Serum IgG and IgA antibodies specific for Chlamydia trachomatis in salpingitis patients as determined by the immunoperoxidase assay

In silico design and analysis of a multiepitope vaccine against Chlamydia

Chlamydia trachomatis (Ct) is the most common sexually transmitted bacterial infection worldwide, potentially leading to severe pathologies including pelvic inflammatory disease, ectopic pregnancy, and tubal infertility if left untreated. Current strategies, including screening and antibiotics, have limited effectiveness due to high rates of asymptomatic cases and logistical challenges. A multiepitope prophylactic vaccine could afford long-term protection against infection. Immunoinformatic analyses were employed to design a multiepitope Chlamydia vaccine antigen. B- and T-cell epitopes from five highly conserved and immunogenic Ct antigens were predicted and selected for the vaccine design. The final construct, adjuvanted with cholera toxin A1 subunit (CTA1), was further screened for immunogenicity. CTA1-MECA (multiepitope Chlamydia trachomatis antigen) was identified as antigenic and nonallergenic. A tertiary structure was predicted, refined, and validated as a good quality model. Molecular docking exhibited strong interactions between the vaccine and toll-like receptor 4 (TLR4). Additionally, immune responses consistent with protection including IFN-γ, IgG + IgM antibodies, and T- and B-cell responses were predicted following vaccination in an immune simulation. Expression of the construct in an Escherichia coli expression vector proved efficient. To further validate the vaccine efficacy, we assessed its immunogenicity in mice. Immunization with CTA1-MECA elicited high levels of Chlamydia-specific antibodies in mucosal and systemic compartments.

Shift work influences the outcomes of Chlamydia infection and pathogenesis

Shift work, performed by approximately 21 million Americans, is irregular or unusual work schedule hours occurring after 6:00 pm. Shift work has been shown to disrupt circadian rhythms and is associated with several adverse health outcomes and chronic diseases such as cancer, gastrointestinal and psychiatric diseases and disorders. It is unclear if shift work influences the complications associated with certain infectious agents, such as pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility resulting from genital chlamydial infection. We used an Environmental circadian disruption (ECD) model mimicking circadian disruption occurring during shift work, where mice had a 6-h advance in the normal light/dark cycle (LD) every week for a month. Control group mice were housed under normal 12/12 LD cycle. Our hypothesis was that compared to controls, mice that had their circadian rhythms disrupted in this ECD model will have a higher Chlamydia load, more pathology and decreased fertility rate following Chlamydia infection. Results showed that, compared to controls, mice that had their circadian rhythms disrupted (ECD) had higher Chlamydia loads, more tissue alterations or lesions, and lower fertility rate associated with chlamydial infection. Also, infected ECD mice elicited higher proinflammatory cytokines compared to mice under normal 12/12 LD cycle. These results imply that there might be an association between shift work and the increased likelihood of developing more severe disease from Chlamydia infection.

The molecular fingerprint of high grade serous ovarian cancer reflects its fallopian tube origin

High grade serous ovarian cancer (HGSC), the most lethal and frequent type of epithelial ovarian cancer (EOC), has poor long term prognosis due to a combination of factors: late detection, great metastatic potential and the capacity to develop resistance to available therapeutic drugs. Furthermore, there has been considerable controversy concerning the etiology of this malignancy. New studies, both clinical and molecular, strongly suggest that HGSC originates not from the surface of the ovary, but from the epithelial layer of the neighboring fallopian tube fimbriae. In this paper we summarize data supporting the central role of fallopian tube epithelium in the development of HGSC. Specifically, we address cellular pathways and regulatory mechanisms which are modulated in the process of transformation, but also genetic changes which accumulate during disease progression. Similarities between fallopian tube mucosa and the malignant tissue of HGSC warrant a closer analysis of homeostatic mechanisms in healthy epithelium in order to elucidate key steps in disease development. Finally, we highlight the importance of the cancer stem cell (CSC) identification and understanding of its niche regulation for improvement of therapeutic strategies.

Detection of Antibodies to Chlamydia trachomatis With Peptide-Based Species-Specific Enzyme Immunoassay

OBJECTIVE

We have evaluated the sensitivity and specificity of a new synthetic peptide-based species-specific enzyme immunoassay (EIA) for detection of Chlamydia trachomatis IgG and IgA antibodies.

