Ocular chlamydial infections

Interventions for preventing ophthalmia neonatorum

BACKGROUND

Ophthalmia neonatorum is an infection of the eyes in newborns that can lead to blindness, particularly if the infection is caused by Neisseria gonorrhoeae. Antiseptic or antibiotic medication is dispensed into the eyes of newborns, or dispensed systemically, soon after delivery to prevent neonatal conjunctivitis and potential vision impairment.

OBJECTIVES

1. To determine if any type of systemic or topical eye medication is better than placebo or no prophylaxis in preventing ophthalmia neonatorum. 2. To determine if any one systemic or topical eye medication is better than any other medication in preventing ophthalmia neonatorum.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, and three trials registers, date of last search 4 October 2019. We also searched references of included studies and contacted pharmaceutical companies.  SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials of any topical, systemic, or combination medical interventions used to prevent ophthalmia neonatorum in newborns compared with placebo, no prophylaxis, or with each other.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. Outcomes were: blindness or any adverse visual outcome at 12 months, conjunctivitis at 1 month (gonococcal (GC), chlamydial (CC), bacterial (BC), any aetiology (ACAE), or unknown aetiology (CUE)), and adverse effects.  MAIN RESULTS: We included 30 trials with a total of 79,198 neonates. Eighteen studies were conducted in high-income settings (the USA, Europe, Israel, Canada), and 12 were conducted in low- and middle-income settings (Africa, Iran, China, Indonesia, Mexico). Fifteen of the 30 studies were quasi-randomised. We judged every study to be at high risk of bias in at least one domain. Ten studies included a comparison arm with no prophylaxis. There were 14 different prophylactic regimens and 12 different medications in the 30 included studies. Any prophylaxis compared to no prophylaxis  Unless otherwise indicated, the following evidence comes from studies assessing one or more of the following interventions: tetracycline 1%, erythromycin 0.5%, povidone-iodine 2.5%, silver nitrate 1%. None of the studies reported data on the primary outcomes: blindness or any adverse visual outcome at any time point. There was only very low-certainty evidence on the risk of GC with prophylaxis (4/5340 newborns) compared to no prophylaxis (5/2889) at one month (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.24 to 2.65, 3 studies). Low-certainty evidence suggested there may be little or no difference in effect on CC (RR 0.96, 95% CI 0.57 to 1.61, 4874 newborns, 2 studies) and BC (RR 0.84, 95% CI 0.37 to 1.93, 3685 newborns, 2 studies). Moderate-certainty evidence suggested a probable reduction in risk of ACAE at one month (RR 0.65, 95% 0.54 to 0.78, 9666 newborns, 8 studies assessing tetracycline 1%, erythromycin 0.5%, povidone-iodine 2.5%, silver nitrate 1%, colostrum, bacitracin-phenacaine ointment). There was only very low-certainty evidence on CUE  (RR 1.75, 95% CI 0.37 to 8.28, 330 newborns, 1 study). Very low-certainty evidence on adverse effects suggested no increased nasolacrimal duct obstruction (RR 0.93, 95% CI 0.68 to 1.28, 404 newborns, 1 study of erythromycin 0.5% and silver nitrate 1%) and no increased keratitis (single study of 40 newborns assessing silver nitrate 1% with no events).    Any prophylaxis compared to another prophylaxis Overall, evidence comparing different interventions did not suggest any consistently superior intervention. However, most of this evidence was of low-certainty and was extremely limited.

AUTHORS' CONCLUSIONS

There are no data on whether prophylaxis for ophthalmia neonatorum prevents serious outcomes such as blindness or any adverse visual outcome. Moderate-certainty evidence suggests that the use of prophylaxis may lead to a reduction in the incidence of ACAE in newborns but the evidence for effect on GC, CC or BC was less certain. Comparison of individual interventions did not suggest any consistently superior intervention, but data were limited. A trial comparing tetracycline, povidone-iodine (single administration), and chloramphenicol for GC and CC could potentially provide the community with an effective, universally applicable prophylaxis against ophthalmia neonatorum.

