Searching for viral antibodies and genome in intraocular fluids of patients with Fuchs uveitis and non-infectious uveitis

Comparative analysis of iridian anterior segment OCT and microbiological features in Fuchs Uveitis Syndrome and Posner-Schlossman Syndrome

PURPOSE

To compare iridian Swept-Source Anterior Segment OCT (SS-AS-OCT) and microbiological features in Aqueous Humor (AH) in patients with Fuchs Uveitis Syndrome (FUS) and Posner-Schlossman Syndrome (PSS).

METHODS

Comparative, retrospective-prospective single center study examining 131 eyes from 66 patients, including 33 eyes with PSS, 37 eyes with FUS, and 61 healthy eyes. AH samples were collected from affected eyes in all patients. Cross-sectional 6 mm SS-AS-OCT B-scans were taken from iris quadrants and analyzed for Stromal Thickness (ST), Smooth Index (SI), and Optical Density (OD) with ImageJ®. Statistical analysis was performed using SPSS®.

RESULTS

Among 32 PSS patients, Cytomegalovirus (CMV) was detected in 21 (65.5%). Of 34 FUS patients, 22 (64.7%) tested positive for Rubella Virus (RV) and one for CMV (2,9%). FUS eyes showed decreased ST compared to PSS ones in the superior (328.2 ± 49.4 vs 352.2 ± 47.4; p = 0.010) and temporal (322.6 ± 54.4 vs 294.3 ± 47.9; p = 0.024) quadrants. FUS eyes had a higher mean SI (p = 0.021), notably in the temporal quadrant (p = 0.002). Both FUS and PSS eyes showed significant differences in all parameters compared to healthy eyes, except for ST and OD in the temporal quadrant in PSS, and OD in the nasal quadrant in FUS. Quantitative analysis of iris OCT images showed that RV-related and non-RV-related FUS eyes were similar, as were CMV-associated and non-CMV-associated PSS eyes.

CONCLUSIONS

CMV and RV were found to be the main etiologies of PSS and FUS respectively. Quantitative analysis of iris OCT images has proved to be an objective method to differentiate between these two syndromes.

KEY MESSAGES

What is known The etiopathogenesis of Fuchs Uveitis Syndrome (FUS) and Posner-Schlossman Syndrome (PSS) remains under discussion. Viral etiology is the most widely accepted theory: Rubella virus (RV) has been associated mostly with FUS and cytomegalovirus (CMV) with PSS. Although FUS and PSS are distinct conditions, their differential diagnosis can be challenging at times due to clinical similarities, particularly iris damage. What is new The quantitative analysis of iris images from Swept Source Anterior Segment OCT is an objective, reliable, and non-invasive method that allows differentiation between FUS and PSS. In this study, RV in FUS and CMV in PSS have been detected in almost 2/3 of patients. This is the first study to perform a comparative analysis of aqueous humor results between PSS and FUS along with the examination of iris images using SS-AS-OCT.

Viral Anterior Uveitis: A Practical and Comprehensive Review of Diagnosis and Treatment

Anterior uveitis is the most common type of uveitis worldwide. The etiologies of anterior uveitis can be divided into infectious and non-infectious (idiopathic, autoimmune, autoinflammatory, trauma, and others). The viral pathogens most commonly associated with infectious anterior uveitis include Herpes Simplex Virus, Varicella-Zoster Virus, Cytomegalovirus, and Rubella Virus. Other emerging causes of viral anterior uveitis are West Nile Virus, Human-Immunodeficiency Virus, Epstein-Barr Virus, Parechovirus, Dengue Virus, Chikungunya Virus, and Human Herpesvirus type 6,7, and 8. Early recognition allows prompt management and mitigates its potential ocular complications. This article provides an updated literature review of the epidemiology, clinical manifestations, diagnostic tools, and treatment options for viral anterior uveitis.

