Analysis of ocular fluids for local antibody production in uveitis

Rubella virus-associated uveitis: The essentiality of aqueous humor virological analysis

AIMS / BACKGROUND

Rubella virus-associated uveitis (RVAU) classically presents with the clinical features of Fuchs uveitis syndrome (FUS). We report a series RVAU, and discuss the relevance of available diagnostic strategies, and how vaccination could potentially prevent disease.

METHODS

We retrospectively included patients with RV-positive aqueous humor (AH) with RT-PCR and/or intraocular RV-IgG production, between January 2014 and December 2019. RV-IgG titers from AH and serum were compared with other virus-specific IgG titers (VZV and/or CMV and/or HSV-1), to determine the derived Goldmann-Witmer coefficient (GWC'). Clinical findings at presentation and during follow-up are reported, as well as the anti-RV vaccination status.

RESULTS

All 13 included patients demonstrated intraocular synthesis of RV-IgG (median GWC': 9.5; 3.2-100). RV-RNA was detected in one patient while PCR results were negative for other HSV1, VZV and CMV. The mean delay in diagnosis was 13 ± 12.6 years, with an initial presentation of FUS in only 3 patients (23%). Only four patients had been vaccinated, but all after the recommended age.

CONCLUSION

As RVAU is a pleiomorphic entity, virological analysis (RV RT-PCR and GWC') of aqueous humor is essential to improve the diagnosis and management of this entity. Improper vaccination against RV appears to be implicated in RVAU.

[Ocular manifestations of viral diseases]

Les infections virales peuvent toucher l’ensemble des tuniques oculaires et mettre en jeu la fonction visuelle à plus ou moins courte terme. Les kératites et kérato-uvéites liées au virus HSV-1 sont les atteintes les plus fréquentes. Les récurrences entraînent une opacification cornéenne irréversible qui en fait la première cause de cécité d’origine infectieuse dans les pays occidentaux, et justifient un traitement antiviral préventif au long cours. Le zona ophtalmique (10 à 20 % des zonas), peut s’accompagner d’atteintes oculaires sévères (kératites, kérato-uvéites), dont 30 % deviennent chroniques/récurrentes, et de douleurs post-zostériennes, redoutables dans le territoire trigéminé. Les rétinites nécrosantes liées aux herpesvirus (HSV, VZV, CMV), sont rares mais constituent des urgences fonctionnelles absolues nécessitant un traitement antiviral par voie intraveineuse et intravitréenne. Les conjonctivites à adénovirus constituent la première cause de conjonctivite infectieuse. Le plus souvent bénignes, elles sont extrêmement contagieuses et peuvent se compliquer de lésions cornéennes invalidantes persistant plusieurs mois, voire années. Certaines arboviroses s’accompagnent de manifestations oculaires inflammatoires. Dans le cas du Zika, les infections congénitales peuvent se compliquer d’atrophie maculaire et/ou optique. Les conjonctivites sont très fréquentes à la phase aiguë de la maladie à virus Ebola, dont 15 % des survivants présentent des atteintes inflammatoires chroniques sévères liées à la persistance du virus dans les tissus uvéaux. Enfin, dans le cadre de la COVID-19, les conjonctivites ne sont pas très fréquentes mais peuvent être inaugurales, voire au premier plan et sont associées à une excrétion virale lacrymale qui doit faire prendre toutes les précautions.

Polymerase chain reaction in unilateral cases of presumed viral anterior uveitis

Background and objectives

Anterior uveitis is the most common form of intraocular inflammation. The main aim of this study was to determine the viral etiology in patients with unilateral cases of anterior uveitis.

Patients and methods

A total of 12 consecutive patients with the diagnosis of idiopathic unilateral anterior uveitis were included prospectively. Aqueous specimens were obtained from each patient by anterior chamber paracentesis and subjected to the detection of viral DNA/RNA genome by polymerase chain reaction assay for herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein–Barr virus, and rubella virus.

Results

There were six male and six female patients. The mean age was 43 years, with an age range of 11–82 years. All 12 cases presented with unilateral anterior uveitis. In four (33%) patients, polymerase chain reaction was positive for viral genome. Two patients were positive for herpes simplex virus type 1, one patient was positive for cytomegalovirus and one for Epstein–Barr virus.

Conclusion

Recent molecular diagnostic assays would help in the identification of the causative agent in patients with unilateral anterior uveitis.

