Systemic contribution of inflammatory mediators to the severity of diabetic and uveitic macular edema.

PURPOSE: To assess whether serum cytokine and growth factor levels are associated with diabetic macular edema (DME) and uveitic macular edema (UME) objective severity. METHODS: Cross-sectional observational study of 81 patients (1 eye/patient) with DME (n=48) and UME (n=33). Macular edema (ME) was defined upon central macular thickness (CMT) ≥ 300 µm on spectral domain optical coherence tomography (OCT). Serum samples were obtained from peripheral blood and IL-1ß, IL-6, IL-8, IL-10, MCP-1, TNF-α, and VEGF levels were determined by Luminex analysis. Main outcome measure was the correlation between mediators' levels and CMT and macular volume (MV) on OCT for ME cases. RESULTS: In DME, IL-6 levels were found to significantly correlate with MV (r=0.324; p=0.028) whereas in UME, IL-8 was significantly associated with both CMT (r=0.401; p=0.021) and MV (r=0.391; p=0.024). IL-8 independently correlated with CMT (ß=177.2; p=0.033) and MV (ß=3.17; p=0.008) in UME multivariate model. CONCLUSION: Peripheral blood IL-6 and IL-8 levels could play a role in the severity of DME and UME, respectively. IL-8 even seems to be independently associated with CMT and MV in UME cases. Such systemic implications could enforce DME and UME personalized diagnostic and therapeutic approaches.

Shear stress modulates inner blood retinal barrier phenotype.

The vascular endothelium responds to the shear stress generated by blood flow and changes function to maintain tissue homeostasis and adapt to injury in pathological conditions. Shear stress in the retinal circulation is altered in patients with retinal vascular diseases, such as diabetic retinopathy. Therefore, we aimed to study the effect of laminar shear stress on barrier properties and on the release of proinflammatory cytokines in human retinal microvascular endothelial cells (HRMEC). HRMEC were cultured in Ibidi flow chambers and exposed to laminar shear stress (0-50 dyn/cm2) for 24-48 h. Tight junction distribution (ZO-1 and claudin-5) and cytokine production were determined by immunofluorescence and ELISA, respectively. The chemotactic effect of conditioned media exposed to shear stress was determined by measuring lymphocyte transmigration in Transwells. We found that cells exposed to moderately low shear stress (1.5 and 5 dyn/cm2) showed enhanced distribution of membrane ZO-1 and claudin-5 and decreased production of the proinflammatory cytokines IL-8, CCL2, and IL-6 compared to static conditions and high shear stress values. Moreover, conditioned media from cells exposed to low shear stress, had the lowest chemotactic effect to recruit lymphocytes compared to conditioned media from cells exposed to static and high shear stress conditions. In conclusion, high shear stress and static flow, associated to impaired retinal circulation, may compromise the inner blood retinal barrier phenotype and barrier function in HRMEC.

Cytokine production in thyroid eye disease: in vitro effects of dexamethasone and IL-6 blockade with tocilizumab.

PURPOSE: To compare IL-6, sIL-6R, and IL-17 secretion in peripheral blood mononuclear cells (PBMCs) cultured with tocilizumab (a humanized monoclonal antibody against the interleukin-6 receptor), dexamethasone, and placebo, obtained from patients with thyroid eye disease (TED) and healthy controls. METHODS: The study was a prospective proof of concept test. We cultured peripheral blood mononuclear cells from TED patients and healthy controls with tocilizumab, dexamethasone, and placebo. IL-6, sIL-6R, and IL-17 levels in supernatants obtained from PBMCs cultures were analyzed by ELISA. RESULTS: We included seventeen patients with thyroid eye disease (12 females and five males). The mean age was 49 years. Both dexamethasone and tocilizumab influenced IL-6 and IL-6Rs levels in patients' group. Supernatants obtained from PBMCs treated with dexamethasone showed 77.2% and 82.8% lower IL-6 levels compared with those cultured with placebo and tocilizumab, respectively. Furthermore, overnight culture of PBMCs with dexamethasone showed significantly lower sIL-6R secretion compared with untreated (33.71%, p = 0.04) and tocilizumab treated (58.21%, p = 0.01) PBMCs. Neither dexamethasone nor tocilizumab affected IL-17 concentrations in PBMCs cultures. CONCLUSIONS: Both dexamethasone and tocilizumab affect the IL-6/sIL-6R system. Specifically, dexamethasone reduces and tocilizumab increases the levels of these cytokines in PBMCs cultures. These results strengthen the molecular rationale for interrogating the efficacy of tocilizumab in steroid-resistant TED, as IL-6 seems to be a common target for both anti-IL-6R antibody and steroids.

