Interleukins and cytokine biomarkers in uveitis

Cytokines in Immune-mediated "Non-infectious" Uveitis

Uveitis is a significant cause of ocular morbidity and accounts for approximately 5 - 10% of visual impairments worldwide, particularly among the working-age population. Infections are the cause of ~ 50% cases of uveitis, but it has been suggested that infection might also be implicated in the pathogenesis of immune-mediated "non-infectious" uveitis. There is growing evidence that cytokines (i.e., interleukins, interferons, etc.) are key mediators of immune-mediated "non-infectious" uveitis. For example, activation of the interleukin-23/interleukin-17 signalling pathway is involved in immune-mediated "non-infectious" uveitis. Studies in animal models have been important in investigating the role of cytokines in uveitis. Recent studies of clinical samples from patients with uveitis have allowed the measurement of a considerable array of cytokines even from very small sample volumes (e.g., aqueous and vitreous humour). The identification of complex patterns of cytokines may contribute to a better understanding of their potential pathogenetic role in uveitis as well as to an improved diagnostic and therapeutic approach to treat these potentially blinding pathologies. This review provides further insights into the putative pathobiological role of cytokines in immune-mediated "non-infectious" uveitis.

NLRP3 and autophagy in retinal ganglion cell inflammation in age-related macular degeneration: potential therapeutic implications

Retinal degenerative diseases were a large group of diseases characterized by the primary death of retinal ganglion cells (RGCs). Recent studies had shown an interaction between autophagy and nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasomes, which may affect RGCs in retinal degenerative diseases. The NLRP3 inflammasome was a protein complex that, upon activation, produces caspase-1, mediating the apoptosis of retinal cells and promoting the occurrence and development of retinal degenerative diseases. Upregulated autophagy could inhibit NLRP3 inflammasome activation, while inhibited autophagy can promote NLRP3 inflammasome activation, which leaded to the accelerated emergence of drusen and lipofuscin deposition under the neurosensory retina. The activated NLRP3 inflammasome could further inhibit autophagy, thus forming a vicious cycle that accelerated the damage and death of RGCs. This review discussed the relationship between NLRP3 inflammasome and autophagy and its effects on RGCs in age-related macular degeneration, providing a new perspective and direction for the treatment of retinal diseases.

Dysregulated Th17/Treg cell axis is correlated with local and systemic immune response in human intermediate uveitis

Th17/Treg cell balance is essential for immune homeostasis and when disrupted, is associated with the occurrence and development of inflammation in numerous autoimmune diseases. However, its contribution in pathophysiology of uveitis remains unexplored. In this study, we deciphered the role of Th17/Treg cell balance in autoimmune uveitis subjects. Using flow cytometry, we detected the frequencies and absolute count of both Th17 and Treg cells in the aqueous humor and peripheral blood of patients and healthy controls. Our results for the first time reveal a significant increase (p < 0.01 and p < 0.005) in Th17 population alongside a significant decrease (p < 0.001 and p < 0.003) in Treg cell population in both the aqueous humor and PBMCs of uveitis patients. Further we analyzed the expression of Th17-Treg associated genes and cytokines via qPCR and ELISA respectively. These findings align with our flow cytometry results, as evident by a significant (p < 0.002) up-regulation of IL-17 and a concurrent down regulation of IL-10 at transcriptional levels. Moreover, IL-17A cytokine was found to be substantially high (p < 0.001) and IL-10 (p < 0.02) down regulated in serum. Interestingly, we demonstrated a significant correlation of Th17/Treg cells in aqueous humor with those in peripheral blood. Conclusively, our results suggest the pivotal role of Th17/Treg cell axis in the immuno-pathophysiology of human uveitis. Further we propose the therapeutic potential of targeting this novel axis for ameliorating the disease burden associated with uveitis.

