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PubMed2001

The effect of an anti-HLA-B27 immune response on CTL recognition of Chlamydia.

The interplay between triggering bacteria and HLA-B27 in the pathogenesis of the spondyloarthropathies remains one of the most active areas of investigation in the rheumatic diseases. This has proved difficult to study systematically in the clinical setting, and in this study we utilized a rat model to address the influence that B27-related immunity may have on the process of generating anti-Chlamydia immunity. When splenocytes from HLA-B27 DNA-immunized Lewis (LEW) animals received restimulation in vitro with Chlamydia-treated cells from B27-transgenic LEW rats, we observed that in addition to the expected CTL recognition of HLA-B27, there was also anti-Chlamydia CTL killing of Chlamydia-sensitized syngeneic fibroblast targets. This was not seen when responding cells in vitro were naive LEW splenocytes. To confirm the existence of CTLs recognizing both HLA-B27 and Chlamydia, LEW rats were immunized with B27-transgenic LEW cells, instead of the B27 DNA construct. Splenocytes from the immune rats were restimulated in vitro with Chlamydia-treated B27-transgenic LEW cells. In this instance, the CTLs retained the allele-specific recognition of HLA-B27, as well as recognition of Chlamydia-sensitized syngeneic fibroblasts. Thus, if there is prior expansion of an immune response against HLA-B27, then the resulting splenocytes demonstrate a reduced threshold for generating a primary anti-Chlamydia CTL response. These studies implicate a dynamic interrelationship between recognition of HLA-B27 and Chlamydia trachomatis. The results may have implications for deciphering the cellular basis of Chlamydia-induced reactive arthritis.

Animals↗
PubMed2000

Detection of Chlamydia species-specific serum antibodies by prior adsorption of common genus-specific antibodies.

To establish a method for the detection of Chlamydia species-specific antibodies to the three species of Chlamydia responsible for human disease, the author attempted to remove Chlamydia genus-specific antibodies by prior adsorption with heterologous Chlamydia antigen. The effects of adsorption with heterologous antigen were investigated by the microplate immunofluorescence antibody technique. The Chlamydia genus-specific antibodies in immune animal sera were significantly reduced by prior adsorption with heterologous Chlamydia antigen. Chlamydia pecorum which does not infect humans was found to be useful for the adsorption. A preliminary test using Chlamydia trachomatis-infected human sera showed that this adsorption method with C. pecorum is applicable to the serodiagnosis of human Chlamydia infections.

Adsorption↗
PubMed1993

Identification of Chlamydia pneumoniae-specific protein antigens in immunoblots.

The immunoblot patterns of 248 sera, all examined previously by the microimmunofluorescence test (MIF) for species-specific Chlamydia antibodies, were analyzed. Predominant specific antibody activity was directed to the 54 kDa protein of Chlamydia pneumoniae, which was recognized by 93% of sera positive for Chlamydia pneumoniae by MIF but by only 2% of sera positive for Chlamydia trachomatis and negative for Chlamydia pneumoniae and by 3% of sera negative for both Chlamydia pneumoniae and Chlamydia trachomatis. This antigen appears to be specific for Chlamydia pneumoniae. Other Chlamydia pneumoniae-specific protein antigens were recognized far less frequently. Absorption analysis indicated that the 54 kDa protein is located on the surface of the Chlamydia pneumoniae elementary bodies.

Antigens, Bacterial↗
PubMed2001

[Chlamydia antibody titers in patients with coronary disease: relations to age and clinical stage].

