Gut Pathobiont-Derived Outer Membrane Vesicles Drive Liver Inflammation and Fibrosis in PSC-IBD.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC), often associated with inflammatory bowel disease (IBD), presents a multifactorial etiology involving genetic, immunological, and environmental factors. Gut dysbiosis and bacterial translocation have been implicated in PSC-IBD, yet the precise mechanisms underlying their pathogenesis remain elusive. Here, we describe the role of gut pathobionts in promoting liver inflammation and fibrosis due to the release of bacterial outer membrane vesicles (OMVs). METHODS: Preclinical mouse models in addition to ductal organoids were used to acquire mechanistic data. A proof-of-concept study including serum and liver biopsies of a patient cohort of PSC (n=22), PSC-IBD (n=45) and control individuals (n=27) was performed to detect OMVs in the systemic circulation and liver. RESULTS: In both, preclinical model systems and in human PSC-IBD patients, the translocation of OMVs to the liver correlated with enhanced bacterial sensing and accumulation of the NLRP3 inflammasome. Using ductal organoids, we were able to precisely attribute the pro-inflammatory and pro-fibrogenic properties of OMVs to signaling pathways dependent on TLR4 and NLRP3-GSDMD. The immunostimulatory potential of OMVs could be confirmed in macrophages and hepatic stellate cells. Furthermore, when we administered gut pathobiont-derived OMVs to Mdr2-/- mice, we observed a significant enhancement in liver inflammation and fibrosis. In a translational approach, we substantiated the presence of OMVs in the systemic circulation and hepatic regions of severe fibrosis using a PSC-IBD patient cohort. CONCLUSION: This study demonstrates the contribution of gut pathobionts in releasing OMVs that traverse the mucosal barrier, and thus, promote liver inflammation and fibrosis in PSC-IBD. OMVs might represent a critical new environmental factor that interacts with other disease factors to cause inflammation and thus define potential new targets for fibrosis therapy.

Progression of PROM1-Associated Retinal Degeneration as Determined by Spectral-Domain Optical Coherence Tomography Over a 24-Month Period.

PURPOSE: To evaluate the progression of atrophy as determined by spectral-domain optical coherence tomography (SD-OCT) in patients with molecularly confirmed PROM1-associated retinal degeneration (RD) over a 24-month period. DESIGN: International, multicenter, prospective case series. METHODS: A total of 13 eyes (13 patients) affected with PROM1-associated RD were enrolled at 5 sites and SD-OCT images were obtained at baseline and after 24 months. Loss of mean thickness (MT) and intact area were estimated after semi-automated segmentation for the following individual retinal layers in the central subfield (CS), inner ring, and outer ring of the ETDRS grid: retinal pigment epithelium (RPE), outer segments (OS), inner segments (IS), outer nuclear layer (ONL), inner retina (IR), and total retina (TR). RESULTS: Statistically significant losses of thickness of RPE and TR were detected in the CS and inner ring and of ONL and IS in the outer ring (all P < .05); a statistically significant decrease in the intact area of RPE and IS was observed in the inner ring, and of ONL in the outer ring (all P < .05); the change in MT and the intact area of the other layers showed a trend of decline over an observational period of 24 months. CONCLUSIONS: Significant thickness losses could be detected in outer retinal layers by SD-OCT over a 24-month period in patients with PROM1-associated retinal degeneration. Loss of thickness and/or intact area of such layers may serve as potential endpoints for clinical trials that aim to slow down the disease progression of PROM1-associated retinal degeneration.

Self-Made Sleeve for Chandelier Light Simulation.

PURPOSE: To develop a quick and cost-effective alternative to a chandelier light for vitrectomy. METHODS: The surgical material available in an ophthalmologic operating room was used to create a sleeve for the vitrectomy light probe and tested on 30 consecutive retinal detachment cases for feasibility. RESULTS: A 64 × 5-mm cotton swab stick was cut into the length of the light probe minus the length of the trocar and subsequently pierced by a blunt needle. With this sleeve, the light probe could be safely handled similar to a chandelier light during surgery. CONCLUSION: A sleeve for the light probe can serve as a substitute for a chandelier light during scleral depression in retinal detachment surgery.