METHODS

Synthetic peptides derived from variable domain IV of major outer membrane protein (MOMP) were used as antigen in indirect EIA. IgG and IgA antibodies were measured in parallel with serum samples from C. trachomatis culture positive, culture negative, and antigen positive patients, and women with suspected C. trachomatis infection and blood donors. Sera from children under 15 years of age were used as controls.

RESULTS

Culture positive women, culture positive men, and antigen positive women had positive peptide serology in 84.2%, 61.3%, and 93.1% of the cases, respectively. Among C. trachomatis suspected women, the antibody prevalence was 63.6%. Randomly collected blood donors showed a prevalence of 21.5%. Children with C. pneumoniae antibodies determined with the microimmuno-fluorescence (MIF) method did not show any reactivity in the C. trachomatis peptide EIA.

CONCLUSIONS

The results suggest that the new EIA test is highly specific for C. trachomatis, and C. pneumoniae antibodies do not interfere. Both IgG and IgA antibodies appear within at least 2 weeks in acute phase of infection among both culture positive and culture negative patients.

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.

Increased prevalence of IgA-Chlamydia antibodies in NIDDM patients

Chlamydia trachomatis oculogenital infection is a common disease in western societies. Despite the fact that diabetes is accompanied by increased risk for infections, no data on chlamydial infections in the non-insulin-dependent diabetic (NIDDM) patient exist. In our study Chlamydia antibodies were determined using an immunoperoxidase reaction in NIDDM patients (n = 79) and in a local nondiabetic control population (n = 125) which was randomly invited to a medical control visit without any preselection criteria. In total, 46% of diabetics and 55% of controls were IgG-Chlamydia antibody positive (ns). Using IgA-Chlamydia antibodies to define 'seroactive' chlamydial infection, 22% of NIDDM patients and 14% of controls were positive. Thus seroactive chlamydial infection of all patients with proven contact to Chlamydia (IgG-Chlamydia antibody positive) was 47% in diabetics versus 25% in controls, respectively (P < 0.05). Forming subgroups, significance was reached in females (52% vs. 32%, P < 0.05) only, but a similar trend was observed in males (36% vs. 21%, ns). Seroactivity was neither correlated with HbA1c nor with nephelometrically determined total serum immunoglobulins (IgG, IgA). Additionally we observed significantly elevated total IgM and IgA-levels in NIDDM patients whereas IgG-levels were comparable in both groups. In conclusion, seroactive chlamydial infections in subjects with proven contact to Chlamydia are more frequent in NIDDM patients than in nondiabetic controls. Additionally, higher IgM and IgA serum levels might indicate a higher susceptibility to active surface infections in NIDDM.

Enzyme immunoassay with enhanced specificity for detection of antibodies to Chlamydia trachomatis

Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.

Chlamydial serology in genital infections: ImmunoComb versus Ipazyme

The ImmunoComb Chlamydia trachomatis IgG/IgA (Orgenics, Israel) is a new serologic test using C. trachomatis L2 elementary bodies (Washington Research Foundation, Seattle) as antigen. The Ipazyme IgG/IgA test (Savyon, Israel) employs whole cells with C. trachomatis L2 inclusions, i.e. elementary and reticulate bodies. Theoretically, the ImmunoComb is expected to be less cross-reactive (LPS) with Chlamydia pneumoniae than the Ipazyme (LPS and reticulate body group specific antigens). Compared with the Ipazyme, the ImmunoComb IgA showed both a higher positive predictive value (36% versus 25%) and sensitivity (67% versus 33%) for antigen detection in a control group of 100 post partum women with a 6% prevalence of C. trachomatis positive cervical smears. In sterility patients (45 cases with occluded and 53 with open fallopian tubes) the tube status was predicted by the ImmunoComb (Ipazyme) with 74% (72%) positive predictive value, 87% (80%) sensitivity, and 87% (81%) negative predictive value. IgG/IgA prevalence in 118 patients with C. trachomatis positive cervical smears was 85%/55% for the ImmunoComb and 84%/49% for the Ipazyme. The ImmunoComb is considerably faster and easier in handling and less subjective in reading than the Ipazyme.