BACKGROUND AND AIM: Atherosclerosis and its clinical sequelae are responsible for the highest death rate in industrialized countries. Seroepidemiological, pathological and immunohistochemical studies have suggested a relation between Chlamydia pneumoniae infection and the development of coronary sclerosis. Aim of this study was to investigate the frequency distribution of Chlamydia pneumoniae antibody titers in patients with different clinical stages of coronary artery disease (CAD) and patients without CAD as well as a possible age dependence of antibody titers within the study groups. For this purpose, 522 consecutive patients of a cardiology ward were investigated, over a period of 10 months, for the presence of Chlamydia pneumoniae antibodies (IgG, IgA, IgM) using specific ELISA's. In general, there was no difference in the frequency of positive Chlamydia antibody titers between CAD patients and the control group. Only in the subgroup of unstable CAD-patients < 50 years a tendency of increased antibody titers was present. Patients with stable angina, unstable angina, or acute myocardial infarction exhibited no significant differences in the rate of infection between the different age groups (p < 0.117). In contrast, there was a significant increase in positive Chlamydia pneumoniae antibodies with increasing age in the control group (p = 0.002). The relatively high incidence of positive Chlamydia pneumoniae antibody titers in young CAD patients, which is associated with a loss of age-dependent increase of the antibody titers in the CAD group, might indicate a specific role of Chlamydia pneumoniae infections for the manifestation of premature CAD (before the age of 50). Due to the increased rate of Chlamydia pneumoniae infections with increasing age, the determination of Chlamydia pneumoniae antibody titers does not allow reliable conclusions on the infectious pathogenesis of CAD. Furthermore, our unability to demonstrate differences in antibody titers between CAD patients with stable angina, unstable angina, and acute myocardial infarction suggests that acute Chlamydia pneumoniae infections are not responsible for the development of acute coronary syndromes.

Age Factors↗
PubMed2000

The relationship of inflammation in the papanicolaou smear to Chlamydia trachomatis infection in a high-risk population.

Chlamydia trachomatis is a significant etiologic agent responsible for pelvic inflammatory disease leading to tubal infertility. A screening test aimed at identifying women at risk for Chlamydia trachomatis would be of great utility. The Papanicolaou smear is the most widely used screening test in the world. The association of inflammatory cells in the Papanicolaou smear to Chlamydia infection is controversial. We retrospectively examined the Papanicolaou smears of 80 Chlamydia-negative patients with 80 age-matched Chlamydia-positive patients in a high-risk population to see if a significant difference in inflammation was noted between the two groups. We found a statistically significant difference in inflammation scores between the Chlamydia-positive and Chlamydia-negative groups, evidenced by a sensitivity of 83% and a positive predictive value of 65% when using inflammation on Papanicolaou smears as a marker for Chlamydia infection. Grading of inflammation in the Papanicolaou smear can be of potential use in defining patients at highest risk for Chlamydia in a group considered to be at high risk based on sexual history.

Adult↗
PubMed2004

Testing men who have sex with men for Neisseria gonorrhoeae and Chlamydia trachomatis prior to the introduction of guidelines at an STD clinic in Melbourne.

BACKGROUND: Guidelines for testing men who have sex with men (MSM) were published in 2002. They did not recommend asymptomatic screening for urethral gonorrhoea or pharyngeal screening for chlamydia. To determine if these guidelines were appropriate, we audited gonorrhoea and chlamydia testing of MSM at our Centre. METHODS: We carried out two audits at our Centre between August 2001 and July 2002. The first was an audit of testing MSM for gonorrhoea and/or chlamydia over 12 days. The second was an audit of all positive tests over this 12-month period for gonorrhoea or chlamydia among MSM. RESULTS: During the 12 selected days 89 of 286 men tested (31%) were MSM. Among the MSM testing positive for gonorrhoea and/or chlamydia infection (15, 17%), symptomatic urethral infection was the most common (n = 8). No rectal and pharyngeal infections had site-specific symptoms. Based on the guidelines, 100 of the 334 tests ordered (30%) were not recommended according to the guidelines, and none of these 100 tests yielded a positive result. Over the 12-month audit period, 135 MSM were diagnosed with gonorrhoea and/or chlamydia. For gonorrhoea, site specific symptoms were present in 42 of 43 cases of urethral infection (98%), six of 23 cases of rectal infection (26%), and no cases of pharyngeal infection had symptoms. For chlamydia, site-specific symptoms were present in 29 of 48 cases of urethral infection (60%), six of 33 cases of rectal infection (18%), and in one of the two cases of pharyngeal chlamydia identified. A substantial proportion of cases occurred in clients with HIV infection (21, 16%). CONCLUSIONS: These findings strongly support screening among MSM and in particular not testing asymptomatic MSM for urethral gonorrhoea or any MSM for pharyngeal chlamydia.

