWs, $685 per case of gonorrhea averted in clients, $9643 per case of chlamydia averted in FSWs, and $220 per case of chlamydia averted in clients ($1=7.8 Hong Kong dollars). CONCLUSIONS: An outreach clinic is potentially less costly and more effective in preventing transmission of gonorrhea and chlamydia between FSWs and their clients in Hong Kong.

Chlamydia Infections↗
PubMed1990

[Studies on Chlamydia pneumoniae, strain TWAR infection. 2. Seroepidemiology of TWAR on healthy controls and patients with acute respiratory infections].

To determine of Chlamydia pneumoniae, TWAR infection is common in Japan. The author performed a spot antibody prevalence study of adults and children living in Okayama prefecture. This study was carried out by microplate immunofluorescence antibody technique (MFA) using in situ inclusions of Chlamydia pneumoniae (TW-183), Chlamydia trachomatis (L2) and Chlamydia psittaci (Cal 10) as antigens respectively. And each chlamydial antiserum IgG, IgA, IgM titers were determined by the dilution and point for specific staining of the inclusions. The author studied people with and without evidence of acute respiratory infections, as determined by physical examination and medical history. 2050 sera of 1477 cases were collected from both groups between 1987 and 1989. The criteria for judgement the positivity of antibodies to chlamydia species are as follows: By comparing the IgG antibody titers determined with different chlamydia antigen, a case was regarded as having an antibody specific to a particular chlamydia species when the titer was highest for that strain and the titer was greater than x 64. In cases which blood was collected more than once, the point in time at which IgG showed the highest titer was used. TWAR specific antibody was detected to be 52/143 cases (36.4%) of healthy children (age 0-15) and 319/531 cases (60.1%) of healthy adults (age 16-85). It was also detected to be 134/478 cases (27.9%) of child patients with acute respiratory infections (age 0-15), and 231/325 cases (71.1%) of adult patients (age 16-95).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed2004

Differential regulation of inflammatory cytokine secretion by human dendritic cells upon Chlamydia trachomatis infection.

Chlamydia trachomatis is an obligate intracellular gram-negative bacterium responsible for a wide spectrum of diseases in humans. Both genital and ocular C. trachomatis infections are associated with tissue inflammation and pathology. Dendritic cells (DC) play an important role in both innate and adaptive immune responses to microbial pathogens and are a source of inflammatory cytokines. To determine the potential contribution of DC to the inflammatory process, human DC were infected with C. trachomatis serovar E or L2. Both C. trachomatis serovars were found to infect and replicate in DC. Upon infection, DC up-regulated the expression of costimulatory (B7-1) and cell adhesion (ICAM-1) molecules. Furthermore, chlamydial infection induced the secretion of interleukin-1beta (IL-1beta), IL-6, IL-8, IL-12p70, IL-18, and tumor necrosis factor alpha (TNF-alpha). The mechanisms involved in Chlamydia-induced IL-1beta and IL-18 secretion differed from those of the other cytokines. Chlamydia-induced IL-1beta and IL-18 secretion required infection with viable bacteria and was associated with the Chlamydia-induced activation of caspase-1 in infected host cells. In contrast, TNF-alpha and IL-6 secretion did not require that the Chlamydia be viable, suggesting that there are at least two mechanisms involved in the Chlamydia-induced cytokine secretion in DC. Interestingly, an antibody to Toll-like receptor 4 inhibited Chlamydia-induced IL-1beta, IL-6, and TNF-alpha secretion. The data herein demonstrate that DC can be infected by human C. trachomatis serovars and that chlamydial components regulate the secretion of various cytokines in DC. Collectively, these data suggest that DC play a role in the inflammatory processes caused by chlamydial infections.

Caspase 1↗
PubMed2004

Cleavage of host keratin 8 by a Chlamydia-secreted protease.