Persistence of antichlamydial antibodies after treatment of acute salpingitis with doxycycline

The effect of treatment with doxycycline on serum IgG and IgA antichlamydial antibodies was evaluated in 33 women who had had acute salpingitis associated with high titers of serum IgG (> or = 1:128) and/or IgA (> or = 1:16) antichlamydial antibodies. Overall, 29 women (87.9%) remained with high titers of IgG and/or IgA antibodies. No change or insignificant change in IgG antibody titer was demonstrated in 21 women (63.6%) and in IgA antibody titer in 21 women (63.6%). Positive seroconversion or a significant increase (> or = 4-fold) in IgG antibody titer was demonstrated in eight women (24.2%) and in IgA antibody titer in six women (18.1%). Negative seroconversion or a significant decrease in IgG antibody titer was demonstrated in four women (12.1%) and in IgA antibody titer in six women (18.1%). It is concluded that in most patients who had acute salpingitis associated with pretreatment high titers of serum antichlamydial antibodies, posttreatment titers may remain high even if treatment with doxycycline results in complete resolution of clinical signs and symptoms of the disease.

Male infertility: current concepts

The purpose of the article is to review the current concepts regarding the etiology and treatment of male-factor infertility. The following general conclusions can be drawn: (a) conventional parameters for sperm quality and male fertility are inadequate and any assessment should involve several different tests of sperm cell function to increase the fertility prognosis; (b) the causes of disturbed sperm quality are still poorly understood; (c) the role of the varicocele is still controversial but some of the discrepancies reported in the literature may be explained by the negative influence of other factors such as smoking, epididymal pathology or glandular infections operating either in conjunction or independent of the varicocele; (d) the role of chronic inflammatory processes in the reproductive organs, in particular the involvement of chronic chlamydial infections, has been underestimated, largely because it is often asymptomatic and difficult to demonstrate objectively; (e) partial androgen insensitivity may account for a significant number of cases of severe oligozoospermia; (f) no major advances have been made in the medical treatment of poor sperm quality; (g) assisted fertilization techniques such as IVF and GIFT offer encouraging possibilities for the treatment of male-factor infertility; and (h) recent advances in microsurgical techniques are increasing the treatment possibilities for certain forms of obstructive azoospermia and severe oligozoospermia.

Detection of a local prostatic immune response to bacterial prostatitis

Bacteria-specific antibody responses in expressed prostatic secretions (EPS) were investigated by use of an indirect immunoperoxidase method. Positive responses were observed in all 12 patients with acute bacterial prostatis due to gram-negative rods. However, in 41 patients with chromic prostatitis, antibody responses varied depending on the bacterial species; no positive responses were observed in cases resulting from gram-positive cocci.

The role of Chlamydia trachomatis and Neisseria gonorrhoeae in the aetiology of ectopic pregnancy in Gabon

OBJECTIVE

To study the association between ectopic pregnancy and Chlamydia trachomatis and Neisseria gonorrhoeae.

DESIGN

A prospective observational study with two comparison groups.

SETTING

A general hospital in Franceville, Gabon.

SUBJECTS

Forty-five women with ectopic pregnancies and two comparison groups each of 45 women, one at 5 to 12 and the other at 32 to 41 weeks gestation.

MAIN OUTCOME MEASURES

Serum levels of IgG and IgA antibodies to C. trachomatis (L1 and rMOMP) and N. gonorrhoeae (pili) in all the women. In the women with ectopic pregnancy peritoneal adhesions were scored and in 40 women samples of tube were cultured for organisms being studied.

RESULTS

IgG and IgA antibodies to C. trachomatis (L1) were detected in 84% of the ectopic group and 53 and 39% of the comparison groups (P less than 0.0001). IgG and IgA antibodies to N. gonorrhoeae occurred in 49, 28 and 18% and 49, 28 and 26% of the groups but the differences were not statistically significant. Adhesions were positively associated with the antibodies. C. trachomatis was cultured from the tubes of 71% of the women with ectopic pregnancy.

CONCLUSIONS

Infection with chlamydia, and probably with N. gonorrhoeae, is an important factor in the causation of ectopic pregnancy in Gabon.