Adult↗
PubMed1999

How adequate is adequate for the collection of endocervical specimens for Chlamydia trachomatis testing?

BACKGROUND: Endocervical specimen adequacy has been assessed by subjective criteria that are based on arbitrarily chosen thresholds for the presence of target cells observed on microscopic slide examinations. GOAL OF THIS STUDY: To assess the relationship of chlamydia test positivity to specimen adequacy with the use of a semi-quantitative cytologic staining method for assessing endocervical specimen collection cellularity. STUDY DESIGN: Endocervical specimens for chlamydia testing (PACE 2, GenProbe, San Diego, CA) and for a slide cytologic examination (n = 3,500) were collected in parallel. A semi-quantitative cytologic examination to determine a specimen adequacy (SA) score was performed for every chlamydia-positive result (n = 163) and approximately every fifth negative result (n = 626). The Chi-square test for linear trends was used to assess the relationship between SA scores and chlamydia positivity. The median SA scores for chlamydia-positive and negative slides were compared. RESULTS: The median SA scores for chlamydia-positive and -negative slides were 27 and 20, respectively (P < 0.001). Chlamydia positivity rates increased with increasing specimen adequacy scores (0-9, 2.7%; 10-19, 15.1%; 20-29, 24.8%; and 30-45, 31.3%; Chi-square for linear trend: P < 0.001). CONCLUSION: These results demonstrate a linear relationship between the numbers of cells observed on an endocervical smear and chlamydia positivity rather than the threshold concept in practice. The semiquantitative cytologic technique offers an objective method for further evaluating specimen adequacy for Chlamydia trachomatis testing.

Cervix Uteri↗
PubMed2001

A nationwide sentinel clinic survey of chlamydia trachomatis infection in Finland.

BACKGROUND: Chlamydia trachomatis has been recognized as a major sexually transmitted infection in North America and Western Europe during the past two decades. The incidence of C trachomatis in Finland has been continuously high throughout the 1990s. OBJECTIVES: As the epidemic of C trachomatis infection continues in Finland, there is a need to obtain up-to-date information on the prevalence and patient profiles in the planning of preventive strategies. METHODS: A nationwide sentinel clinic network consisting of seven sexually transmitted disease (STD) and five general student health clinics was established in 1995. Data were collected during a 3-year period (1995-1997) from 3,686 patients with and 32,230 patients without C trachomatis using a self-administered questionnaire. RESULTS: The prevalence of chlamydia was 8.4% in the STD clinics and 5.3% in the general clinics; 90% of the infections were endemic. The prevalence was highest in the youngest age group (15-19 years; 16% in females, 14% in males). The patients with chlamydia were significantly younger (mean age: men 26.6 years, women 23.7 years) than those without chlamydia. Women with chlamydia used oral contraceptives or intrauterine devices (IUD) significantly more often (59%) than women without chlamydia (42%). A high number of sex partners and a history of previous chlamydia during the preceding 12 months were also risk factors. Men contracted chlamydia frequently from a casual partner (61%) but rarely from a commercial sex worker (2%). For women, the source partner was most often a regular one (61%). The median time from exposure to attendance was 34 days, and was highest when the source partner was a spouse. One third of the patients could have spread chlamydia to a new partner before the diagnosis. CONCLUSIONS: C trachomatis infection is spread all over Finland, and the risk factors include younger age, high number of sex partners, and use of oral contraceptives or IUDs. Source partner analysis focused attention on the importance of transmission from regular partners, especially in women. The time from transmission to diagnosis was long, and any effort to shorten this period would be an effective preventive strategy.

Adolescent↗
PubMed2005

Chlamydia LPS and MOMP seropositivity are associated with different cytokine profiles in patients with coronary heart disease.