Chlamydiae have to replicate within a cytoplasmic vacuole in eukaryotic cells. Expansion of the chlamydia-laden vacuole is essential for chlamydial intravacuolar replication, which inevitably causes host cell cytoskeleton rearrangements. A cleavage fragment of keratin 8 corresponding to the central rod region was detected in the soluble fraction of chlamydia-infected cells. Since keratin 8 is a major component of the intermediate filaments in simple epithelial cells, cleavage of keratin 8 may increase the solubility of the host cell cytoskeleton and thus permit vacuole expansion in chlamydia-infected cells. A chlamydia-secreted protease designated CPAF (chlamydial protease/proteasome-like activity factor) was both necessary and sufficient for keratin 8 cleavage in chlamydia-infected cells, suggesting that chlamydiae have evolved specific mechanisms for modifying the host cell cytoskeleton.

Chlamydia↗
PubMed1987

Characterization of the new Chlamydia agent, TWAR, as a unique organism by restriction endonuclease analysis and DNA-DNA hybridization.

Several molecular techniques were used for comparison of the novel Chlamydia agent, TWAR, with Chlamydia trachomatis and Chlamydia psittaci. Unlike all serotypes of C. trachomatis and most strains of C. psittaci, the eight TWAR isolates examined did not contain extrachromosomal DNA. TWAR was readily distinguished from C. trachomatis or C. psittaci by restriction endonuclease analysis, whereas identical or nearly identical restriction patterns were observed among the TWAR isolates. Southern blot analysis with a gene encoding a portion of the C. trachomatis serovar L2 major outer membrane protein as the probe showed that TWAR, like C. psittaci, contained sequences homologous to this gene. However, while the hybridization patterns were identical for all TWAR isolates, they differed from those of any of the other Chlamydia species tested. A PstI gene bank containing TWAR DNA was constructed in pUC19. Random fragments were purified and used for probing Chlamydia chromosomal digests. All of the five probes tested were TWAR specific, with the TWAR isolates showing identical patterns of homology. Qualitative studies of the DNA homology revealed that TWAR did not have significant homology to any of the Chlamydia strains assayed. Collectively, these results demonstrate that the TWAR isolates represent a single strain or closely allied genotypes and are clearly distinct from any of the other chlamydiae tested.

Animals↗
PubMed2002

Accuracy of results obtained by performing a second ligase chain reaction assay and PCR analysis on urine samples with positive or near-cutoff results in the LCx test for Chlamydia trachomatis.

Nucleic acid amplification assays such as the ligase chain reaction and PCR have encountered reproducibility problems. The initial extract and a newly extracted aliquot of urine specimens (n = 120) which had signal-to-cutoff (S/CO) ratios above 0.80 by the LCx Chlamydia assay were retested. Nucleic acid was extracted from an additional urine sample for testing by the AMPLICOR PCR Chlamydia assay. Fifteen percent (18 of 120) of the urine specimens were negative by all repeat tests (initial mean S/CO ratio by the LCx Chlamydia assay, 0.93; S/CO ratio range, 0.80 to 3.30). Repeat testing of the 102 specimens with possible positive results by the LCx Chlamydia assay by use of the initially extracted aliquot confirmed the results for 95 (93.1%) of the specimens; repeat testing of a newly extracted aliquot confirmed the results for 87 (85.3%) of the specimens. Twenty specimens had discordant results by the two repeat LCx Chlamydia assays. A total of 78 of 102 (76.5%) of the specimens were positive by the AMPLICOR PCR, and the AMPLICOR PCR confirmed the results for 82.1% (78 of 95) and 89.6% (78 of 87) of the specimens positive by the two repeat LCx Chlamydia assays, respectively. Some of the discrepancies observed by multiple repeat tests may have been due to specimen mislabeling or contamination during performance of the procedure rather than to the LCx Chlamydia assay. Both assays suffered from a lack of reproducibility on repeat testing with a small proportion of specimens, probably due to the presence of low levels of DNA, the presence of variable amounts of amplification inhibitors, and the loss of DNA during extraction.

Algorithms↗
PubMed2004

Chlamydia trachomatis in the United Kingdom: a systematic review and analysis of prevalence studies.