Recent developments in the treatment of posterior uveitis

Uveitis is an intraocular inflammation that can be caused by infection, autoimmune disease, trauma or malignancy. It is a serious cause of visual handicap and therapy is targeted at: removal of possible infectious agents, the immunological processes that lead to or sustain the inflammation and finally to prevent or treat the destructive effects of the inflammation on the delicate ocular structures. In this review the latest developments concerning the treatment of posterior uveitis are illuminated, e. g., new approaches concerning the treatment of infectious uveitis including the therapy of herpes virus (VZV, HSV and CMV), bacterial and toxoplasma infections of the eye. Several new ways to influence the immune response and inflammation are described including the use of interferons, modulation of cytokines, soft steroids, other new immunosuppressive drugs and treatment of autoimmune uveitis by oral tolerization. An overview is given to illustrate new ways to administer drugs into eyes, such as intravitreal devices. Finally new developments in the field of the treatment of the various complications of uveitis (cystoid macular edema) are described.

Ocular toxoplasmosis II: clinical features, pathology and management

The term, ocular toxoplasmosis, refers to eye disease related to infection with the parasite, Toxoplasma gondii. Recurrent posterior uveitis is the typical form of this disease, characterized by unilateral, necrotizing retinitis with secondary choroiditis, occurring adjacent to a pigmented retinochoroidal scar and associated with retinal vasculitis and vitritis. Multiple atypical presentations are also described, and severe inflammation is observed in immunocompromised patients. Histopathological correlations demonstrate focal coagulative retinal necrosis, and early in the course of the disease, this inflammation is based in the inner retina. For typical ocular toxoplasmosis, a diagnosis is easily made on clinical examination. In atypical cases, ocular fluid testing to detect parasite DNA by polymerase chain reaction or to determine intraocular production of specific antibody may be extremely helpful for establishing aetiology. Given the high seroprevalence of toxoplasmosis in most communities, serological testing for T. gondii antibodies is generally not useful. Despite a lack of published evidence for effectiveness of current therapies, most ophthalmologists elect to treat patients with ocular toxoplasmosis that reduces or threatens to impact vision. Classic therapy consists of oral pyrimethamine and sulfadiazine, plus systemic corticosteroid. Substantial toxicity of this drug combination has spurred interest in alternative antimicrobials, as well as local forms of drug delivery. At this time, however, no therapeutic approach is curative of ocular toxoplasmosis.

Real-time polymerase chain reaction and intraocular antibody production for the diagnosis of viral versus toxoplasmic infectious posterior uveitis

PURPOSE

The aim of this work was to determine the diagnostic performance of real-time polymerase chain reaction (RT-PCR) and to assess intraocular specific antibody secretion (Goldmann-Witmer coefficient) on samples from patients with signs of posterior uveitis presumably of infectious origin and to target the use of these two biologic tests in the diagnostic of Toxoplasma/viral Herpesviridae posterior uveitis by the consideration of clinical behavior and delay of intraocular sampling.

METHODS

Aqueous humour and/or vitreous fluid were collected from patients suspected of having posterior uveitis of infectious origin at presentation (140 samples). The diagnosis was confirmed by quantification of antibodies with the Goldmann-Witmer coefficient (GWC) and for detection of Herpesviridae and Toxoplasma gondii genomes with RT-PCR. Forty-one patients had final diagnosis of uveitis of non-Toxoplasma/non-viral origin and 35 among them constituted the control group. The main outcome measures were sensitivity, specificity, and positive and negative predictive values (PPV and NPV).

RESULTS

When pre-intraocular testing indication was compared with final diagnosis, GWC was a more sensitive and specific method than RT-PCR, and was successful in detecting T. gondii, especially if the patient is immunocompetent and the testing is carried out later in the disease course, up to 15 months. For viral Herpesviridae uveitis, the sensitivity and PPV of PCR evaluation was higher than detected with GWC with respectively 46% compared with 20% for sensitivity and 85% versus 60% for PPV. In either viral retinitis or toxoplasmosis infection, RT-PCR results were positive from 24 h, although GWC was not significant until 1 week after the onset of signs. In toxoplasmosis patients, positive RT-PCR results were statistically correlated with the chorioretinitis area (more than three disc areas; p = 0.002), with the age older than 50 (p = 0.0034) and with a clinical anterior inflammation (Tyndall ≥1/2+) and panuveitis; (p = 0.0001).

CONCLUSIONS

For the diagnosis of viral or toxoplasmosis-associated intraocular inflammation, the usefulness of laboratory diagnosis tools (RT-PCR and GWC) depends on parameters other than the sensitivity of the tests. Certain patient characteristics such as the age of the patients, immune status, duration since the onset of symptoms, retinitis area, predominant site and extent of inflammation within the eye should orientate the rational for the choice of laboratory testing in analysis of intraocular fluids.

Anterior chamber paracentesis in patients with acute elevation of intraocular pressure

PURPOSE

The purpose was to evaluate the efficacy and the safety of anterior chamber paracentesis (ACP) in acute elevation of intraocular pressure (IOP).