CHANGES OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY PARAMETERS AFTER INTERNAL LIMITING MEMBRANE PEELING COMPARED WITH NONPEELING IN EPIRETINAL MEMBRANE SURGERY.

PURPOSE: To prospectively compare microvascular changes of internal limiting membrane (ILM) peeled and nonpeeled eyes in patients with idiopathic epiretinal membranes using optical coherence tomography angiography. METHODS: Forty-two patients with epiretinal membranes underwent vitrectomy with (n = 22) or without ILM peeling (n = 20). The mean superficial capillary plexus foveal avascular zone area change between preoperative and three-month postoperative readings served as the main outcome measure. Secondary outcome parameters included mean changes in superficial capillary plexus parafoveal vessel density, central foveal thickness, retinal volume, and best-corrected visual acuity. RESULTS: Mean superficial capillary plexus foveal avascular zone area change (µm 2 ) was 59 ± 74 in the ILM nonpeeling group compared with -12 ± 86 in the ILM peeling group ( P = 0.007). Similarly, mean superficial capillary plexus parafoveal vessel density change (%) was higher in the ILM nonpeeling group (ILM nonpeeling 4 ± 4, ILM peeling -2 ± 6, P = 0.003). The mean retinal volume reduction was higher in the ILM peeling group, and this difference also reached statistical significance ( P = 0.036). There were no intergroup differences in mean central foveal thickness change and mean best-corrected visual acuity change ( P = 0.409 and P = 0.440, respectively). Epiretinal membrane/ILM separation was achieved in 23 of 51 patients. CONCLUSION: The macular microvasculature demonstrated more remodeling in the ILM nonpeeling group after three months.

Cohort profile: 'Biomarkers of Personalised Medicine' (BioPersMed): a single-centre prospective observational cohort study in Graz/Austria to evaluate novel biomarkers in cardiovascular and metabolic diseases.

PURPOSE: Accumulating evidence points towards a close relationship between cardiovascular, endocrine and metabolic diseases. The BioPersMed Study (Biomarkers of Personalised Medicine) is a single-centre prospective observational cohort study with repetitive examination of participants in 2-year intervals. The aim is to evaluate the predictive impact of various traditional and novel biomarkers of cardiovascular, endocrine and metabolic pathways in asymptomatic individuals at risk for cardiovascular and/or metabolic disease. PARTICIPANTS: Between 2010 and 2016, we recruited 1022 regional individuals into the study. Subjects aged 45 years or older presenting with at least one traditional cardiovascular risk factor or manifest type 2 diabetes mellitus (T2DM) were enrolled. The mean age of the participants was 57±8 years, 55% were female, 18% had T2DM, 33% suffered from arterial hypertension, 15% were smokers, 42% had hyperlipidaemia, and only 26% were at low cardiovascular risk according to the Framingham 'Systematic COronary Risk Evaluation'. FINDINGS TO DATE: Study procedures during screening and follow-up visits included a physical examination and comprehensive cardiovascular, endocrine, metabolic, ocular and laboratory workup with biobanking of blood and urine samples. The variety of assessed biomarkers allows a full phenotyping of individuals at cardiovascular and metabolic risk. Preliminary data from the cohort and relevant biomarker analyses were already used as control population for genomic studies in local and international research cooperation. FUTURE PLANS: Participants will undergo comprehensive cardiovascular, endocrine and metabolic examinations for the next decades and clinical outcomes will be adjudicated prospectively.

Cotinine and cytokine levels in the vitreous body and blood serum of smokers and non-smokers - A pilot study.