Reactive Oxygen Species-Responsive Dual Anti-Inflammatory and Antioxidative Nanoparticles for Anterior Uveitis

Anterior uveitis (AU) is an immune-mediated inflammatory disease that results in iritis, cyclitis, glaucoma, cataracts, and even a loss of vision. The frequent and long-term administration of corticosteroid drugs is limited in the clinic owing to the side effects and patient noncompliance with the drugs. Therefore, specifically delivering drugs to inflammatory anterior segment tissues and reducing the topical application dosage of the drug are still a challenge. Here, we developed dual dexamethasone (Dex) and curcumin (Cur)-loaded reactive oxygen species (ROS)-responsive nanoparticles (CPDC NPs) to treat anterior uveitis. The CPDC NPs demonstrated both anti-inflammatory and antioxidative effects, owing to their therapeutic characteristics of dexamethasone and curcumin, respectively. The CPDC NPs could effectively release dexamethasone and curcumin in the oxidizing physiological environment of the inflammation tissue. The CPDC NPs can effectively internalize by activated macrophage cells, subsequently suppressing the proinflammatory factor expression. Moreover, the CPDC NPs can inhibit ROS and inflammation via nuclear transcription factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway activation. In an endotoxin-induced uveitis rabbit model, the CPDC NPs show a therapeutic effect that is better than that of either free drugs or commercial eye drops. Importantly, the CPDC NPs with a lower dexamethasone dosage could reduce the side effects significantly. Taken together, we believe that the dual-drug-loaded ROS-responsive NPs could effectively target and inhibit inflammation and have the potential for anterior uveitis treatment in clinical practice.

Performance of Metagenomic Next-Generation Sequencing of Cell-Free DNA From Vitreous and Aqueous Humor for Diagnoses of Intraocular Infections

BACKGROUND

Delayed diagnosis and improper therapy for intraocular infections usually result in poor prognosis. Due to limitations of conventional culture and polymerase chain reaction methods, most causative pathogens cannot be identified from vitreous humor (VH) or aqueous humor (AH) samples with limited volume.

METHODS

Patients with suspected intraocular infections were enrolled from January 2019 to August 2021. Metagenomic next-generation sequencing (mNGS) was used to detected causative pathogens.

RESULTS

This multicenter prospective study enrolled 488 patients, from whom VH (152) and AH (336) samples were respectively collected and analyzed using mNGS of cell-free DNA (cfDNA). Taking final comprehensive clinical diagnosis as the gold standard, there were 39 patients with indefinite final diagnoses, whereas 288 and 161 patients were diagnosed as definite infectious and noninfectious diseases, respectively. Based on clinical adjudication, the sensitivity (92.2%) and total coincidence rate (81.3%) of mNGS using VH samples were slightly higher than those of mNGS using AH samples (85.4% and 75.4%, respectively).

CONCLUSIONS

Using mNGS of cfDNA, an era with clinical experience for more rapid, independent, and impartial diagnosis of bacterial and other intraocular infections can be expected.

Involvement of the systemic microcirculation in pediatric uveitis

BACKGROUND

Pediatric uveitis is a severe inflammatory ocular condition that can lead to sight-threatening complications and can negatively impact quality of life. The retinal microcirculation is often affected in intermediate uveitis and panuveitis. Here, we examined the extraocular (i.e., systemic) microcirculation in pediatric uveitis cases and healthy controls using nailfold capillaroscopy (NFC).

METHODS

We performed NFC in 119 children with noninfectious uveitis and 25 healthy pediatric controls, and assessed the following parameters: capillary density (number of capillaries/mm), dilated capillaries (apex > 20 µm), avascular area, the presence of microhemorrhages, and capillary morphology. Differences in NFC parameters between cases and controls were calculated using regression analysis after adjusting for age and sex.

RESULTS

The mean (± SD) age of the patient group was 13.7 (± 3) years, with 56% females; 46%, 18%, and 36% of cases presented as anterior uveitis, intermediate uveitis, and panuveitis, respectively, with an overall mean disease duration of 4.7 (± 4.0) years. Compared to the control group, the pediatric uveitis cases had a significantly higher number of dilated capillaries/mm and a higher prevalence of ramified capillaries. Moreover, compared to the control group the intermediate uveitis cases had a significantly higher number of dilated capillaries, whereas the anterior uveitis cases had a lower capillary density and a higher prevalence of ramified capillaries.