OBJECTIVES: To undertake a systematic review to obtain estimates of genital Chlamydia trachomatis prevalence in various populations in the United Kingdom and Ireland; to determine which populations have the highest rates of infection; and to explore the most important determinants of infection. METHODS: Electronic databases were searched using the keywords "chlamydia" and "England," "Wales," "UK," "Scotland," "Ireland," or "Britain." Additional unpublished data and references were solicited from experts. Studies were included in the analysis if C trachomatis prevalence was reported, and if they met inclusion criteria. Nine variables identified as potentially important descriptors of chlamydia prevalence were extracted from each study and analysed using various logistic regression models. Only studies reporting prevalence in female populations were included in the models, because there were few data from males. RESULTS: 357 studies were identified using the search methods, 90 of which met inclusion criteria, and 19 of which contributed to the final model. The most influential variables on prevalence were age and setting of the population tested. In general practice surgeries, the under 20 year old age group had an estimated prevalence of 8.1% (95% CI 6.5 to 9.9), 20-24 year olds 5.2% (95% CI 4.3 to 6.3), 25-29 year olds 2.6% (95% CI 2.0 to 3.3), decreasing to 1.4% (95% CI 1.0 to 1.9) in those aged over 30 years. Overall, healthcare settings had higher prevalence estimates than population based studies. For example, among under 20 year olds, estimates were 17.3% (95% CI 13.6 to 21.8) in genitourinary medicine clinics, 12.6% (95% CI 6.4 to 23.2) in antenatal clinics, 12.3% (95% CI 9.8 to 15.3) in termination of pregnancy clinics, 10.7% (95% CI 8.3 to 13.8) in youth clinics, 10.0% (95% CI 8.7 to 11.5) in family planning clinics, and 8.1% (95% CI 6.5 to 9.9) in general practice, compared to 5.0% (95% CI 3.2 to 7.6) in population based studies. The type of test, specimen used, date, and location of test were not strongly associated with chlamydia prevalence. CONCLUSION: The chlamydia prevalence estimates by age and setting from the model may be used to inform chlamydia screening strategies. The systematic review revealed much heterogeneity in the studies identified, but with clear patterns of prevalence. It also indicated gaps in the knowledge about chlamydia prevalence in certain subgroups such as men and the general population.

Adolescent↗
PubMed1989

Detecting Chlamydia trachomatis in men with urethritis: serology v isolation in cell culture.

The accuracy of single serovar (L2) inclusion immunoperoxidase assay (IPA) to show serum IgG and IgA antibodies specific to chlamydiae was compared with culture for Chlamydia trachomatis to diagnose chlamydial infection in 73 men with acute urethritis. C trachomatis only was isolated from 18 (25%), Neisseria gonorrhoeae only from 17 (23%), and both organisms from six (8%). Thus 24 (33%) yielded chlamydiae. Assays based on IgG antibodies to chlamydiae at a titre of 1/64 or more showed high sensitivity (96%) and a good negative predictive value (80%), but low specificity (13%) and agreement (48%) compared with culture. IgG antibodies to chlamydiae at a titre of 1/128 or more showed lower sensitivity (75%) but higher specificity (72%), negative predictive value (79%), and agreement (73%). IgA antibodies to chlamydiae at a titre of 1/8 or more showed a sensitivity of 88%, specificity of 72%, negative predictive value of 88%, and agreement of 79%. An appreciable (fourfold or more) decrease in IgA and IgG titres was observed in most (10) of the 15 men from whom second blood samples were obtained one to two years after treatment. Measuring specific IgA and IgG antibodies to chlamydiae by IPA may serve as a useful complementary test for diagnosing and following up patients with urethritis.

Adolescent↗
PubMed2000

Sociodemography of genital Chlamydia trachomatis in Coventry, UK, 1992-6.