Cytomegalovirus Anterior Uveitis: Clinical Manifestations, Diagnosis, Treatment, and Immunological Mechanisms

Little is known regarding anterior uveitis (AU), the most common ocular disease associated with cytomegalovirus (CMV) infection in immunocompetent populations. CMV AU is highly prevalent in Asia, with a higher incidence in men. Clinically, it manifests mainly as anterior chamber inflammation and elevated intraocular pressure (IOP). Acute CMV AU may resemble Posner-Schlossman syndrome with its recurrent hypertensive iritis, while chronic CMV AU may resemble Fuchs uveitis because of its elevated IOP. Without prompt treatment, it may progress to glaucoma; therefore, early diagnosis is critical to prognosis. Knowledge regarding clinical features and aqueous humor analyses can facilitate accurate diagnoses; so, we compared and summarized these aspects. Early antiviral treatment reduces the risk of a glaucoma surgery requirement, and therapeutic effects vary based on drug delivery. Both oral valganciclovir and topical ganciclovir can produce positive clinical outcomes, and higher concentration and frequency are beneficial in chronic CMV retinitis. An extended antiviral course could prevent relapses, but should be limited to 6 months to prevent drug resistance and side effects. In this review, we have systematically summarized the pathogenesis, clinical features, diagnostic and therapeutic aspects, and immunological mechanisms of CMV AU with the goal of providing a theoretical foundation for early clinical diagnosis and treatment.

Aqueous Humor Analysis in Overlapping Clinical Diagnosis of Cytomegalovirus and Rubella Virus Anterior Uveitis

Background and Objectives: A cross-sectional single-center study was conducted to investigate the etiology in hypertensive anterior uveitis whose clinical features are not fully distinctive from cytomegalovirus or from rubella virus and to demonstrate the possible coexistence of both these viruses in causing anterior uveitis. Materials and Methods: The clinical charts of a cohort of patients with hypertensive viral anterior uveitis of uncertain origin consecutively seen in a single center from 2019 to 2022 were retrospectively reviewed; data on the clinical features, aqueous polymerase chain reaction, and antibody response to cytomegalovirus and rubella virus were collected. Results: Forty-three eyes of as many subjects with viral anterior uveitis of uncertain origin were included. Thirty-two patients had an aqueous polymerase chain reaction or antibody index positive to cytomegalovirus only, while 11 cases had an aqueous antibody response to both cytomegalovirus and rubella virus. This latter overlapping group had a statistically significant higher rate of hypochromia and anterior vitritis (p-value: 0.02 and < 0.001, respectively). Conclusions: The simultaneous presence of intraocular antibodies against cytomegalovirus and rubella virus could redefine the differential diagnosis of hypertensive viral anterior uveitis, demonstrating a possible “converged” immune pathway consisting in a variety of stimuli.

Could different aqueous humor and plasma cytokine profiles help differentiate between ocular sarcoidosis and ocular tuberculosis?

OBJECTIVE AND DESIGN

A cross-sectional single-center study was conducted to assess cytokine levels in aqueous humor (AH) and plasma of three different uveitis entities: definite ocular sarcoidosis (OS), definite OS associated with QuantiFERON®-TB Gold test positivity (Q + OS) and presumed tubercular uveitis (TBU).

SUBJECTS

Thirty-two patients (15 OS, 5 Q + OS, 12 TBU) were included.

METHODS

Quantification of selected cytokines was performed on blood and AH samples collected before starting any treatment. Statistical analysis was conducted using the Kruskal-Wallis test, the Mann-Whitney or Fisher test and the Principal Component Analysis (PCA).

RESULTS

IL-6, IL-8 and IP-10 levels were higher in AH samples than in peripheral blood. In AH samples, BLC, IL-8 and IP-10 were significantly higher in definite OS than in presumptive TBU. There were no statistically significant differences in terms of cytokine levels between Q + OS and presumptive TBU. PCA showed a similar cytokine pattern in the latter two groups (IFNγ, IL-15, IL-2, IP-10, MIG), while the prevalent expression of BLC, IL-10 and MIP-3 α was seen in definite OS.

CONCLUSIONS

The different AH and plasma cytokine profiles observed in OS compared to Q + OS and TBU may help to differentiate OS from TBU in overlapping clinical phenotypes of granulomatous uveitis (Q + OS).