CONCLUSIONS

Children with uveitis without systemic disease can present with changes in systemic microcirculation. These changes vary amongst the subtypes of uveitis.

Serum antiretinal antibodies and cytokine profiling in autoimmune retinopathy and their association with clinical outcomes

PURPOSE

Autoimmune retinopathy (AIR) is a group of autoimmune retinal diseases that can cause blindness. The purpose of this study is to investigate the profiles of serum antiretinal antibodies (ARAs) and cytokines and their association with disease diagnosis as well as clinical features in AIR.

METHODS

The patients with presumed para (p) and non-paraneoplastic (np) AIR diagnosis, the patients with retinitis pigmentosa and bilateral uveitis as disease controls, and healthy subjects were prospectively enrolled. Western blotting and Luminex multiple cytokine assay/enzyme linked immunosorbent assay were used to determine the presence of serum ARAs and the concentration of cytokines, respectively. Kruskal-Wallis or chi square test was applied to compare the profiles of ARA and cytokines among various groups. The multilevel mixed-effect regression was used to investigate the association of ARA or cytokines with clinical features.

RESULTS

No significant difference in the band number and subtypes of serum ARAs was found between AIR patients and their controls. AIR patients had higher concentration of serum IFN-ɤ, CXCL9, or CXCL10 than non-AIR controls. A positive correlation was found between increased number of ARAs and elevated TNF-α in np-AIR patients. Elevated pro-inflammatory cytokines or ARA subtypes (antibody against recoverin and α-enolase) were associated with worse retinal functions or anatomy, including visual acuity, visual field, ERG parameters, and central retinal thickness.

CONCLUSIONS

The data of our study demonstrate that detection of serum ARAs has limited value in the diagnosis of AIR. Th1-type cytokines/chemokines or specific ARA subtypes are associated with pathogenesis and disease severity of the AIR.

Bentonite-in hypromellose-poloxamer sol-gel for corneal application of trimetazidine: Study of rheology and ocular anti inflammatory potential

Bentonite is reported to be used for extending ocular drug delivery safely in a controlled manner. Bentonite combined hydroxypropyl methylcellulose (HPMC)-poloxamer based sol-to-gel formulation has been developed for the prophylactic ocular anti-inflammatory effect of trimetazidine after corneal application. HPMC-poloxamer sol formulation was prepared incorporating trimetazidine to bentonite at 1: 2*10^-5 to 1:5*10^-6 ratios using cold method, and investigations were carried out in carrageenan-induced rabbit eye model. Pseudoplastic shear thinning behavior without any yield value and high viscosity at low shear rate were the positive attribute of the tolerability of the sol formulation after ocular instillation. Presence of bentonite nanoplatelets revealed more sustained in vitro release (~79-97 %) and corneal permeation (~79-83 %) over a period of 6 h in comparison to its absence. Prominent acute inflammation has been produced in the carrageenan-induced untreated eye, whereas the absence of ocular inflammation has been noticed in the previously sol-treated eye even after carrageenan injection. HPMC-poloxamer-based formulation exhibited stronger binding affinity (5.13 kcal/mol) in the presence of bentonite rather than its absence (3.99 kcal/mol), resulting in a stable and sustained effect. HPMC-poloxamer in-situ gel of trimetazidine containing bentonite could be utilized for sustained ocular delivery and the control of ophthalmic inflammation prophylactically.

Study of the shared gene signatures of polyarticular juvenile idiopathic arthritis and autoimmune uveitis

Objective

To explore the shared gene signatures and potential molecular mechanisms of polyarticular juvenile idiopathic arthritis (pJIA) and autoimmune uveitis (AU).