OBJECTIVE: To describe the sociodemographic and geographic risk factors for incident Chlamydia trachomatis genital infection. DESIGN: Cross sectional retrospective study of cases diagnosed in local genitourinary clinics. SETTING: Coventry, West Midlands, from 1992 to 1996. SUBJECTS: 582 female and 620 male Coventry residents aged 15-64 years diagnosed with one or more episodes of genital Chlamydia trachomatis infection by enzyme immunoassay. Subjects were assigned a Townsend deprivation score based on residence. The denominator population aged 15-64 years was derived from 1991 census data. RESULTS: The mean annual incidence of genital chlamydia was 151 episodes (95% CI 140-163) per 100,000 population in men and 138 episodes (95% CI 128-149) per 100,000 population in women. Highest subgroup incidence was observed in 15-19 year old black women (2367 (95% CI 1370-4560) per 100,000), and 20-24 year old black men (1951 (95% CI 1158-3220) per 100,000). In univariate analyses, the most important risk factor for chlamydia infection in males was being black (incidence 1377 (95% CI 1137-1652) per 100,000 for black v 133 (95% CI 122-145) per 100,000 for white; RR 10.4, p < 0.0001) and for women was young age (incidence 475 (95% CI 415-540) per 100,000 for age group 15-19 years v 52 (95% CI 45-60) per 100,000 for age group 25-64 years; RR 9.1, p < 0.0001). In Poisson regression models of first episodes of genital chlamydia, for both males and females the effect of ethnic group could not be fully explained by socioeconomic confounding. There were significant interactions between age and ethnic group for both sexes and between age and level of deprivation for men. Geographical analysis revealed a high incidence of genital chlamydia in estates on the edge of the city as well as the urban core. CONCLUSIONS: There is a complex interaction between geographical location, age, ethnic group, and social deprivation on the risk of acquiring genital Chlamydia trachomatis in Coventry. Better population based data are needed.

Adolescent↗
PubMed2001

Predictors of repeat Chlamydia trachomatis infections diagnosed by DNA amplification testing among inner city females.

OBJECTIVE: To describe the epidemiology of prevalent and incident chlamydia infection in order to assess the appropriate interval for chlamydia screening; and to identify risk factors predictive of infection and repeat infections. DESIGN: Prospective longitudinal study of a consecutive sample of 3860 sexually active females aged 12-60 years tested for C. trachomatis by polymerase chain reaction in Baltimore City clinics during 11,904 patient visits over a 33 month period. RESULTS: Chlamydia prevalence, incidence, and frequency to diagnosis of infection varied by age. Among 2073 females < 25 years, chlamydia infection was found in 31.2%. The median times to first and repeat incident infections were 7.0 months and 7.6 months, respectively. Among 1787 females > or = 25 years, chlamydia infection was found in 9.6%. Median times to first and repeat incident infections were 13.8 months and 11.0 months, respectively. Age < 25 years yielded the highest risk of infection. CONCLUSIONS: Since a high burden of chlamydia was found among mostly asymptomatic females < 25 years in a spectrum of clinical settings, we recommend chlamydia screening for all sexually active females < 25 years at least twice yearly.

Adolescent↗
PubMed1997

Secretion of proinflammatory cytokines by epithelial cells in response to Chlamydia infection suggests a central role for epithelial cells in chlamydial pathogenesis.

Chlamydia species infect epithelial cells at mucosal surfaces, and are major causes of sexually transmitted diseases. Infection is characterized by inflammation which is exacerbated upon reinfection, ultimately leading to tissue damage and scarring. Although central for the development of disease manifestations, little is known about the mechanisms that initiate and sustain the inflammatory response to Chlamydia. Infection of cervical and colonic epithelial cells with Chlamydia trachomatis and Chlamydia psittaci is shown in the present studies to upregulate mRNA expression and secretion of the proinflammatory cytokines IL-8, GRO alpha, GM-CSF, and IL-6. In contrast to the rapid, but transient, cytokine induction following infection with other invasive bacteria, the epithelial cytokine response to Chlamydia was delayed until 20-24 h after infection, persisted throughout the chlamydial growth cycle (2-4 d), and required bacterial protein synthesis. Moreover, epithelial cell lines and primary endocervical epithelial cells released IL-1alpha after Chlamydia infection, and increased secretion of the proinflammatory cytokines could be inhibited by anti-IL-1alpha. This suggests that IL-1alpha, released following lysis of infected epithelial cells, may amplify the inflammatory response by stimulating additional cytokine production by noninfected neighboring cells. These findings suggest a novel pathophysiologic concept wherein the acute host response to Chlamydia at mucosal surfaces is primarily initiated and sustained by epithelial cells, the first and major targets of chlamydial infection.