Absence of Herpesvirus DNA in Aqueous Humor from Asymptomatic Subjects

Purpose

To assess herpesvirus DNA detection in aqueous humor from a cohort of asymptomatic Scandinavian patients undergoing elective cataract surgery.

Patients and Methods

Prospective case series. Aqueous samples were obtained from 30 patients undergoing elective cataract surgery. Polymerase chain reaction (PCR) analysis for herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), cytomegalovirus (CMV), Epstein Barr virus (EBV) was performed. Toxoplasma was added to the analysis due to its role as pathogen with ocular latency.

Results

Mean age of participants was 75.3 years. Sixteen subjects (53%) had ocular comorbidities. Five subjects (17%) had endothelial dysfunction without known hereditary pattern. None of the samples were positive for herpesviruses or toxoplasma.

Conclusion

None of the aqueous samples were positive, suggesting shedding does not frequently occur in the aqueous humor of asymptomatic patients.

Epidemiology of Viral Induced Anterior Uveitis

Purpose: Viral agents are the most common cause of infectious anterior uveitis worldwide. The purpose of this review is to analyze the frequency, gender and racial differences of viral anterior uveitis (VAU) in various populations.Methods: Systematized literature review of epidemiological reports of VAU cited in PubMed, EMBASE and the Cochrane Library database published until June 30th, 2020.Results: A total of 12 clinical studies on epidemiology of definite VAU and 36 clinical studies of presumed VAU were identified. Members of Herpesviridae family represent the most common causes of VAU. Other less frequently reported causes, such as rubella and endemic viruses (HTLV-1, Chikungunya, Dengue, Ebola, Zika virus) were also analyzed.Conclusion: HSV, VZV are prevalent worldwide. CMV is more frequent in Asia, and rubella in the West. However, due to globalization and air travel, HTLV-1, Chikungunya, Dengue and Ebola may become important causes of VAU across the world.

Inflammatory markers of complete blood count in Fuchs uveitis syndrome

OBJECTIVE

To evaluate inflammatory indices of complete blood count (CBC) in patients with Fuchs uveitis syndrome (FUS), and to compare the results with healthy individuals.

DESIGN

Cross-sectional, comparative study.

PARTICIPANTS

A total of 140 participants were included in the study and divided into 2 groups: 70 patients diagnosed with FUS (FUS group) and 70 healthy individuals (control group).

METHODS

The groups were compared in terms of ocular examination findings and CBC parameters. The independent samples t test was used to examine variables between the groups. The Pearson correlation test was performed to analyze correlation among the severity of anterior chamber reaction, duration of FUS, and CBC indices.

RESULTS

The mean lymphocyte count and lymphocyte-to-monocyte ratio (LMR) were significantly higher in the FUS group than in the control group (p = 0.001 and p < 0.001, respectively). The mean monocyte count and neutrophil-to-lymphocyte ratio (NLR) were significantly lower in the FUS group than in the control group (p = 0.010 and p = 0.003, respectively). In the receiver operating characteristic curve analysis, the area under the curve (AUC) for LMR was 0.834, with a sensitivity of 82.6% and a specificity of 80.0%. The AUC for NLR was 0.789, with a sensitivity of 71.2% and a specificity of 70.0%. LMR was positively correlated with duration of FUS (p = 0.001, r = 0.574).

CONCLUSIONS

Our findings suggest that decreased NLR and increased LMR values may be markers indicating impaired blood-aqueous barrier function in FUS.

[Viral and non-viral infections in the etiopathogenesis of uveitis]

The article reviews literature and proprietary data on the role of pathogens in the etiology of infectious and non-infectious uveitis. Infectious uveitis is caused by active intraocular replication of the virus (herpesvirus, acute stage of enterovirus), or by long-term persistence of the viruses in eye tissues (Fuchs syndrome associated with rubella virus, late complications of enterovirus uveitis). Clinical picture, severity, outcomes of infectious uveitis depend on the pathogen, adequacy of the immune response and genetic characteristics of the patient. Infections trigger the development of non-infectious uveitis, including autoimmune. Their trigger mechanisms involve antigenic mimicry, bystander activation, epitope spreading, presence of superantigens, intestinal microbiota. An uncontrolled, excessive host immune response contributes to cell destruction even after removal of the infection.