BACKGROUND: Persistent Chlamydia pneumoniae infection within atherosclerotic plaques are possible stimulators of inflammation in atherosclerosis. Why the microbe develops persistency in some individuals is unknown, but experimental studies in cell cultures and animals have demonstrated the levels of gamma interferon (IFNgamma) and interleukin 10 (IL-10) to be of crucial importance. DESIGN: We wanted to evaluate whether Chlamydia seropositivity in patients with coronary heart disease (CHD) (n = 193) was associated with elevated IFNgamma and IL-10. Two methods for detection of Chlamydia antibodies were included as well as analysis of tumour necrosis factor alpha (TNFalpha), soluble vascular cell adhesion molecule 1 (sVCAM-1) and soluble E-selectin for the evaluation of vascular inflammation. RESULTS: We found that patients with IgA antibodies towards Chlamydia lipopolysaccharide (LPS) had elevated levels of IFNgamma (P = 0.048), IL-10 (P = 0.029), TNFalpha (P = 0.009) and sE-selectin (P = 0.045), while Chlamydia LPS IgG seropositivity predicted elevated levels of IL-10 (P = 0.013). Patients with IgA antibodies towards C. pneumoniae major outer membrane protein (MOMP) without simultaneous LPS IgA seropositivity had lower levels of IFNgamma and sVCAM-1 when compared to patients with Chlamydia LPS IgA alone (P = 0.005 for IFNgamma, P = 0.016 for VCAM-1) and patients with combined Chlamydia MOMP and LPS IgA seropositivity (P = 0.046 and P = 0.013, respectively). CONCLUSIONS: In summary, we demonstrated an association between Chlamydia LPS IgA seropositivity and elevated levels of IFNgamma, IL-10, TNFalpha, sVCAM-1 and sE-selectin in CHD patients that might indicate persistent Chlamydia infection and a proinflammatory state. On the other hand, C. pneumoniae MOMP antibodies were not associated with elevated inflammatory markers and might merely be indicative of past infection, possibly with successful microbe clearance.

Adult↗
PubMed2005

Chlamydia trachomatis infection in Sydney women.

BACKGROUND: In Australia, reported rates of Chlamydia trachomatis infection have been rising progressively since the mid-1990s. Opportunistic testing of sexually active young women attending clinical services for other reasons has already been implemented in a number of other countries. AIMS: To help guide chlamydia testing of women, this study aimed to establish factors predictive of chlamydial infection in an Australian clinical setting. METHODS: Women attending a sexual health service in Sydney who tested positive for C. trachomatis by polymerase chain reaction and who did not have any concurrent urogenital infections (n = 170) were compared with chlamydia-negative controls (n = 170). Factors independently associated with chlamydia were determined using logistic regression. RESULTS: Although they were present in only a minority of infected women, symptoms of dysuria [adjusted odds ratio (AOR) = 3.2 (95% CI: 1.2-9.1), P = 0.03] and postcoital bleeding [AOR = 2.7 (95% CI: 1.0-7.1), P < 0.05] were each independently associated with chlamydia. Symptoms of vaginal discharge (P = 0.3), abdominal pain (P = 0.2), or intermenstrual bleeding (P = 0.1) did not help to discriminate between infected and uninfected women. The following factors were independently associated with chlamydia: younger age (P = 0.003); being overseas-born [AOR = 2.3 (95% CI: 1.3-4.0), P = 0.005]; sex with a partner from overseas [AOR = 2.0 (95% CI: 1.3-12.3), P = 0.01]; and sex with a partner known or suspected to be chlamydia-infected [AOR = 7.4 (95% CI: 3.6-15.0), P < 0.001]. CONCLUSIONS: Chlamydia testing is clinically indicated in sexually active young women with dysuria, postcoital bleeding or contact with a suspected chlamydia-infected partner. Consideration should be given to enhanced screening programs for travelling and migrant men and women in Australian cities.

Adult↗
PubMed1995

Gene knockout mice establish a primary protective role for major histocompatibility complex class II-restricted responses in Chlamydia trachomatis genital tract infection.