METHODS

We prospectively enrolled 20 patients who presented with acute unilateral elevation of IOP above 50 mmHg. IOP was measured before, 10 min, and 1, 7 and 30 days after ACP. The outcome at 1 year was available in 19 patients.

RESULTS

The patients included 14 cases of primary acute angle-closure attacks and six cases of secondary glaucoma. IOP decreased from 53.4 +/- 4.2 mmHg to 24.1 +/- 12.5 mmHg at 10 min, to 18.2 +/- 11.1 mmHg at 24 h, and to 16.4 +/- 10.7 mmHg 7 days after ACP. ACP combined with antiglaucomatous medications provided immediate relief of symptoms in all cases and improvement of corneal oedema in 17 cases. We noted three failures in secondary glaucoma. We performed a laser peripheral iridotomy (LPI) in 14 patients and a surgical procedure in 17 eyes. No complications related to ACP were observed.

CONCLUSION

ACP is a safe and effective procedure for acute elevation of IOP in acute primary primary angle-closure but only remains an add-on therapy to usual treatments. However, this technique must be evaluated in larger series.

Polymerase chain reaction detection of Neisseria meningitidis in the intraocular fluid of a patient with endogenous endophthalmitis but without associated meningitis

PURPOSE

To report a patient with Neisseria meningitidis endophthalmitis without associated meningitis with full visual recovery, with early detection of the microorganism using polymerase chain reaction (PCR) analysis.

DESIGN

Retrospective, observational case report.

PARTICIPANTS

One patient with endogenous endophthalmitis.

METHODS

Polymerase chain reaction analysis and culture of the intraocular fluid sample. Polymerase chain reaction analysis was performed with a universal (16S rRNA) primer set to detect bacterial DNA, and subsequently a specific probe was used to detect Neisseria species DNA.

RESULTS

The 16S rRNA primers detected bacterial DNA, the specific probe detected Neisseria species DNA, and culture was positive for Neisseria meningitidis serotype C.

CONCLUSIONS

A universal bacterial PCR can be very helpful for the diagnosis of endogenous bacterial endophthalmitis at an early stage of the disease.

Diagnosis of toxoplasmic retinochoroiditis with atypical clinical features

PURPOSE

To determine the value of aqueous humor analysis for confirming the diagnosis of ocular toxoplasmosis in patients who present with atypical clinical features and to relate the results of local antibody production and polymerase chain reaction (PCR) with the extent of active retinitis and the immune status of the patient.

DESIGN

Retrospective case series.

METHODS

Sixty-seven consecutive patients with retinitis or retinochoroiditis that was clinically consistent with atypical ocular toxoplasmosis underwent diagnostic anterior chamber paracentesis and serological studies. The aqueous humor was analyzed both by PCR to detect Toxoplasma gondii B1 gene and by the Goldman-Witmer coefficient to determine levels of local anti-T. gondii antibody production.

RESULTS

In nine of the 67 cases, PCR was positive for T. gondii; seven of these were negative for local antibody production. All nine patients had illnesses associated with immunosuppression or advanced old age and all had active retinitis with a mean area of 11.5 disk areas (DA). Twenty-five of the remaining 58 cases were positive for local antibody production. These 25 had a mean area of active retinitis measuring 2.6 DA, and 24 of these patients were immunocompetent. All 34 cases with laboratory evidence of ocular toxoplasmosis diagnosed by either method responded to anti-T. gondii agents. The remaining 33 were negative for T. gondii infection by these two methods; some had laboratory evidence of other infections.

CONCLUSIONS

Although in the present study, the sensitivity and specificity of the aqueous humor PCR and Goldman-Witmer coefficient could not be ascertained in the laboratory diagnosis of toxoplasmic retinochoroiditis, the PCR method appears to confirm the diagnosis in immunocompromised individuals with large atypical foci of retinitis. Conversely, determination of local antibody production may be appropriate for proper diagnosis in immunocompetent individuals presenting with small foci of retinitis.

Toxoplasmosis, an overview with emphasis on ocular involvement

Toxoplasmosis is a common parasitic zoonosis and an important cause of abortions, mental retardation, encephalitis, blindness, and death worldwide. Although a large body of literature has emerged on the subject in the past decades, many questions about the pathogenesis and treatment of the disease remain unanswered. This review aims to provide an overview of the current insights regarding the causative parasite and the mechanisms leading to symptomatic infection with emphasis on ocular toxoplasmosis.

