High frequency of latent Chlamydia trachomatis infection in patients with rhegmatogenous retinal detachment.

AIM: To determine the frequency of detection of ocular and extraocular Chlamydia trachomatis (CT) infection in non-high myopes with rhegmatogenous retinal detachment (RRD). METHODS: This was a single-center, nonrandomized, prospective, case-control study. One hundred and four patients were divided into a study group with RRD (n=63) and a control group with traumatic retinal detachment (n=41). Samples of subretinal fluid (SFR), conjunctival, urethral/cervical swabs, and blood were collected. The frequency of detection of CT infection in SRF samples was determined by polymerase chain reaction (PCR), direct fluorescence assay (DFA) and cell culture, whereas that in conjunctival swabs was determined by PCR and DFA, and those in urethral/cervical swabs and blood were determined by DFA. Yates Chi-square test (with Bonferroni correction) and two-tailed Student's t-test were used for statistical analysis. RESULTS: SRF CT infection was detected more frequently in the study group (50.8%-71.4%) than in the control group (9.8%-12.2%) by all the methods used (P<0.01). The frequency of detection of conjunctival CT infection by DFA was higher in the RRD patients compared with the controls (81.0% vs 24.4%, P=0.004). The PCR detected conjunctival CT infection more often in the study group than in the controls (46.0% vs 9.8%, P=0.007). The DFA detected CT in blood specimens almost as frequently as in urogenital specimens, for the RRD patients (61.2% vs 63.5%) and the controls (7.3% vs 9.8%). CONCLUSION: CT infection is detected with high frequency in non-high myopes with RRD.

Latent Infections as a Risk Factor for Posttrabeculectomy Bleb Failure.

PURPOSE: To investigate latent conjunctival Chlamydia trachomatis (CT) and Bacteroides fragilis (BF) infections as potential risk factors for posttrabeculectomy bleb failure. PATIENTS AND METHODS: This retrospective observational study included 50 primary open-angle glaucoma eyes of 50 patients who were submitted to trabeculectomy without cytostatics from September 2010 to June 2011 and were followed up for at least a year. Preoperatively, conjunctival scrapings were taken and their specimens subjected to polymerase chain reaction, direct fluorescent assay and cell culture testing for CT, and culture for BF on blood agar medium. Serum CT-specific IgG and IgA and tear interleukin (IL)-1ß and IL-8 concentrations were measured with enzyme-linked immunosorbent assay. We defined bleb failure as intraocular pressure >21 mm Hg with antiglaucoma medications, resulting from reduced bleb filtration capacity due to bleb fibrosis, fistula obstruction, flattened bleb, or encapsulated bleb, and no earlier than 2 weeks after surgery. At the time of the reintervention, a scleroconjunctival biopsy was obtained for histopathology (including direct fluorescent assay testing for CT). Eyes were divided into a failure group and a nonfailure group, depending on whether they developed bleb failure (required reintervention) or not within a follow-up year. RESULTS: In the failure group (n=18), the frequencies of detection of CT and BF in conjunctival specimens were 27.8% and 66.7%, respectively, versus 0% and 9.4% in the nonfailure group (n=32). CT and BF were detected in 11.1% and 11.1%, respectively, of scleroconjunctival biopsies. IgG and IgA seropositivity to CT was found in 66.7% and 33.3%, respectively, of the failure group patients, versus 9.4% and 0% of the nonfailure group patients. Tear IL-1ß and IL-8 levels were markedly elevated in the failure group (468.83±80.43 and 107.89±15.11 pg/mL, respectively) versus the nonfailure group (22.34±5.43 and 9.34±2.83 pg/mL, respectively). CONCLUSION: Being a contributor to low-grade conjunctival inflammation, latent conjunctival CT, and BF infections in primary open-angle glaucoma patients represent risk factors for posttrabeculectomy bleb failure.

Infection of Human Retinal Pigment Epithelium with Chlamydia trachomatis.