Mice with disrupted beta 2-microglobulin (beta 2m-/-), I-A (class II-/-), or CD4 (CD4-/-) genes were examined for their capacity to resolve Chlamydia trachomatis genital tract infection. C57BL/6 and beta 2m-/- mice resolved infection similarly and were culture negative by 4 to 5 weeks following infection. Conversely, major histocompatibility complex (MHC) class II-/- mice failed to resolve infection, and CD4-/- mice showed a significant delay (2 weeks). Secondary challenge of C57BL/6, beta 2m-/-, and CD4-/- mice established that acquired protective immunity, which was characterized by an infection of shortened duration and reduced shedding of infectious organisms, developed. Serological analysis of C57BL/6 and beta 2m-/- mice by enzyme-linked immunosorbent assays revealed no striking differences in the immunoglobulin subclass specificity of the anti-Chlamydia response, although some differences were observed in the magnitude of the immunoglobulin G2a (IgG2a) and IgG2b responses. Class II-/- mice produced lower-titered serum anti-Chlamydia antibodies of all isotypes. The serum antibody responses of CD4-/- mice were similar to those of C57BL/6 mice, except that the anti-Chlamydia IgA response was delayed by approximately 3 weeks. Analysis of vaginal washes for Chlamydia-reactive antibodies revealed the presence of IgG2a, IgG2b, and IgA in C57BL/6 and beta 2m-/- mice and primarily of IgA in CD4-/- mice. Vaginal washes from class II-/- mice were consistently antibody negative. Interestingly, the Chlamydia-specific IgA response in the vaginal washes of CD4-/- mice was delayed, but its appearance coincided with decreased shedding of infectious organisms and resolution of infection. Our results demonstrate that MHC class II-restricted T-cell responses are necessary for the development of protective immunity to Chlamydia genital tract infection and that local (vaginal) anti-Chlamydia IgA antibody coincides with the resolution of infection. A substantive role for MHC class I-restricted T-cell responses in protective immunity to Chlamydia genital tract infection was not confirmed.

Animals↗
PubMed1979

Chlamydia trachomatis genital infections.

The prevalence and clinical features of Chlamydia trachomatis infection were studied in men with nongonococcal urethritis (NGU), in their female sexual partners, and in other women. Of 92 patients with NGU, 36 (39%) were chlamydia-positive; although all had symptoms of urethritis, fewer than half had evident discharge. Clinical features of chlamydia-positive and chlamydia-negative NGU were indistinguishable. Most female contacts of chlamydia-positive patients with NGU were infected with C. trachomatis; contacts of chlamydia-negative patients with NGU seldom harboured chlamydia. Inflammatory and erosive changes were equally common in the uterine cervix of chlamydia-positive and chlamydia-negative women, although almost half of infected cases had no clinical signs of infection and no specific symptoms. In such women the present unavailability of sensitive screening techniques is a major obstacle to the effective control of chlamydial infection.

Adult↗
PubMed2000

[Chlamydia infection and peripartum dilated cardiomyopathy in Niger].

Peripartum cardiac failure due to cardiomyopathy is common in sub-saharan Africa. The etiology is unknown. This study was performed in Niger to assess a possible relationship between peripartum cardiomyopathy and Chlamydia. A total of 50 African women presenting peripartum cardiomyopathy underwent testing for infection by Chlamydia pneumoniae, Chlamydia trachomatis, and Chlamydia psittaci. The inclusion criteria were cardiac failure during the last three months of pregnancy or first 6 months postpartum with echocardiographic evidence of dilated cardiomyopathy. Similar testing was carried out in a control group of 25 African women from the same geographical location without cardiac disease. Detection of specific IgG, IgA and IgM antibodies was performed using the microimmunofluorescence technique. The cut-off values were > or = 1/32 for specific IgG antibody and > or = 1/16 for specific IgA and IgM antibody. Statistical comparison of the patient and control groups was achieved using the chi 2 test. For Chlamydia pneumoniae, 48 patients (96 p. 100) versus 20 controls (80 p. 100) controls were positive for IgG antibodies (p < 0.025) and 39 patients (80 p. 100) versus 14 controls (56 p. 100) were positive for IgA antibodies (p < 0.05). No patient or control demonstrated IgM antibodies for Chlamydia pneumoniae. For Chlamydia trachomatis and Chlamydia psittaci, differences in positive rates were not statistically significant. This is the first study demonstrating infection in patients with peripartum cardiomyopathy. The possible role of Chlamydia pneumoniae is discussed.