Tobacco smoking is a risk factor for many ocular diseases. Of the multiple tobacco smoke compounds nicotine and its main metabolite cotinine are likely agents in disease modulation. The interaction of these compounds with exposed tissue is complex and ranges from proinflammatory to potentially neuroprotective properties. We aimed to determine cotinine and cytokines in the vitreous in smokers and non-smokers in this prospective, cross-sectional study at the Department of Ophthalmology, Medical University Graz, Austria. We included 10 smokers and 10 non-smokers. Vitreous and serum samples were analyzed for cotinine and cytokines. The cytokine analysis was performed with multiplex assay and cotinine was quantified with enzyme-linked immunosorbent assay. Cotinine was detectable in smokers only with a mean of 154.0 ng/ml ± 107.3 ng/ml in the vitreous and of 194.1 ng/ml ± 121.3 ng/ml in the serum. The difference between intraocular and systemic levels was statistically significant. There were no statistically significant differences between the cytokine levels of smokers and non-smokers. However, intravitreal VEGF-A was by trend elevated in smokers and correlated positively with intravitreal cotinine (r = 0.59, p = 0.073). In conclusion cotinine is detectable in the vitreous of smokers and is lower than the serum. There is a trend towards elevation of VEGF-A in the vitreous of smokers.

Vitrectomy for diabetic macular edema and the relevance of external limiting membrane.

PURPOSE: To evaluate the relevance of external limiting membrane (ELM) on the visual and morphological results in eyes with diabetic macular edema (DME) that underwent pars plana vitrectomy (PPV) with epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling. METHODS: Medical records of patients with DME who underwent PPV at our unit between January 2017 and December 2019 were reviewed. We assessed preoperative and postoperative best-corrected visual acuity (BCVA), central macular thickness (CMT) using spectral domain OCT (optical coherence tomography). Exclusion criteria were previous PPV; incomplete data; concomitant diseases including retinal vein occlusion, age-related macular degeneration, uveitis; and a follow-up of less than 12 months. The surgeries were performed using 23- or 27-gauge vitrectomy. The ELM was graded depending on its configuration (grade 0 = intact, grade 1 to 3: disruption of varying extent). RESULTS: Ninety-nine eyes were enrolled. The postoperative follow up averaged 23.7 months. The preoperative and final BCVA averaged 0.71 ± 0.28 and 0.52 ± 0.3 logMAR, respectively (p = 0.002). The CMT averaged 515.2 ± 209.1 µm preoperatively and 327 ± 66.1 µm postoperatively (p = 0.001). Eyes with intact ELM (n = 8) had a significantly better BCVA compared to those with ELM disruption (0.28 ± 0.14 vs. 0.7 ± 0.25 logMAR, p = 0.01). The final CMT was similar among the groups (intact ELM: 317 ± 54.6 µm; ELM disruption: 334 ± 75.2, p = 0.31). CONCLUSIONS: PPV with ERM and ILM peeling is an effective treatment of DME. Eyes with intact ELM preoperatively had a significantly better final visual outcome. To maximize the benefit for patients with DME we recommend early PPV as long as ELM is intact.

Golimumab in juvenile idiopathic arthritis-associated uveitis unresponsive to Adalimumab.

OBJECTIVE: To assess the efficacy of golimumab (GLM) as a treatment option for juvenile idiopathic arthritis (JIA)-associated uveitis refractory to adalimumab (ADA). METHODS: Retrospective single-centre study including patients with JIA receiving GLM for active uveitis after failing ADA. JIA- and uveitis-related data, including intraocular inflammation, best-corrected visual acuity, corticosteroid-sparing potential, and ocular complications were evaluated at start of GLM treatment, at 1 month and 3 months, and every 3 months thereafter during GLM administration. We further investigated the association of response to GLM with primary and secondary failure of ADA treatment. RESULTS: Ten patients were studied, all female (17 affected eyes, mean age 14.3 + 6.7 yrs., mean follow-up 25.2 + 21.7 mos). Two patients were switched to GLM because of primary non-response to ADA. Eight were switched because of loss of response (LOR). In 5 of the latter LOR was associated with neutralizing anti-ADA-antibodies. Response to GLM was observed in all 8 patients with LOR, while the 2 patients with primary non-response to ADA also did not respond to GLM. Three of the 8 responders experienced LOR. At the end of follow-up 4 of the 5 remaining responders had achieved complete response. One had achieved partial response. CONCLUSION: GLM is an efficacious therapeutic option in patients who experience LOR to ADA. Our data indicate that patients without primary response to ADA should be rather switched to a biologic agent with a different mode of action instead of further blocking the TNF-alpha pathway.