Chlamydial IgG and IgA in serum and follicular fluid among patients undergoing in vitro fertilisation

The point prevalence of IgG and IgA antibodies to Chlamydia was analyzed in serum and follicular fluid in 63 patients undergoing in vitro fertilisation (IVF) in comparison to sera of 298 healthy women by the single serovar (L2) inclusion immunoperoxidase assay (IPA). The presence of specific IgG and IgA to Chlamydia in follicular fluid was demonstrated. No statistical association was found between the presence of specific Chlamydia IgG and IgA in serum and follicular fluid to oocyte fertilization. The positive predictive value for mechanical infertility of Chlamydia IgG at titers of greater than or equal to 128 and IgA titers at greater than or equal to 16 was 91 and 92%, respectively, in this high-risk group for mechanical infertility. Multiple regression analysis singled out Chlamydia IgG levels as a major contributor to the variance between the groups of infertile patients.

Laboratory survey of Chlamydia trachomatis ocular infections

The authors used immunofluorescence and immunoperoxidase tests to study a group of 101 patients with acute or chronic conjunctivitis, etiologically unrelated to conventional bacterial pathogens, and a control group of 30 healthy adults. Positive titers of IgG in serum and of IgA in lacrimal secretions against Chlamydia, detected by IPA, correlated with the identification of microorganisms by direct immunofluorescence. The use of both tests allows a precise evaluation of the stage of the infection and of its evolutive pattern.

Vaginal and cervical pH in normal pregnancy and pregnancy complicated by preterm labor

A prospective study was performed in order to determine vaginal and cervical pH in pregnancy. In normal pregnancy vaginal pH (using a pH meter with connected glass electrode) was found to be between 3.8 and 4.0 (1 SD +/- 0.3) at the introitus, mid-vaginal, and at the anterior and posterior fornix. In patients with preterm labor (n = 50) or prolonged rupture of the membranes (PROM, n = 35) pH was increased significantly to 4.2-4.5 (1 SD +/- 0.7) resp. to 5.2-6.1 (1 SD +/- 0.8). Cervical pH ranges between 6.5 and 7.0 in all groups studied. Elevated pH values are due to disturbed vaginal flora. We recommend vaginal pH measurement for an quick detection of infection in cases with preterm labor and for clarifying PROM in suspicious cases.

The association between chlamydial-specific IgG and IgA antibodies and pregnancy outcome in an in vitro fertilization program

Chlamydial-specific IgG and IgA antibodies were determined by a single serovar (L2) immunoperoxidase assay (IPA) in the serum of all patients that have conceived in an in vitro fertilization and embryo transfer (IVF & ET) program (n = 106) and in a group of patients that went through the program at the same period of time and did not conceive (n = 94). The prevalence rate of elevated IPA IgG (titers greater than or equal to 1:128) and IPA IgA (titers greater than or equal to 1:16) specific to chlamydiae was significantly higher (P less than 0.001) in the IVF & ET pregnancy loss and nonconception groups ("failures") versus the IVF & ET term pregnancy group ("successes") (74 vs 47%, odds ratio = 4.1, and 34 vs 14%, odds ratio = 4.3, respectively). Stepwise discriminant analysis revealed that elevated specific chlamydial IgG had the greatest effect on the variance between successes and failures in this study group. Our study indicates the possible role of past or chronic active chlamydiae infection on the "take-home baby rate" in an IVF & ET program.

Serum IgG and IgA antibodies to Chlamydia in ectopic pregnancies

The possible association of Chlamydia trachomatis with ectopic pregnancies was evaluated in a case-control study, comprising 35 women with ectopic pregnancy and 294 apparently healthy women who served as controls. Chlamydia-specific IgG and IgA antibodies were determined by single serovar (L2) inclusion immunoperoxidase assay (IPA). Socio-demographic characteristics, gynecological history and contraceptive methods were also evaluated. An inverse relationship was found between the educational levels and the prevalence of IgG and IgA antibodies to chlamydia. The prevalence rate of elevated IPA IgG (titer greater than or equal to 128) and IPA IgA (titer greater than or equal to 16) specific to chlamydia was significantly higher in women with ectopic pregnancy versus controls (32% vs 8%, respectively, for IgG: odds ratio = 4.9; and 26% vs 4% for IgA: odds ratio = 7.5). Chlamydia trachomatis was not isolated in cell cultures in 10 specimens available from fallopian tubes of women with ectopic pregnancy. Only 9% of the women recall having pelvic inflammatory disease (PID) indicating that most of the infections were asymptomatic. Women who did not use IUD had a higher proportion of chlamydia-specific IgG and IgA seropositives, though not statistically significant, as compared to IUD users. This study further supports the hypothesis that subclinical infection of the tube with C. trachomatis may underlie ectopic pregnancies.