Method

The microarray data of pJIA and AU from the Gene Expression Omnibus (GEO) database were downloaded and analyzed. The GEO2R tool was used to identify the shared differentially expressed genes (DEGs) and genes of extracellular proteins were identified among them. Then, weighted gene co-expression network analysis (WGCNA) was used to identify the shared immune-related genes (IRGs) related to pJIA and AU. Moreover, the shared transcription factors (TFs) and microRNAs (miRNAs) in pJIA and AU were acquired by comparing data from HumanTFDB, hTFtarget, GTRD, HMDD, and miRTarBase. Finally, Metascape and g: Profiler were used to carry out function enrichment analyses of previously identified gene sets.

Results

We found 40 up-regulated and 15 down-regulated shared DEGs via GEO2R. Then 24 shared IRGs in positivity-related modules, and 18 shared IRGs in negatively-related modules were found after WGCNA. After that, 3 shared TFs (ARID1A, SMARCC2, SON) were screened. And the constructed TFs-shared DEGs network indicates a central role of ARID1A. Furthermore, hsa-miR-146 was found important in both diseases. The gene sets enrichment analyses suggested up-regulated shared DEGs, TFs targeted shared DEGs, and IRGs positivity-correlated with both diseases mainly enriched in neutrophil degranulation process, IL-4, IL-13, and cytokine signaling pathways. The IRGs negatively correlated with pJIA and AU mainly influence functions of the natural killer cell, cytotoxicity, and glomerular mesangial cell proliferation. The down-regulated shared DEGs and TFs targeted shared DEGs did not show particular functional enrichment.

Conclusion

Our study fully demonstrated the flexibility and complexity of the immune system disorders involved in pJIA and AU. Neutrophil degranulation may be considered the shared pathogenic mechanism, and the roles of ARID1A and MiR-146a are worthy of further in-depth study. Other than that, the importance of periodic inspection of kidney function is also noteworthy.

Ocular immune privilege and retinal pigment epithelial cells

The ocular tissue microenvironment is immune-privileged and uses multiple immunosuppressive mechanisms to prevent the induction of inflammation. The retinal pigment epithelium plays an essential role in ocular immune privilege. In addition to serving as a blood barrier separating the fenestrated choriocapillaris from the retina, the retinal pigment epithelium is a source of immunosuppressive cytokines and membrane-bound negative regulators that modulate the activity of immune cells within the retina. This article reviews the current understanding of how retinal pigment epithelium cells mediate immune regulation, focusing on the changes under pathologic conditions.

Diagnosis and biomarkers for ocular tuberculosis: From the present into the future

Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis (Mtb) and can manifest both pulmonary and extrapulmonary disease, including ocular tuberculosis (OTB). Accurate diagnosis and swift optimal treatment initiation for OTB is faced by many challenges combined with the lack of standardized treatment regimens this results in uncertain OTB outcomes. The purpose of this study is to summarize existing diagnostic approaches and recently discovered biomarkers that may contribute to establishing OTB diagnosis, choice of anti-tubercular therapy (ATT) regimen, and treatment monitoring. The keywords ocular tuberculosis, tuberculosis, Mycobacterium, biomarkers, molecular diagnosis, multi-omics, proteomics, genomics, transcriptomics, metabolomics, T-lymphocytes profiling were searched on PubMed and MEDLINE databases. Articles and books published with at least one of the keywords were included and screened for relevance. There was no time limit for study inclusion. More emphasis was placed on recent publications that contributed new information about the pathogenesis, diagnosis, or treatment of OTB. We excluded abstracts and articles that were not written in the English language. References cited within the identified articles were used to further supplement the search. We found 10 studies evaluating the sensitivity and specificity of interferon-gamma release assay (IGRA), and 6 studies evaluating that of tuberculin skin test (TST) in OTB patients. IGRA (Sp = 71-100%, Se = 36-100%) achieves overall better sensitivity and specificity than TST (Sp = 51.1-85.7%; Se = 70.9-98.5%). For nuclear acid amplification tests (NAAT), we found 7 studies on uniplex polymerase chain reaction (PCR) with different Mtb targets, 7 studies on DNA-based multiplex PCR, 1 study on mRNA-based multiplex PCR, 4 studies on loop-mediated isothermal amplification (LAMP) assay with different Mtb targets, 3 studies on GeneXpert assay, 1 study on GeneXpert Ultra assay and 1 study for MTBDRplus assay for OTB. Specificity is overall improved but sensitivity is highly variable for NAATs (excluding uniplex PCR, Sp = 50-100%; Se = 10.5-98%) as compared to IGRA. We also found 3 transcriptomic studies, 6 proteomic studies, 2 studies on stimulation assays, 1 study on intraocular protein analysis and 1 study on T-lymphocyte profiling in OTB patients. All except 1 study evaluated novel, previously undiscovered biomarkers. Only 1 study has been externally validated by a large independent cohort. Future theranostic marker discovery by a multi-omics approach is essential to deepen pathophysiological understanding of OTB. Combined these might result in swift, optimal and personalized treatment regimens to modulate the heterogeneous mechanisms of OTB. Eventually, these studies could improve the current cumbersome diagnosis and management of OTB.