Effects of iota-carrageenan on ocular Chlamydia trachomatis infection in vitro and in vivo

Ocular chlamydial infections with the ocular serovars A, B, Ba, and C of Chlamydia trachomatis represent the world's leading cause of infectious blindness. Carrageenans are naturally occurring, sulfated polysaccharides generally considered safe for food and topical applications. Carrageenans can inhibit infection caused by a variety of viruses and bacteria. To investigate whether iota-carrageenan (I-C) isolated from the red alga Chondrus crispus could prevent ocular chlamydial infection, we assessed if targeted treatment of the conjunctival mucosa with I-C affects chlamydial attachment, entry, and replication in the host cell. Immortalized human conjunctival epithelial cells were treated with I-C prior to C. trachomatis infection and analyzed by flow cytometry and immunofluorescence microscopy. In vivo effects were evaluated in an ocular guinea pig inclusion conjunctivitis model. Ocular pathology was graded daily, and chlamydial clearance was investigated. Our study showed that I-C reduces the infectivity of C. trachomatis in vitro. In vivo results showed a slight reduced ocular pathology and significantly less shedding of infectious elementary bodies by infected animals. Our results indicate that I-C could be a promising agent to reduce the transmission of ocular chlamydial infection and opens perspectives to develop prophylactic approaches to block C. trachomatis entry into the host cell.

Descriptive epidemiology of ophthalmic and ocular adnexal non-Hodgkin's lymphoma

In this article, we provide an update on incidence rates of ophthalmic non-Hodgkin's lymphoma (NHL), in the context of other NHL, in the USA. We also provide population-based estimates of incidence and survival for ocular adnexal NHL, the most common form of ophthalmic NHL, for which descriptive patterns have not been previously reported. Ophthalmic and ocular adnexal NHL have unique incidence patterns, including equal rates among both genders, predominance among Asians/Pacific Islanders, and steady and rapid increases in the past few decades. Studies of international variations in the incidence of ocular adnexal NHL may provide clues as to the underlying mechanisms influencing its unique epidemiology.

Ocular adnexal non-Hodgkin's lymphoma: a review of epidemiology and risk factors

Ocular adnexal non-Hodgkin's lymphoma (NHL), the most common form of ophthalmic NHL, has a unique incidence pattern showing a steady and rapid increase in the past few decades, nearly equal rates among both genders, and predominance among Asians/Pacific Islanders. No major cause for ocular adnexal NHL has been identified, although infectious agents, immune disorders and genetic/epigenetic factors have all been implicated in its etiology. Identifying putative risk factors and biologic mechanisms leading to carcinogenesis in ocular adnexal NHL may enable implementation of effective preventive and/or therapeutic approaches for this malignancy. This article summarizes current knowledge on epidemiology of ocular adnexal NHL and the role of various potential risk factors in its etiology.

Rapidly Increasing Incidence of Ocular Non-Hodgkin Lymphoma

A recent report suggesting that ocular adnexal non-Hodgkin lymphoma (NHL) may be related to Chlamydia psittaci infection underscores the need for reliable epidemiologic data for this malignancy. We examined population-based incidence data from the Surveillance, Epidemiology, and End Results (SEER) Program. During 1992-2001 in the 12 SEER areas, ocular (i.e., eye and adnexa) NHL rates per 100,000 person-years for both sexes were highest among Asians/Pacific Islanders, lower in whites, and lower still in blacks. Incidence increased with advancing age and showed little difference by sex, in contrast to other (extranodal and nodal) NHLs, which occurred predominantly in males. From 1975-2001, there was a rapid and steady increase in incidence of ocular NHL, with annual increases of 6.2% and 6.5% among white males and females, respectively, with no evidence of peaking. By contrast, other NHLs showed evidence of peaking in recent years. The distinctive patterns of ocular NHL call for further studies to identify risk factors and mechanisms, including the potential role of C. psittaci or other infections.