Laboratory diagnosis of human chlamydial infections

Chlamydia trachomatis is a human pathogen that causes ocular disease (trachoma and inclusion conjunctivitis), genital disease (cervicitis, urethritis, salpingitis, and lymphogranuloma venereum), and respiratory disease (infant pneumonitis). Respiratory chlamydioses also occur with infection by avian strains of C. psittaci or infection by the newly described TWAR agent. Diagnosis of most acute C. trachomatis infections relies on detection of the infecting agent by cell culture, fluorescent antibody, immunoassay, cytopathologic, or nucleic acid hybridization methods. Individual non-culture tests for C. trachomatis are less sensitive and specific than the best chlamydial cell culture system but offer the advantages of reduced technology and simple transport of clinical specimens. Currently available nonculture tests for C. trachomatis perform adequately as screening tests in populations in which the prevalence of infection is greater than 10%. A negative culture or nonculture test for C. trachomatis does not, however, exclude infection. The predictive value of a positive nonculture test may be unsatisfactory when populations of low infection prevalence are tested. Tests that detect antibody responses to chlamydial infection have limited utility in diagnosis of acute chlamydial infection because of the high prevalence of persistent antibody in healthy adults and the cross-reactivity due to infection by the highly prevalent C. trachomatis and TWAR agents. Assays for changes in antibody titer to the chlamydial genus antigen are used for the diagnosis of respiratory chlamydioses. A single serum sample that is negative for chlamydial antibody excludes the diagnosis of lymphogranuloma venereum.

Chlamydia specific IgG and IgA antibodies in women with obstructive infertility as determined by immunoblotting and immunoperoxidase assays

The prevalence rate of IgG and IgA antibodies to Chlamydia was analyzed in 50 women with laparoscopy-verified tubal infertility and in 50 age-matched control women by single serovar (L2) inclusion immunoperoxidase assay (IPA) and by immunoblotting technique (IB). Women with tubal infertility had significantly (p less than 0.001) elevated IPA Chlamydia IgG antibody titer greater than or equal to 128 and greater than or equal to 256 than controls (64% vs 16%. Odds ratios = 9.3 and 50% vs 10%, Odds ratio = 9 respectively). The prevalence rate of IPA IgA antibody titer (greater than or equal to 16) to Chlamydia was also significantly higher (p less than 0.001) in women with tubal infertility than controls (48% vs 8%, Odds ratio = 10.6). Antibodies to at least 19 chlamydial structural polypeptides ranging in molecular weight from 30 kD to 204 kD, were detected by the IB technique in the IPA seropositive sera. Antibodies to 57-60 kD were detectable in almost all the IPA IgG and IgA seropositive sera. The prevalence rate of IgG antibody to 57 kD-60 kD was significantly higher in women with obstructive infertility than healthy woman (84% vs. 56% p less than 0.01; Odds ratio = 3.8). More significantly, higher differences to 57-60 kD polypeptide were found in the case of IgA between the infertile women and controls (52% vs. 10%, p less than 0.001; Odds ratio = 9.7). The significance of IPA and IB technique for screening of infertile women is discussed.

Diagnosis of Chlamydia trachomatis infection--culture versus serology

The diagnostic value of different laboratory methods in detecting Chlamydia trachomatis infections in high risk groups was analysed. The efficiency of a direct specimen test was compared with serology (IgG and IgM ELISA) and culture in L929 cells, stained either with fluorescein conjugated monoclonal antibodies or with iodine. Patients (no. = 1041) with localized genital infections attending a STD clinic, sexual contacts and patients with ascending infections from urological and gynecological clinics were examined. Chlamydia trachomatis was detected in 225 patients: 210 (93.3%) were reactive in the direct test (smears stained with monoclonal antibodies), whereas culture missed only 5 (sensitivity 97.8%) when stained by the same method. Cultures stained with iodine produced the lowest recovery rate (73.8%), but this rate increased to 80.9% when a second passage was performed. In addition the prevalence of Neisseria gonorrhoeae, Mycoplasma hominis, Ureaplasma urealyticum, Candida albicans and Trichomonas vaginalis was investigated. In patients with non-gonococcal urethritis (no. = 331) and cervicitis (no. = 353), Chlamydia trachomatis was isolated in 32.3% and 12.8% respectively. However, this pathogen could be isolated in only 3 (15.8%) out of 19 patients with epididymitis and 15 (14%) out of 107 patients with adnexitis, although 66.7% and 93.3% respectively had specific IgG antibodies. Specific IgM could by detected with a sandwich ELISA in patients with adnexitis (46.7%), epididymitis (33.3%), cervicitis (22.2%), non-gonococcal urethritis (14%) and in the sexual partners of patients with genital infections (35.7%). The direct specimen test with monoclonal antibodies is the method of choice for the diagnosis of a C. trachomatis infection in patients with urethritis and cervicitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum-specific antibodies for Chlamydia trachomatis in premature contractions