Bilateral Occlusive Vasculitis Associated with Retinitis Pigmentosa - A Case Report

PURPOSE

To report a case of bilateral occlusive vasculitis associated with retinitis pigmentosa (RP).

METHOD

Case report.

CASE REPORT

A 34-year male presented with blurred vision in left eye (OS) for two weeks and right eye (OD) for one day. He had night blindness for five years. His best corrected visual acuity (BCVA) was OD 20/63 and OS 20/200. Ophthalmoscopy revealed bilateral RP with OD inflammatory central retinal vein occlusion (CRVO) and OS occlusive vasculitis with bilateral macular edema. Presumed intraocular tuberculosis (IOTB) was suspected based on clinical features, positive Mantoux and high-resolution computed tomography chest findings. Oral steroids and antitubercular therapy (ATT) were started. OD received six intravitreal ranibizumab injections. At his 7-month follow-up, BCVA improved, OD 20/40 and OS 20/80.

CONCLUSION

RP rarely can be associated with presumed IOTB. Oral steroids with ATT are helpful; however, in inflammatory CRVO, intravitreal ranibizumab can give good results.

Tear and Plasma Levels of Cytokines in Patients with Uveitis: Search for Active Disease Biomarkers

Uveitis accounts for up to 20% of blindness in Europe, making the development of new non-invasive biomarkers which could help in its management a field of interest. It has been hypothesised that tear levels of cytokines and chemokines could be used as a potential biomarker in patients with anterior uveitis, and this could be correlated with their concentration in plasma. Therefore, we measured twelve cytokines/chemokines in tear and plasma samples of 22 patients diagnosed with active anterior uveitis. Levels of these molecules in tears and plasma were compared and associated with the degree of activity of the uveitis. It is notable that the percentage of tear interleukin (IL)-6 detection was significantly reduced in the inactive phase (p < 0.05). However, the tear concentration in epidermal growth factor (EGF), fractalkine, IL-8, IL-1RA, interferon-inducible protein (IP)-10/CXCL10, vascular endothelial growth factor (VEGF) and IL-6, comparing the active and inactive period, was not statistically different. Apart from the tear VEGF levels, the cytokine/chemokine concentration in tears in the active/inactive phase was statistically different (p < 0.05) from the counterpart levels in plasma. In conclusion, no isolated cytokine/chemokine in the tears has been found in a concentration which could be used as a potential biomarker of disease activity and treatment response.

Analysis of differentially expressed genes in individuals with noninfectious uveitis based on data in the gene expression omnibus database