Intravitreal Steroid Treatment for Uveitis Associated with Dabrafenib and Trametinib for Metastatic Cutaneous Melanoma.

Purpose: To report a case of bilateral retinal inflammation under long-term therapy with dabrafenib/trametinib for metastatic cutaneous melanoma.Methods: Retrospective chart review.Results: A 59-year-old patient with metastatic cutaneous melanoma diagnosed in 2004 under treatment with dabrafenib/trametinib since 2014 presented to our department with intraretinal hemorrhage and extrafoveal macula edema on the right eye and optic disc swelling on the left eye. The patient did not report visual complaints. After cessation of dabrafenib/trametinib and subconjunctival and intravitreal corticosteroid injections, optic disc swelling on the left eye recovered after 6 months. The macula edema on the right eye was treated with one intravitreal anti-VEGF (vascular endothelial growth factor) injection after encroaching upon the fovea 10 months after initial presentation. The final visual acuity was 20/20 on both eyes.Conclusion: Even after years of treatment with low dose dabrafenib/trametinib, ocular toxicity can develop. Such cases can respond well to intravitreal corticosteroids.

Vascular health assessment with flow-mediated dilatation and retinal image analysis: a pilot study in an adult population from Cape Town.

AIM: Flow-mediated dilatation (FMD) and retinal vascular analysis (RVA) may assist in predicting cardiovascular disease (CVD) but are poorly characterised in South Africa. We recorded baseline FMD and retinal vascular widths in healthy participants, and investigated associations with cardiovascular risk factors. METHODS: Endothelial function (measured with FMD), microvascular structure (evaluated via fundus image analysis) and major CVD risk factors were assessed in 66 participants from Cape Town. RESULTS: Median FMD% was 9.6%, with higher values in females. Mean retinal arteriolar and venular widths were ˜156 and ˜250 µm, respectively. FMD was not associated with CVD risk factors. Hypertension was associated with narrower retinal arterioles and venules. CONCLUSIONS: We report novel baseline FMD data in healthy South African adults from the Western Cape, and show that retinal microvascular calibres are associated with blood pressure. Our baseline FMD and RVA data could serve as a reference for future studies in South Africa.

Vitreous albumin redox state in open-angle glaucoma patients and controls: a pilot study.

PURPOSE: Numerous studies suggest that reactive oxygen species play a crucial role in the development of glaucoma. Since glaucoma patients exhibit posterior vitreous detachment earlier than controls, it has been suggested that reactive oxygen species-increased in glaucoma-also affect the vitreous. In the present study we evaluated the influence of open-angle glaucoma oxidative stress on the redox state of vitreous albumin. METHODS: Albumin redox states of the vitreous and plasma were evaluated in 22 subjects-11 open-angle glaucoma patients and 11 controls-matched for age, gender, and vitreous state. According to the redox state of cysteine-34, albumin can be separated into: human mercaptalbumin (the thiol form), human nonmercaptalbumin1 (a reversible modification due to mild oxidation), and human nonmercaptalbumin2 (an irreversible modification due to severe oxidation). RESULTS: Albumin of both, the open-angle glaucoma group and the control group, was more oxidized in the vitreous compared to plasma. Furthermore, significantly higher human nonmercaptalbumin1 fractions were found in the vitreous of open-angle glaucoma patients compared to controls. No significant differences were found in the plasma albumin fractions between the groups. CONCLUSION: Our results support the hypothesis that oxidative stress plays a crucial role in open-angle glaucoma and that reactive oxygen species in glaucomatous eyes may also affect the vitreous.