A case-control study was undertaken to examine the possible morbidity associated with Chlamydia trachomatis in 28 pregnant women having idiopathic premature contractions, in 35 healthy preterm pregnant women, and in 43 healthy pregnant women at term. Serum C. trachomatis IgG- and IgA-specific antibodies were determined by the single serovar inclusion immunoperoxidase assay. There were no significant differences in the prevalence rate of elevated C. trachomatis IgG-specific antibodies (titer greater than or equal to 1:128) between pregnant women suffering from idiopathic premature contractions as compared with healthy preterm and term pregnant women (11%, 28%, and 26%, respectively). The known prevalence rate in a normal healthy population is 23%. The prevalence rate of elevated C. trachomatis IgA-specific antibodies (titer greater than or equal to 1:16) was significantly lower in the pregnant women with idiopathic premature contractions as compared with the healthy preterm and term pregnant women (0%, 20%, and 17%, respectively; p less than 0.002 and p less than 0.012). These findings do not support the assumption that C. trachomatis has a role in premature contractions.

Chlamydia trachomatis serology in ankylosing spondylitis

Demonstration of chlamydial antibodies in patients with ankylosing spondylitis (AS) could show an etiological role of Chlamydia trachomatis in this condition. We studied serum specimens from 50 HLA-B27 positive patients with AS (Group I), 34 HLA-B27 positive patients with other rheumatic diseases (Group II), 67 HLA-B27 positive healthy blood donors (Group III) and 37 healthy untyped blood donors. (Group IV). Measured by an immunoperoxidase assay (IPA) chlamydial IgA (titre greater than or equal to 1:20) was more prevalent in the HLA-B27 positive persons than in the healthy controls not selected for HLA-group (Groups I + II + III vs IV : p less than 0.02). Chlamydia trachomatis IgA-IPA containing sera also had specific IgG-IPA antibodies (greater than or equal to 1:80) in 29 (96%) out of 30 sera from HLA-B27 positive individuals and controls. Conversely, 45% of specific IgG-positive (greater than or equal to 1:80) AS sera, 27.7% sera in Group II, 39.4% Group III sera vs. 11.1% of sera in Group IV had concomitant chlamydial IgA (greater than or equal to 1:20). The differences in the prevalence of specific IgA were statistically significant: Group I vs. IV : p less than 0.01; Group III vs. IV :p less than 0.05 and Gr. I + II + III vs. IV: p less than 0.05. Our data suggest an enhanced antibody production against Chlamydia trachomatis among the HLA-B27 positive individuals whether they have AS or are healthy.

Evaluation of diagnostic tools for adult chlamydial keratoconjunctivitis

Conjunctival smears and serum specimens of 150 patients with presumed chlamydial keratoconjunctivitis were evaluated over a period of 16 months and compared to age- and sex-matched healthy controls. Sensitivity, specificity, and predictive values of fluorescent monoclonal antibody (FMAb) direct tests, IgG single antigen tests for the detection of serum antibody (IgG-IFT), and IgA and IgG immunoperoxidase tests (IgA-IPAs and IgG-IPAs) for serum antibody were compared to McCoy cell culture techniques in a nonoptimized clinical setting. Thus, FMAb sensitivity was 100%, specificity was 52%, and predictive value was 30%. IgG-IFT sensitivity was 94%, specificity was 67%, and predictive value was 37%. IgA-IPA sensitivity was 100%, specificity was 70%, and predictive value was 40%. The IgG-IPA was sensitive but nonspecific. With respect to the current epidemiologic situation in our area, FMAb and IgA-IPA in addition to McCoy cell culture techniques may represent valuable diagnostic tools for the detection of chlamydial disease.