Noninfectious uveitis (NIU), an intraocular inflammation caused by immune-mediated reactions to eye antigens, is associated with systemic rheumatism and several autoimmune diseases. However, the mechanisms underlying the pathogenesis of uveitis are poorly understood. Therefore, we aimed to identify differentially expressed genes (DEGs) in individuals with NIU and to explore its etiologies using bioinformatics tools. GSE66936 and GSE18781 datasets from the gene expression omnibus (GEO) database were merged and analyzed. Functional enrichment analysis was performed, and protein-protein interaction (PPI) networks were constructed. A total of 89 DEGs were identified. Gene ontology (GO) enrichment analysis identified 21 enriched gene sets. Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis identified four core enriched pathways: antigen processing and expression signaling, natural killer (NK) cell-mediated cytotoxicity signaling, glutathione metabolic signal transduction, and arachidonic acid metabolism pathways. PPI network analysis revealed an active component-target network with 40 nodes and 132 edges, as well as several hub genes, including CD27, LTF, NCR3, SLC4A1, CD69, KLRB1, KIR2DL3, KIR3DL1, and GZMK. The eight potential hub genes may be associated with the risk of developing NIU. NK cell-mediated cytotoxicity signaling might be the key molecular mechanism in the occurrence and development of NIU. Our study provided new insights on NIU, its genetics, molecular pathogenesis and new therapeutic targets.

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).

Therapie der Uveitis mit Biologika

Zielsetzung Ziel dieser Zusammenfassung ist das Vermitteln einer Übersicht zu den verschiedenen Ansatzpunkten, Wirkmechanismen und Indikationen diverser Biologika, die bei der Therapie der nichtinfektiösen Uveitis zum Einsatz kommen.

Material und Methoden Etablierte sowie aktuelle Literatur wurden herangezogen, um die biochemischen und pathophysiologischen Grundlagen sowie eine evidenzbasierte Empfehlung zum Therapieeinsatz verschiedener Biologika bei nichtinfektiöser Uveitis allgemein und bei speziellen Uveitisentitäten darzulegen.

Ergebnisse Für viele Biologika, hier nennenswert TNF-α-Inhibitoren, einige Interleukininhibitoren, Interferone sowie B- und T-Zell-Inhibitoren, liegen mittlerweile gute Daten vor, was ihren Einsatz in der Uveitistherapie mehr als rechtfertigt. Dies trifft insbesondere für den TNF-α-Inhibitor Adalimumab zu, welcher der einzig zugelassene Vertreter für diese Indikation unter den vorgestellten Biologika ist.

Schlussfolgerungen Die Biologika haben die Behandlung der Uveitis revolutioniert und sind aus der aktuellen Therapie der intraokularen Entzündung nicht mehr wegzudenken. Biologika werden bei Ineffektivität oder Unverträglichkeit konventioneller immunsuppressiver Medikamente empfohlen, aber auch bei der Therapie von schwerwiegenden Uveitisformen (z. B. Morbus Behçet). Die TNF-α-Inhibitoren sind die am häufigsten verwendeten Biologika bei Uveitis.

Preventive effects of cristacarpin on experimentally induced uveitis by targeting NF-κB

Cristacarpin is a novel prenylated pterocarpan that reportedly exhibits broad anti-cancer activity by enhancing endoplasmic reticulum stress. However, whether and how cristacarpin affects in-flammatory processes remain largely unknown. In the present study, the anti-inflammatory effect of cristacarpin on lipopolysaccharide (LPS)-induced inflammation was investigated using zebrafish embryos, RAW 264.7 macrophages, and mouse uveitis models. In the non-toxic concentration range (from 20 to 100 μM), cristacarpin suppressed pro-inflammatory mediators such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, while stimulating anti-inflammatory mediators such as IL-4 and IL-10 in LPS-stimulated RAW 264.7 cells and uveitis mouse models. Cristacarpin decreased cell adhesion of macrophages through downregulation of the expression of Ninjurin1 and matrix metalloproteinases. Furthermore, cristacarpin reduced macrophage migration in zebrafish embryos in vivo. Cristacarpin also increased cytosolic levels of inhibitor of nuclear factor-κB and suppressed the nuclear translocation of nuclear factor κ-light-chain-enhancer of activated B cells. Collectively, our results suggest that cristacarpin is a potential therapeutic candidate for developing ocular anti-inflammatory drugs.