Gender differences in albumin and ascorbic acid in the vitreous antioxidant system.

Ascorbic acid is present at high concentrations in the vitreous and plays a central role in vitreous redox chemistry. Albumin is the main protein in the vitreous with antioxidant properties and occurs in different oxidation states, which can be used as redox indicators, but have not been studied in the vitreous. This study, therefore, addressed the vitreous redox state of cysteine-34 of albumin in relation to the ascorbic acid content, which has been suggested to exert a main function in detoxifying reactive oxygen in the vitreous. A total of 58 vitreous samples obtained from patients undergoing vitrectomy were analyzed for (i) human mercaptalbumin (HMA), the reduced thiol form; (ii) human non-mercaptalbumin1 (HNA1), a reversible oxidative modification with a disulfide at cysteine-34; and (iii) human non-mercaptalbumin2 (HNA2), a non-reversibly (highly) oxidized form of albumin; as well as (iv) ascorbic acid concentrations, to study possible relations. In addition, blood samples were taken to compare albumin redox state between plasma and the vitreous. Vitreous albumin showed greater variability in the redox state of cysteine-34 and a shift to the oxidized fractions compared to plasma albumin (P < 0.001). A strong positive relation was observed between the vitreous ascorbic acid concentrations and the reversibly oxidized form, HNA1 (P < 0.001), and a negative relation with the reduced form, HMA. Positive relations between ascorbic acid and HNA1 in the vitreous were stronger in men than in women. In contrast to HMA and HNA1, there was a distinct gender difference noted for the irreversibly oxidized form, HNA2. While males showed a positive relation between the vitreous ascorbic acid concentrations and HNA2, there was no correlation found with HNA2 in females. Our results support the view that ascorbic acid, by decreasing either directly or indirectly the concentrations of molecular oxygen, generates hydrogen peroxide, and that thiols, including HMA, are acting as antioxidants. This study for the first time provides evidence that vitreous albumin can be used as a marker molecule for the appearance of reactive oxygen species in the vitreous of patients undergoing vitrectomy. Moreover, it can be shown that there are gender differences in vitreous ascorbic acid and albumin concentrations as well as in oxidation state of vitreous albumin.

Light-induced changes of the subretinal space of the temporal retina observed via optical coherence tomography.

Photoreceptor function is impaired in many retinal diseases like age-related macular degeneration. Currently, assessment of the photoreceptor function for the early diagnosis and monitoring of these diseases is either subjective, as in visual field testing, requires contact with the eye, like in electroretinography, or relies on research prototypes with acquisition speeds unattained by conventional imaging systems. We developed an objective, noncontact method to monitor photoreceptor function using a standard optical coherence tomography system. This method can be used with various white light sources for stimulation. The technique was applied in five volunteers and detected a decrease of volume of the subretinal space associated with light adaptation processes of the retina.

Drug monitoring in long-term treatment with adalimumab for juvenile idiopathic arthritis-associated uveitis.

OBJECTIVES: Assessing influence of anti-adalimumab (ADA) antibodies (AAA) on serum trough ADA levels and uveitis activity in long-term ADA treatment of juvenile idiopathic arthritis (JIA)-associated uveitis. PATIENTS AND INTERVENTIONS: This prospective observational study included 20 patients from a single centre treated with ADA for active uveitis refractory to conventional disease-modifying antirheumatic drugs. AAA, serum ADA trough levels and uveitis activity were evaluated at regular intervals up to 6 years. RESULTS: AAA were detected in nine patients (45%). Permanent AAA in seven were associated with undetectable ADA trough levels and loss of response (LOR). Transient AAA were detected in four with measurable ADA trough levels and response of uveitis to treatment, followed in two by permanent AAA associated with LOR. Use of concomitant immunosuppression was significantly higher in patients without AAA (p<0.05). CONCLUSIONS: AAA-associated LOR frequently occurs in long-term treatment with ADA for JIA-associated uveitis. Concomitant immunosuppressive therapy significantly reduces the risk of LOR due to AAA.