PURPOSE: Little is known about the susceptibility of posterior segment tissues, particularly the human retinal pigment epithelium (hRPE), to Chlamydia trachomatis. The purpose of the study was to investigate the possibility of infecting the hRPE with Chlamydia trachomatis, and to examine the infectivity of different Chlamydia trachomatis clinical isolates for hRPE cells and the hRPE cell response to the infection. METHODS: Cultured hRPE and McCoy cells were inoculated with eight Chlamydia trachomatis (serovar E) clinical isolates at multiplicity of infection (MOI) of 2.0 or 0.3. To detect Chlamydia trachomatis, samples were stained immunohistochemically with anti-major outer membrane protein antibodies at 24h, 48h, and 72h postinoculation (PI). The changes in the expression of signaling molecules and proteins of cytoskeleton and extracellular matrix in hRPE cells were examined immunohistochemically. RESULTS: All eight clinical isolates demonstrated ability to infect hRPE cells. At equal MOI of 0.3, the infectivity of Chlamydia trachomatis clinical isolates for RPE culture was found to be at least as high as that for McCoy cell culture. At 24h PI, the percentage of inclusion-containing cells varied from 1.5 ± 0.52 to 14.6 ± 3.3% in hRPE cell culture infected at MOI of 2.0 against 0.37 ± 0.34 to 8.9 ± 0.2% in McCoy cell culture infected at MOI of 0.3. Collagen type I, collagen type IV, basic fibroblast growth factor, transforming growth factor-beta and interleukin-8 expression at 48h PI were maximally increased, by 2.1-, 1.3-, 1.5-, 1.5- and 1.6-fold, respectively, in the Chlamydia trachomatis-infected compared with control hRPE cell culture specimens (P < 0.05). CONCLUSIONS: This study, for the first time, proved the possibility of infecting hRPE cultured cells with Chlamydia trachomatis, which leads to proproliferative and proinflammatory changes in the expression of signaling molecules and extracellular matrix components.

High Frequency of Latent Conjunctival C. trachomatis, M. hominis, and U. urealyticum Infections in Young Adults with Dry Eye Disease.

Aim. To determine the frequency of detection of conjunctival C. trachomatis (CT), M. hominis (MH), and U. urealyticum (UU) infections in young adults with dry eye disease (DED), since these infections may potentially produce the chronic subclinical inflammation characteristic of DED. Materials and Methods. The study included subjects of 25-45 years of age, divided into the DED (n = 114) and nondry eye control (n = 98) groups, with the diagnosis based on self-reported complaints, biomicroscopy, the Schirmer I test, and break-up time. All patients had conjunctival scrapings taken to detect CT, MH, and UU with direct fluorescent-antibody assay kits. Results. At least one of the three microorganisms was found in 87.7% of the DED patients versus 8.2% of the controls. Of all the DED patients, 63.2%, 50.8%, and 42.1% were found to be infected with CT, MH, and UU, respectively. Multiple pathogens were identified in 65% of the DED patients found to be infected. CT infection was detected in 6.1% of the controls. Conclusion. C. trachomatis, M. hominis, and U. urealyticum were detected with high frequency in the conjunctiva of young adults with DED and may be an important risk factor for DED in them.

Chronic ocular Chlamydia trachomatis infection in rabbits: clinical and histopathological findings in the posterior segment.

PURPOSE: To investigate clinical and histopathologic manifestations of Chlamydia trachomatis (CT)-induced chronic posterior segment (PS) inflammation in rabbits. METHODS: Fifteen rabbits were divided into three equal groups of CT subconjunctival-only (SC) and subconjunctival plus intravitreal (SC+IV) inoculation, and controls. Both noncontrol groups received a bilateral SC injection (BSI) and the SC+IV group additionally received a unilateral IV injection (UII) of CT L2 culture, whereas the controls received a BSI+UII of phosphate-buffered saline. During 6 months post injection, the animals were investigated for PS inflammation and infection clinically and microbiologically (cell culture, ELISA, and real-time PCR). Hematoxylin-eosin staining and direct immunofluorescence in situ reaction were used to reveal the signs of tissue inflammation and infection. RESULTS: In the SC group, mild PS disorders (eight eyes) involving vitreal infiltration, the following posterior vitreous detachment and chorioretinitis, and severe PS disorders (two eyes) in the form of panuveitis, were developed. In the SC+IV group, mild (three and three eyes that received SC-only and SC+IV injections, respectively) and severe (two and two eyes that received SC-only and SC+IV injections, respectively) PS disorders were developed. A high titer (1:32-1:128) of CT-specific IgM antibody was present in sera from all the noncontrol animals. The CT antigen was detected in the conjunctiva and PS structures (the vitreous, retinal pigment epithelium, and choroid) in 100% and 40% to 75% of all the noncontrol animals, respectively. CONCLUSIONS: Conjunctival or intraocular inoculation with CT may result in invasion of the PS structures and durable persistence thereof, with the development of inflammatory and then degenerative changes. These data might advocate for expanding the role of chronic CT infection in etiology and pathogenesis of vitreoretinal disorders.