Regression of ocular adnexal lymphoma after Chlamydia psittaci-eradicating antibiotic therapy

PURPOSE

Some infectious agents contributing to lymphomagenesis have been considered targets for new therapeutic strategies. Chlamydia psittaci DNA has been detected in 80% of ocular adnexal lymphomas. The present pilot study was carried out to assess whether C psittaci-eradicating antibiotic therapy is associated with tumor regression in ocular adnexal lymphomas.

PATIENTS AND METHODS

Nine patients with C psittaci-positive marginal-zone B-cell lymphoma of the ocular adnexa at diagnosis or relapse were treated with doxycycline 100 mg, bid orally, for 3 weeks. The presence of C psittaci DNA in peripheral-blood mononuclear cells (PBMCs) was also assessed before and after treatment in seven patients. Objective lymphoma regression was assessed 1, 3, and 6 months after therapy conclusion and every 6 months during follow-up.

RESULTS

All patients completed antibiotic therapy with excellent tolerability. At 1 month from doxycycline assumption, chlamydial DNA was no longer detectable in PBMCs of all four positive patients. Objective response was complete in two patients, partial response (> 50%) was observed in two patients, and minimal response (< 50%) was observed in three patients. Duration of response in the seven responders was 12+, 29+, 31+, 8+, 7+, 2+, and 1+ months, respectively.

CONCLUSION

C psittaci-eradicating antibiotic therapy with doxycycline is followed by objective response in patients with ocular adnexal lymphoma, even after multiple relapses of the disease. A confirmatory, large, phase II trial is warranted to confirm whether this fast, cheap, and well-tolerated therapy could replace other more aggressive strategies as first-line treatment against ocular adnexal lymphomas.

Evidence for an association between Chlamydia psittaci and ocular adnexal lymphomas

BACKGROUND

Ocular adnexal lymphomas may be antigen-driven disorders; however, the source of the putative antigen or antigens is still unknown. Hence, we assessed whether Chlamydiae infection is associated with the development of ocular adnexal lymphomas.

METHODS

The presence of Chlamydia psittaci, trachomatis, and pneumoniae DNA was investigated by polymerase chain reaction in 40 ocular adnexal lymphoma samples, 20 nonneoplastic orbital biopsies, 26 reactive lymphadenopathy samples, and peripheral blood mononuclear cells (PBMCs) from 21 lymphoma patients and 38 healthy individuals. Seven patients with chlamydia-positive PBMCs were treated with the antibiotic doxycycline, and objective response was assessed in four patients with measurable lymphoma lesions. Differences in Chlamydiae DNA detection between the case patients and the control subjects were analyzed using the Fisher exact test. All statistical tests were two-sided.

RESULTS

Thirty-two of the 40 (80%) ocular adnexal lymphoma samples carried C. psittaci DNA, whereas all lymphoma samples were negative for C. trachomatis and C. pneumoniae. In contrast, none of the 20 nonneoplastic orbital biopsies (0% versus 80%; P<.001) and only three of 26 (12%) reactive lymphadenopathy samples (12% versus 80%; P<.001) carried the C. psittaci DNA. Nine of 21 (43%) patients with chlamydia-positive lymphomas carried C. psittaci DNA in their PBMCs, whereas none (0%) of the healthy PBMC donors carried C. psittaci DNA in their PBMCs (43% versus 0%; P<.001). One month after doxycycline treatment, chlamydial DNA was no longer detectable in the PBMCs of all seven treated patients, and objective response was observed in two of the four evaluable patients.

CONCLUSION

Patients with ocular adnexal lymphoma had a high prevalence of C. psittaci infection in both tumor tissue and PBMCs. Persistent C. psittaci infection may contribute to the development of these lymphomas, as was also supported by the clinical responses observed in this study with C. psittaci-eradicating antibiotic therapy.