Evidence for a compartmentalized B cell response as characterized by IgG epitope specificity in human ocular toxoplasmosis

Infectious agents in the eye induce both a local and a systemic humoral immune response. Previously, differences in Ag recognition were observed between systemic and ocular derived IgG of patients with ocular toxoplasmosis. This finding implied a nonrandom distribution of IgG-producing B cells in the inflamed eye. In the present study, we compared the intraocular and systemic B cell responses of patients with ocular toxoplasmosis to a single Toxoplasma gondii Ag. Two series of C-terminally deleted recombinant T. gondii GRA-2 proteins were constructed to delineate IgG B cell epitopes of paired ocular and serum samples. Differences in epitope region recognition between the ocular and systemic compartment were detected in 9 of 13 patients. The difference in distribution of GRA-2 epitopes between paired samples is indicative of a local GRA-2 specific B cell population functionally different from the systemic GRA-2-specific B cell population. Our results suggest a selective activation of a subset of B cells locally in nonlymphoid tissue.

Demonstration of Bartonella grahamii DNA in Ocular Fluids of a Patient with Neuroretinitis

We describe the clinical and laboratory features of a 55-year-old human immunodeficiency virus-negative female patient who presented with bilateral intraocular inflammatory disease (neuroretinitis type) and behavioral changes caused by a Bartonella grahamii infection. Diagnosis was based on the PCR analysis of DNA extracted from the intraocular fluids. DNA analysis of the PCR product revealed a 100% identity with the 16S rRNA gene sequence of B. grahamii . The patient was successfully treated with doxycycline (200 mg/day) and rifampin (600 mg/day) for 4 weeks. This is the first report that demonstrates the presence of a Bartonella species in the intraocular fluids of a nonimmunocompromised patient and that indicates that B. grahamii is pathogenic for humans.

Diagnostic anterior chamber paracentesis in uveitis: a safe procedure?

BACKGROUND

Differentiation between infectious and non-infectious uveitis is of crucial value for accurate management of patients with uveitis. Tests performed on aqueous humour yield more relevant information than those done in serum. The objective of this study was to evaluate whether the aqueous humour tap for diagnostic purposes is a safe procedure to perform in uveitis patients.

METHODS

In this retrospective study 361 patients with uveitis, who underwent a diagnostic anterior chamber paracentesis in an outpatient clinic, were investigated. 72 of the 361 patients were examined 30 minutes after the puncture. The site of the paracentesis, the depth of the anterior chamber, and cells in the anterior chamber were examined. All 361 patients were evaluated within 2 weeks after the paracentesis was performed. The final follow up period varied from 6 months to more than 3 years. The clinical data were analysed with the emphasis on the occurrence of cataract and a history of corneal infections or endophthalmitis.

RESULTS

In this series no serious side effects such as cataract, keratitis, or endophthalmitis were observed. The depth of the anterior chamber of all evaluated patients was restored after 30 minutes. In five out of 72 cases (three AIDS patients with cytomegalovirus retinitis and two patients with anterior uveitis due to herpes simplex virus) a small hyphaema was observed 30 minutes after the paracentesis took place.

CONCLUSION

Anterior chamber paracentesis appears to be a safe procedure in the hands of an experienced ophthalmologist.

Aetiology of uveitis in Sierra Leone, west Africa

BACKGROUND

In 1992, non-onchocercal uveitis caused 9% of blindness, 8% of visual impairment, and 11% of uniocular blindness among patients visiting an eye hospital in Sierra Leone, west Africa. The aim of this study was to determine the aetiology of uveitis in this population.

METHODS

General and ophthalmic examination complemented by serum and aqueous humour analyses for various infectious agents was performed for 93 uveitis patients and compared with serum (n = 100) and aqueous humour (n = 9) analysis of endemic controls.

RESULTS

At the initial examination, 45 patients (48%) proved to be severely visually handicapped. After clinical and laboratory analyses, an aetiological diagnosis was established for 49 patients (52%). Toxoplasma gondii was the most important cause of uveitis (40/93; 43%). Anti-toxoplasma IgM antibodies were detected in serum samples of seven of 93 patients (8%) compared with one of 100 controls (1%, p < 0.05). At least six patients (15%) with ocular toxoplasmosis had acquired the disease postnatally. Antibodies against Treponema pallidum were detected in 18 of 92 patients (20%) and in 21 controls (21%). Other causes of uveitis were varicella zoster virus (one patient), herpes simplex virus (two patients), and HLA-B27 positive acute anterior uveitis with ankylosing spondylitis (one patient), while one patient had presumed HTLV-I uveitis.

CONCLUSIONS

In a hospital population in Sierra Leone, west Africa, uveitis was associated with severe visual handicap and infectious diseases. Toxoplasmosis proved to be the most important cause of the uveitis. Although the distribution of congenital versus acquired toxoplasmosis in this population could not be determined, the results indicate an important role of postnatally acquired disease. The results further suggested minor roles for HIV, tuberculosis, toxocariasis, and sarcoidosis as causes of uveitis in this population.