TWENTY-FOUR MONTH FOLLOW-UP OF TOCILIZUMAB THERAPY FOR REFRACTORY UVEITIS-RELATED MACULAR EDEMA.

BACKGROUND: To report the 24-month efficacy and safety of the interleukin-6 receptor antagonist tocilizumab (TCZ) for refractory uveitis-related macular edema (ME). METHODS: Data were obtained by standardized chart review. Patients with quiescent uveitis seen at a single tertiary referral center, for whom ME was the principal cause of reduced visual acuity. OUTCOME MEASURES: Central foveal thickness measured by optical coherence tomography; degree of anterior and posterior chamber; inflammation (Standardization of Uveitis Nomenclature Working Group criteria); and visual acuity (Snellen and logarithm of the minimum angle of resolution) were recorded in all patients during TCZ therapy at months 1, 3, 6, 12, 18, and 24. RESULTS: Sixteen eyes from 12 patients (10 women) were included. Mean age was 34.6 years. Mean duration of ME was 13.2 years. All patients achieved 24 months of follow-up and that is the census date for data collection. Before TCZ was commenced, ME was present, and all patients had been previously treated with immunosuppressive therapy and biologic agents. Uveitis diagnoses were juvenile idiopathic arthritis associated, uveitis (n = 6), birdshot chorioretinopathy (n = 2), idiopathic panuveitis (n = 2), sympathetic ophthalmia (n = 1), and ankylosing spondylitis (n = 1). Mean central foveal thickness (95%; confidence interval) was 516 ± 55 µm at baseline, improving to 274 ± 13 at Month 12 (P = 0.0004), and sustained at 274 ± 14 at Month 24 of follow-up (P = 0.00039). Mean logarithm of the minimum angle of resolution best-corrected visual acuity improved from 0.78 ± 0.18 (Snellen 20/120 ± 20/30) at baseline to 0.42 ± 0.17 (20/52 ± 20/30) at Month 12 (P = 0.0001) and 0.40 ± 0.17 (20/50 ± 20/30) at Month 24 of follow-up (P = 0.0002). Tocilizumab therapy was withdrawn in 5 patients with sustained remission at Month 12 but in all, ME relapsed between 1 and 3 months after TCZ discontinuation. Rechallenge of TCZ infusions led to recovery of uveitis control and ME resolution. Two adverse events were reported during two 4-month follow-ups: one Grade 1 neutropenia and one community-acquired pneumonia. CONCLUSION: In this long-term study, TCZ was effective and had a comparable safety profile to published data for TCZ use in other indications, when used for the treatment of refractory uveitis-related ME.

C-reactive protein isoforms differentially affect outer blood-retinal barrier integrity and function.

The retinal pigment epithelium (RPE) forms the outer blood-retinal barrier (oBRB) and is the prime target of early age-related macular degeneration (AMD). C-reactive protein (CRP), a serum biomarker for chronic inflammation and AMD, presents two different isoforms, monomeric (mCRP) and pentameric (pCRP), that may have a different effect on inflammation and barrier function in the RPE. The results reported in this study suggest that mCRP but not pCRP impairs RPE functionality by increasing paracellular permeability and disrupting the tight junction proteins ZO-1 and occludin in RPE cells. Additionally, we evaluated the effect of drugs commonly used in clinical settings on mCRP-induced barrier dysfunction. We found that a corticosteroid (methylprednisolone) and an anti-VEGF agent (bevacizumab) prevented mCRP-induced ARPE-19 barrier disruption and IL-8 production. Furthermore, bevacizumab was also able to revert mCRP-induced IL-8 increase after mCRP stimulation. In conclusion, the presence of mCRP within retinal tissue may lead to disruption of the oBRB, an effect that may be modified in the presence of corticosteroids or anti-VEGF drugs.

Long-term effects of tocilizumab therapy for refractory uveitis-related macular edema.