Cytokine Profiling in Aqueous Humor Samples From Patients With Non-Infectious Uveitis Associated With Systemic Inflammatory Diseases

Non-infectious uveitis are intraocular inflammatory conditions caused by dysregulated activation of the immune response without any detectable infectious agents. The aim of this study was to explore potential markers and therapeutic targets for two distinct types of non-infectious uveitis associated with Behçet's disease (BD) and Vogt Koyanagi Harada (VKH) disease. Concentrations of 27 cytokines were investigated in aqueous humor (AH) samples from patients with active uveitis vs. healthy controls (HC) (n = 10 patients with BD-associated uveitis; n = 10 patients with VKH-associated uveitis; n = 10 HC) using the Bio-Plex Pro^TM human cytokine group I panel. Additionally, leukocytes in AH samples were counted with hemocytometers and characterized by flow cytometry. Eleven cytokines were differentially expressed between patients with uveitis and HC with a median concentration greater than 10 pg/ml. IL-6, IP-10, G-CSF, and IFNγ showed higher concentrations in AH samples from both BD and VKH patients while IL-2, IL-8, IL-13, TNFα, eotaxin, IL-1ra showed statistically significant higher concentrations only in AH samples from BD patients. GM-CSF was the sole cytokine with an opposite profile showing decreased levels in AH samples from BD patients. IL-1ra and IL-6 were detected at higher frequencies in AH samples from BD and VKH patients compared with those from HC while IFNγ and TNFα were not detected in HC. The concentrations of IL-6, IL-8, IP-10, G-CSF, IFNγ, TNFα, eotaxin, IL-1ra positively correlated with the concentrations of leukocytes in AH, suggesting that such cytokines can be produced by immune cells and/or attract and/or promote proliferation and survival of immune cells in these types of uveitis. The correlation matrix of cytokine concentrations in AH samples revealed that IFNγ, TNFα, eotaxin, IL-6, G-CSF highly correlated each other. The ratios of cytokine concentrations between AH and plasma intra-individuals showed that IL-2, IL-6, IP-10, GM-CSF were increased intraocularly. In conclusion, AH sampling followed by multiplex analysis of cytokines should be fostered in non-infectious uveitis to identify cytokines dysregulated intraocularly in each individual laying the groundwork for precision medicine.

PCR Multiplex for CMV Detection in Patients with Anterior Uveitis

PURPOSE

Describing the utility of Polymerase Chain Reaction for Cytomegalovirus (CMV-PCR) in the diagnosis of suspected viral anterior uveitis (AU).

PATIENTS AND METHODS

We analyzed aqueous humor (AH) CMV-PCR positivity and treatment modifications in 47 eyes of 46 patients with viral uveitis and its correlation with high intraocular pressure (HIOP), uveitis clinical characteristics and time intervals from samples to uveitis diagnosis and to relapse.

RESULTS

CMV-PCR positive results occurred in 13 eyes (27.7%) of 12 patients. They were more frequent in HIOP eyes (34.2%, p = 0.047) and with Posner-Schlossman Syndrome (56.2%, p = 0.002). CMV-PCR positivity (p = 0.001) and HIOP (p = 0.038) increased the probability of treatment change. Although CMV-PCR positive results decreased over time (p = 0.002), they were not related to activity or proximity to inflammatory uveitis episode.

CONCLUSION

HIOP AU eyes should be considered for CMV-PCR AH analysis due to possible treatment modifications.

Changes in patterns of uveitis at a tertiary referral center in Northern Italy: analysis of 990 consecutive cases

PURPOSE

The role of uveitis, an uncommon ocular disease, is often neglected in research and treatment of autoimmune conditions. The study described the spectrum of uveitis at a referral center in North Italy, and compared that to a previously published series of patients.