Actins↗
PubMed2004

Use of HLA-B27 tetramers to identify low-frequency antigen-specific T cells in Chlamydia-triggered reactive arthritis.

Reports of the use of HLA-B27/peptide tetrameric complexes to study peptide-specific CD8+ T cells in HLA-B27+-related diseases are rare. To establish HLA-B27 tetramers we first compared the function of HLA-B27 tetramers with HLA-A2 tetramers by using viral epitopes. HLA-B27 and HLA-A2 tetramers loaded with immunodominant peptides from Epstein-Barr virus were generated with comparable yields and both molecules detected antigen-specific CD8+ T cells. The application of HLA-B27 tetramers in HLA-B27-related diseases was performed with nine recently described Chlamydia-derived peptides in synovial fluid and peripheral blood, to examine the CD8+ T cell response against Chlamydia trachomatis antigens in nine patients with Chlamydia-triggered reactive arthritis (Ct-ReA). Four of six HLA-B27+ Ct-ReA patients had specific synovial T cell binding to at least one HLA-B27/Chlamydia peptide tetramer. The HLA-B27/Chlamydia peptide 195 tetramer bound to synovial T cells from three of six patients and HLA-B27/Chlamydia peptide 133 tetramer to synovial T cells from two patients. However, the frequency of these cells was low (0.02-0.09%). Moreover, we demonstrate two methods to generate HLA-B27-restricted T cell lines. First, HLA-B27 tetramers and magnetic beads were used to sort antigen-specific CD8+ T cells. Second, Chlamydia-infected dendritic cells were used to stimulate CD8+ T cells ex vivo. Highly pure CD8 T cell lines could be generated ex vivo by magnetic sorting by using HLA-B27 tetramers loaded with an EBV peptide. The frequency of Chlamydia-specific, HLA-B27 tetramer-binding CD8+ T cells could be increased by stimulating CD8+ T cells ex vivo with Chlamydia-infected dendritic cells. We conclude that HLA-B27 tetramers are a useful tool for the detection and expansion of HLA-B27-restricted CD8+ T cells. T cells specific for one or more of three Chlamydia-derived peptides were found at low frequency in synovial fluid from HLA-B27+ patients with Ct-ReA. These cells can be expanded ex vivo, suggesting that they are immunologically functional.

Arthritis, Reactive↗
PubMed2003

Co-infection with gonorrhoea and chlamydia: how much is there and what does it mean?

A cross-sectional study of new clients with either gonorrhoea or chlamydia attending King's College Hospital in 1998. One thousand two hundred and thirty-nine women and 1141 men had gonorrhoea, chlamydia or both. Overall, 24.2% (124/512) of heterosexual men and 38.5% (136/353) of women with gonorrhoea also had chlamydia (P<0.001). Of heterosexual males 18.8% (124/660) and 13% (136/1022) of females with chlamydia also had gonorrhoea (P=0.002). Ethnicity had no effect on the proportion of co-infection after controlling for age and gender. Clients with dual infection were younger than those with either infection alone (P=0.0001). Over half of women and a quarter of men aged 15 to 19 years were dually infected so testing for both gonorrhoea and chlamydia may be appropriate in this age group in settings outside genitourinary clinics. The high proportion of cases of gonorrhoea that also have chlamydia justifies the policy of epidemiological treatment for chlamydia.

Adolescent↗