Annexin A1 Mimetic Peptide and Piperlongumine: Anti-Inflammatory Profiles in Endotoxin-Induced Uveitis

Uveitis is one of the main causes of blindness worldwide, and therapeutic alternatives are worthy of study. We investigated the effects of piperlongumine (PL) and/or annexin A1 (AnxA1) mimetic peptide Ac2-26 on endotoxin-induced uveitis (EIU). Rats were inoculated with lipopolysaccharide (LPS) and intraperitoneally treated with Ac2-26 (200 µg), PL (200 and 400 µg), or Ac2-26 + PL after 15 min. Then, 24 h after LPS inoculation, leukocytes in aqueous humor, mononuclear cells, AnxA1, formyl peptide receptor (fpr)1, fpr2, and cyclooxygenase (COX)-2 were evaluated in the ocular tissues, along with inflammatory mediators in the blood and macerated supernatant. Decreased leukocyte influx, levels of inflammatory mediators, and COX-2 expression confirmed the anti-inflammatory actions of the peptide and pointed to the protective effects of PL at higher dosage. However, when PL and Ac2-26 were administered in combination, the inflammatory potential was lost. AnxA1 expression was elevated among groups treated with PL or Ac2-26 + PL but reduced after treatment with Ac2-26. Fpr2 expression was increased only in untreated EIU and Ac2-26 groups. The interaction between Ac2-26 and PL negatively affected the anti-inflammatory action of Ac2-26 or PL. We emphasize that the anti-inflammatory effects of PL can be used as a therapeutic strategy to protect against uveitis.

Sympathetic Ophthalmia: Where Do We Currently Stand on Treatment Strategies?

Sympathetic ophthalmia is a rare bilateral diffuse granulomatous panuveitis that usually results from surgical or penetrating trauma to one eye. The symptoms range from impaired near vision to pain, photophobia, and loss of visual acuity. Anterior segment manifestations include bilateral acute uveitis with mutton-fat keratic precipitates and posterior segment findings include vitritis, multifocal neurosensory retinal detachment, choroiditis, optic nerve edema, and Dalen-Fuchs nodules. The diagnosis is clinical. Ancillary investigations include fundus fluorescein angiography, indocyanine green angiography, optical coherence tomography (OCT), ultrasound B scan, and autofluorescence imaging. The management options include corticosteroids (topical and systemic) as the first line along with immunomodulatory therapy started at the presentation of the disease. Recent advances include imaging with OCT-angiography, enhanced depth imaging-OCT (EDI-OCT, choroidal vascular index/CVI), targeting IL-23/IL-17 pathway, and use of biologics for the management of this rare entity. Recent advances in early diagnosis and prompt treatment has led to improved final visual outcomes in both the sympathizing and exciting eye. This review is aimed at giving a comprehensive overview of sympathetic ophthalmia along with a special emphasis on current treatment strategies and recent advances.

Anti-Inflammatory Effect of Tacrolimus/Hydroxypropyl-β-Cyclodextrin Eye Drops in an Endotoxin-Induced Uveitis Model

Background: Uveitis is an infrequent disease which constitutes a major cause of ocular morbidity. Correct management is essential, being corticosteroids its cornerstone. In case of contraindication to corticosteroids or treatment failure, the use of topical tacrolimus (TAC) could be an alternative which has already demonstrated safety and effectiveness in other ocular pathologies. However, TAC eye drops are not marketed, thus their elaboration must be carried out in Hospital Pharmacy Departments (HPDs). Methods: 32 Sprague-Dawley rats were divided into 4 groups of 8 rats each: (a) untreated healthy rats (Healthy); (b) untreated Endotoxin-Induced Uveitis model-rats (EIU); (c) EIU-rats treated with standard treatment of dexamethasone ophthalmic drops (DXM) and (d) EIU-rats treated with TAC-hydroxypropyl-β-cyclodextrin eye drops previously developed by our group (TAC-HPβCD). The mRNA expression levels of IL-6, IL-8, MIP-1α and TNF-α, quantitative analysis of leucocytes in aqueous humor and histological evaluation were performed. Results: TAC-HPβCD eye drops demonstrated to reduce ocular inflammation, expression of IL-6, TNF-α, MIP-1α and leukocyte infiltration in aqueous humor. Conclusions: TAC-HPβCD eye drops showed beneficial effect in EIU model in rats, positioning as an alternative for uveitis treatment in case of corticosteroids resistance or intolerance.