Adult↗
PubMedDate not supplied

The prevalence of Chlamydia trachomatis infection in pregnant women.

PURPOSE: The aim of our study was to estimate the prevalence of Chlamydia trachomatis infection, the risk factors, the impact of the infection on the course of pregnancy and the condition of neonates born from pregnancies complicated by Chlamydia trachomatis infection. MATERIALS AND METHODS: 558 pregnant women aged 18-42 yrs, between the 4th and 40th week of pregnancy recruited from the Department of Obstetrics and Gynaecology, Medical Academy Lublin, and 10 men, partners of Chlamydia trachomatis infected patients were included in the study. All patients were examined using an immunoenzymatic method (MEIA). The ligase chain reaction (LCR) method was used only in cases of Chlamydia trachomatis detection with the use of MEIA method, in male partners of infected women and in patients with a cervical erosion and with a mucopurulent cervicitis. There were 64 women and 10 men who were examined using the LCR method. RESULTS: Positive results of MEIA test were found in 10 women (1.8% of studied population). Among men, the infection by Chlamydia trachomatis was present in 9 cases (90%). There were no infections with Chlamydia trachomatis in the group of neonates born from infected mothers. CONCLUSIONS: The prevalence of Chlamydia trachomatis infection was 1.8% in the studied group. The factors favourable for an infection are: young, unmarried patients, residents of towns or cities and changes in the cervix such as cervicitis or ectopy. In the cases of pathological pregnancy we should take into account Chlamydia trachomatis infections as a cause of abdominal pain or premature uterine contractions. The test towards Chlamydia trachomatis infection should be performed in pregnant patients to decrease the rate of pregnancy complications.

Adult↗
PubMed2003

Rapid and standardized detection of Chlamydia pneumoniae using LightCycler real-time fluorescence PCR.

In order to meet the need of many microbiological laboratories for a standardized system for detecting Chlamydia pneumoniae in respiratory specimens, a hybridization probe-based LightCycler (Roche Diagnostics, Germany) PCR assay was developed. The assay's analytical sensitivity and specificity were evaluated according to the recommendations of the Centers for Disease Control and Prevention (USA) and Laboratory Centre for Disease Control (Canada). Seventy-four bacterial species other than Chlamydia pneumoniae, including strains of Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pecorum, tested negative. Six of six representative Chlamydia pneumoniae strains tested positive. An analytical sensitivity of 1 inclusion forming unit per ml of bronchoalveolar lavage fluid, corresponding to 0.02 inclusion forming units per PCR reaction, was observed. The assay showed 100% specificity and sensitivity for Chlamydia pneumoniae when testing DNA preparations from 12 specimens of patients with known pulmonary Chlamydia pneumoniae infection and from 78 specimens of patients with respiratory tract disease of other origin. The newly developed LightCycler assay may contribute to the urgently needed standardization of laboratory diagnosis of Chlamydia pneumoniae.

Bacteriological Techniques↗
PubMed2001

Barriers to screening sexually active adolescent women for chlamydia: a survey of primary care physicians.