METHODS

We reviewed all patients with uveitis diagnosed from 2013 to 2015 at the Immunology Eye Unit, Arcispedale S. M. Nuova-IRCCS, Reggio Emilia, Italy. We examined patient characteristics, disease spectrum, and etiologies.

RESULTS

In total, 990 cases of uveitis were identified, who were mostly female (59%) with a median age at presentation of 44 years (interquartile range = 29-57). Anterior uveitis was most frequent (53.5%), followed by panuveitis (22.8%), posterior (16.2%), and intermediate uveitis (5.5%). Anterior herpetic uveitis (15.6%), Fuchs uveitis (9.7%), and HLA-B27 positive anterior uveitis (7.7%) were the most common specific diagnoses. Compared with the previous series, we observed an increased incidence of uveitis, and a different pattern of diagnoses. Rates of herpetic, HLA-B27 positive uveitis, and presumed ocular tuberculosis were higher, but Fuchs uveitis was less frequent.

CONCLUSIONS

The pattern of uveitis appears to be changing, very likely due to population-level increases in infectious diseases, to the availability of new diagnostic tests and to the interdisciplinary approach used in patient diagnosis.

Effects of Fuchs uveitis syndrome on the ultrastructure of the anterior lens epithelium: A transmission electron microscopic study

PURPOSE

The purpose of the study was to investigate the electron microscopic findings of the lens epithelial cells (LECs) in patients with Fuchs uveitis syndrome (FUS) who suffered from cataracts and to compare those with age-matched controls.

METHODS

This study was a prospective, comparative case series. The anterior lens capsules (ALC: basement membrane and associated LECs) were taken from 12 eyes of 12 cases of FUS and ten eyes of ten control patients. The ALCs were obtained from cataract surgery and prepared for transmission electron microscopy (TEM).

RESULTS

There were no statistically significant differences regarding the age or gender between the FUS group and the control group (P > 0.05). In the TEM examinations of the ALCs, all of the FUS cases revealed similar significant ultrastructural changes when compared to the control patients. In the FUS group, the LECs showed homogeneous thickening and irregularity which included some small vacuoles in different areas of the epithelial tissue. Moreover, in some areas of the LECs, widespread, oval-shaped, pigment clusters were detected. Conversely, in the control group, the LECs and all of their elements were in normal ultrastructural patterns, with the exception of some small intraepithelial vacuoles which were fewer and smaller than those in the FUS group.

CONCLUSION

Ultrastructural analysis of the ALC of the patients with FUS disclosed some significant alterations which may be related to the summation of oxidative stress, intraocular inflammation, and iris atrophy.

Rubella

Rubella remains an important pathogen worldwide, with roughly 100,000 cases of congenital rubella syndrome estimated to occur every year. Rubella-containing vaccine is highly effective and safe and, as a result, endemic rubella transmission has been interrupted in the Americas since 2009. Incomplete rubella vaccination programmes result in continued disease transmission, as evidenced by recent large outbreaks in Japan and elsewhere. In this Seminar, we provide present results regarding rubella control, elimination, and eradication policies, and a brief review of new laboratory diagnostics. Additionally, we provide novel information about rubella-containing vaccine immunogenetics and review the emerging evidence of interindividual variability in humoral and cell-mediated innate and adaptive immune responses to rubella-containing vaccine and their association with haplotypes and single-nucleotide polymorphisms across the human genome.

Current aspects on the management of viral uveitis in immunocompetent individuals

Viruses are a fundamental etiology of ocular inflammation, which may affect all structures of the organ. Advances in molecular diagnostics reveal an increasingly broader spectrum of virus-associated intraocular inflammation, including all members of the herpes family, rubella virus, and other more rare causes such as Epstein–Barr and chikungunya virus. In particular, viruses of the herpes family are important causes of anterior and posterior uveitis. Owing to their often fulminant clinical course and persistence in ocular tissues, a clear differential diagnosis between alpha- and beta-type herpes viruses is essential to guide acute and long-term treatment. Here, we review the epidemiology, clinical, and laboratory findings of virus-associated uveitis with emphasis on their therapy and management and include our own experience.