Blocking the inflammasome: A novel approach to treat uveitis

Uveitis is a complex ocular inflammatory disease often accompanied by bacterial or viral infections (infectious uveitis) or underlying autoimmune diseases (non-infectious uveitis). Treatment of the underlying infection along with corticosteroid-mediated suppression of acute inflammation usually resolves infectious uveitis. However, to develop more effective therapies for non-infectious uveitis and to better address acute inflammation in infectious disease, an improved understanding of the underlying inflammatory pathways is needed. In this review, we discuss the disease aetiology, preclinical in vitro and in vivo uveitis models, the role of inflammatory pathways, as well as current and future therapies. In particular, we highlight the involvement of the inflammasome in the development of non-infectious uveitis and how it could be a future target for effective treatment of the disease.

Clinical Profile of COVID-19 Patients Presenting with Uveitis - A Short Case Series

Purpose

To present the clinical features of anterior, intermediate and posterior uveitis in patients with COVID-19 and to increase the awareness of the treating physicians to refer patients with COVID-19 who have eye symptoms for ophthalmic exam, in order to diagnose as early as possible and prevent vision-threatening complications.

Methods

Retrospective observational case reports.

Results

We report three cases of COVID-19 patients who developed uveitis during or after the course of their sickness with COVID-19. All patients underwent a detailed eye examination, relevant history and investigations did not prove any other cause of uveitis.

Conclusion

This report presents novel data on the course of subjects with uveitis during the COVID-19 pandemic. Intermediate and posterior uveitis warrant further evaluation with differential diagnosis supported by laboratory tests due to the association with systemic diseases and risk of permanent vision loss. Iridocyclitis, intermediate, and posterior uveitis treatment should be guided by ophthalmologists, particularly uveitis specialists, when possible.

Signature of Circulating Biomarkers in Recurrent Non-Infectious Anterior Uveitis. Immunomodulatory Effects of DHA-Triglyceride. A Pilot Study

The purpose of this study was to identify circulating biomarkers of recurrent non-infectious anterior uveitis (NIAU), and to address the anti-inflammatory effects of triglyceride containing docosahexaenoic acid (DHA-TG). A prospective multicenter study was conducted in 72 participants distributed into: patients diagnosed with recurrent NIAU in the quiescence stage (uveitis group (UG); n = 36) and healthy controls (control group (CG); n = 36). Each group was randomly assigned to the oral supplementation of one pill/day (+) containing DHA-TG (n = 18) or no-pill condition (-) (n = 17) for three consecutive months. Data from demographics, risk factors, comorbidities, eye complications and therapy were recorded. Blood was collected and processed to determine pro-inflammatory biomarkers by bead-base multiplex assay. Statistical processing with multivariate statistical analysis was performed. The mean age was 50, 12 (10, 31) years. The distribution by gender was 45% males and 55% females. The mean number of uveitis episodes was 5 (2). Higher plasma expression of interleukin (IL)-6 was detected in the UG versus the CG (p = 5 × 10-5). Likewise, significantly higher plasma levels were seen for IL-1β, IL-2, INFγ (p = 10-4), and TNFα (p = 2 × 10-4) in the UG versus the CG. Significantly lower values of the above molecules were found in the +DHA-TG than in the -DHA-TG subgroups, after 3 months of follow-up, TNFα (p = 10-7) and IL-6 (p = 3 × 10-6) being those that most significantly changed. Signatures of circulating inflammatory mediators were obtained in the quiescent stage of recurrent NIAU patients. This 3-month follow-up strongly reinforces that a regular oral administration of DHA-TG reduces the inflammatory load and may potentially supply a prophylaxis-adjunctive mediator for patients at risk of uveitis vision loss.