PURPOSE: To determine the proportion of primary care physicians who screen sexually active teenage women for chlamydia and to determine demographic factors, practice characteristics, and attitudes associated with chlamydia screening. METHODS: We obtained a random sample of 1600 Pennsylvania physicians from the American Medical Association masterfile, stratified to include at least 40% women and equal numbers of family physicians, internists, obstetricians/gynecologists, and pediatricians. In January 1998, physicians received mailed questionnaires; nonrespondents received two follow-up mailings. Physician characteristics associated with chlamydia screening were determined using bivariate and logistic regression analyses. RESULTS: Only one-third of physicians responded that they would screen asymptomatic, sexually active teenage women for chlamydia during a routine gynecologic examination. In multivariate analysis, physicians were significantly (p <.05) more likely to screen if they were female (43% vs. 24%), worked in a clinic versus solo practice (60% vs. 18%), worked in a metropolitan location (46% vs. 26%), or had a patient population > or = 20% African-American (54% vs. 25%). Attitudes associated with screening included the belief that most 18-year-old women in their practice were sexually active (36% vs. 12%), feeling responsible for providing information about the prevention of sexually transmitted diseases to their patients (42% vs. 21%), or knowing that screening for chlamydia prevents pelvic inflammatory disease (37% vs. 13%). Physicians were less likely to screen if they believed that the prevalence of chlamydia was low (10% vs. 41%). CONCLUSIONS: A majority of physicians do not adhere to recommended chlamydia screening practices for teenage women. Interventions to improve chlamydia screening might target physicians who are male, in private practice, or who practice in rural areas, and should focus on increasing awareness of the prevalence of chlamydia and benefits of screening.

Adolescent↗
PubMed2000

T lymphocyte lines isolated from atheromatous plaque contain cells capable of responding to Chlamydia antigens.

Chlamydia pneumoniae infection is associated with atherosclerosis and the organism has been identified in arterial lesions. To determine whether T lymphocyte-mediated immune responses to Chlamydia antigens within plaque could contribute to pathogenesis, we have derived T cell lines from atherosclerotic plaques of 32 patients. Culture with IL-2 alone proved insufficient for cellular activation and expansion, but additional stimulation with phytohaemagglutinin (PHA) or recall antigens allowed consistent establishment of T cell lines. Furthermore, in cultures of approx. 500 tissue fragments, Chlamydia organisms proved as effective as other recall antigens in producing outgrowth of arterial T cells (20-25% wells produced T cell lines). Testing the antigen responsiveness of T cell lines showed that those derived using Chlamydia organisms were more likely to respond to Chlamydia (5/29+) than those isolated using other stimuli (6/69+ for PHA; 5/57+ for PPD and tetanus toxoid (TT)). However, lines responsive to each of the recall antigens were observed. Using recombinant Chlamydia antigens, some Chlamydia-specific T cell lines were shown to respond to OMP2 and/or hsp60. Those recognizing Chlamydia hsp60 did not cross-react with human hsp60, but human hsp60-responsive lines were also observed. Thus, atherosclerotic plaque tissue contains a variety of memory T lymphocytes, and amongst these are cells capable of recognizing Chlamydia antigens. In a C. pneumoniae-infected plaque, such T cells may be activated by local antigen and could contribute to the inflammatory process in the arterial wall through CD40 ligand expression and cytokine secretion.

Aged↗
PubMed2006

Is there a correlation between vaginal chlamydia infection and cervical smear abnormalities? A community-based study in the Al-Ain district, United Arab Emirates.

AIM: The purpose of this study was to determine the correlation between vaginal chlamydia infection and cervical abnormalities. The data on the prevalence of chlamydia infection and cervical abnormalities have been presented elsewhere and in this article we provide the results of a correlation analysis. METHODS: In this cross-sectional, community-based survey, women attending primary and secondary care in the Al-Ain medical district, United Arab Emirates, were offered cervical screening using the Papanicolaou smear, and chlamydia testing. A total of 793 women underwent cervical screening and 728 were tested for chlamydia. A commercially available kit was used to determine the prevalence of chlamydia. The correlation between cervical abnormalities and chlamydia infection was tested using the chi-squared test or Fisher's exact test, as appropriate. RESULTS: The prevalence of abnormal smears was 1.51% (95% confidence interval [CI], 0.66-2.4). Twelve subjects had abnormal smears, including smears showing atypical squamous cells of undetermined significance. The prevalence of chlamydia infection in this population was 2.5% (95% CI, 1.2-3.3). Statistical analysis showed no association (chi2 0.6, P = 0.4) between the prevalence of chlamydia infection and cervical abnormalities. CONCLUSION: Although there have been earlier reports of an association between vaginal chlamydia and cervical abnormalities, our study does not provide evidence to support this association.

Adolescent↗