OBJECTIVE: To report the long-term efficacy and safety of the interleukin-6 receptor antagonist tocilizumab for refractory uveitis-related macular edema (ME). DESIGN: Retrospective cohort study. PARTICIPANTS: Eyes with uveitis seen at a single tertiary referral center for which ME was the principal cause of reduced visual acuity. METHODS: Data were obtained by standardized chart review. MAIN OUTCOME MEASURES: Central foveal thickness (CFT) measured by optical coherence tomography, degree of anterior and posterior chamber inflammation (Standardization of Uveitis Nomenclature Working Group criteria), and visual acuity (logarithm of the minimum angle of resolution [logMAR]) were recorded during tocilizumab therapy at months 1, 3, 6, and 12. RESULTS: Eleven eyes from 7 patients (all women) were included. Mean age was 43.4 years. Mean duration of ME was 14.2 years. Mean follow-up with tocilizumab therapy was 15.2 months (range, 12-18 months). Before tocilizumab therapy, conventional immunosuppressive therapy and 1 or more biologic agents failed in all patients. Uveitis diagnoses were birdshot chorioretinopathy (n = 3), juvenile idiopathic arthritis-associated uveitis (n = 3), and idiopathic panuveitis (n = 1). Mean CFT was 550 ± 226 µm at baseline, 389 ± 112 µm at month 1 (P = 0.007), 317 ± 88 µm at month 3 (P = 0.01), 292 ± 79 µm at month 6 (P = 0.006), and 274 ± 56 µm at month 12 of follow-up (P = 0.002). Mean logMAR best-corrected visual acuity improved from 0.67 ± 0.53 at baseline to 0.4 ± 0.56 at month 12 (P = 0.008). Tocilizumab therapy was withdrawn in 2 patients because of sustained remission at month 12. In both patients, ME relapsed 3 months after tocilizumab withdrawal. Reinitiation of tocilizumab therapy led to good uveitis control and ME resolution. Tocilizumab generally was well tolerated and no serious adverse events were reported. CONCLUSIONS: In this study, tocilizumab was effective in the treatment of refractory inflammatory ME. No serious adverse events were observed.

Proinflammatory cytokines and C-reactive protein in uveitis associated with Behçet's disease.

The aim of the present study was to determine the serum cytokine profile and levels of high sensitivity C-reactive protein (hsCRP) in patients with uveitis associated with Behçet's disease (BD) and to compare them with those obtained from healthy control subjects. We determined the serum concentration of interferon-γ (IFN-γ), interleukin-1ß (IL-1ß), IL-12p70, IL-17A, tumor necrosis factor-α (TNF-α), and hsCRP in 13 patients with active uveitis associated to BD, 24 inactive BD patients, and 20 controls. In a subgroup of 10 active patients, a second serum sample was obtained when the disease was inactive. Cytokine profiles and hsCRP levels were correlated with disease activity, severity, complications, and visual outcome. Levels of IFN-γ and TNF-α were significantly increased in patients with active uveitis associated to BD compared to controls (P < 0.05). IFN-γ, TNF-α, and hsCRP were significantly higher during active uveitis associated to BD compared to inactive disease (P < 0.05). Furthermore, IL-17A was significantly increased in patients with active BD without pharmacological treatment compared to controls (P < 0.05). No significant correlations were found with specific cytokine profiles and disease severity, visual outcome, or complications. In summary, increased serum levels of IFN-γ, TNF-α, IL-17A, and hsCRP were associated with active uveitis associated with BD and might serve as markers of disease activity.

Current and future treatments for Behçet's uveitis: road to remission.

Behçet's disease (BD) is a multisystem inflammatory disorder of uncertain origin, although it remains defined within the spectrum of systemic immune-mediated vasculitic disorders and also represents a spectrum of putative autoimmune disease. Major symptoms include oral aphthous ulcers, genital ulcerations, skin lesions, and ocular lesions. Despite afflicting many systems, ocular complications of BD are some of the more devastating for the patient and their quality of life. Eye involvement, which affects 60-80 % of BD patients, is characterized in its more severe form by posterior or panuveitis including occlusive retinal vasculitis. While pathogenesis of BD remains complex, association with Class I MHC (HLA-B*51) predisposing to inflammation with engagement of the innate-immune system (neutrophils, NK cells), and perpetuated by the adaptive T cell responses against infectious- and/or auto-antigens. Despite the choice of conventional immunosuppressive therapies available, only recently with the advent of biologic therapy has visual prognosis and outcomes been substantially and favorably altered. For example, both interferon-α (IFN-α) and tumour necrosis factor (TNF)-α antagonists deliver promising results and for the first time improve prognosis. With IFN-α therapy, durable remissions of uveitis can be achieved and lead to drug-free remission. Similarly, anti-TNF therapy with infliximab is reported to be rapidly effective in inducing and maintaining remission. Most recently, rising evidence reports on the use of adalimumab, etanercept, and golimumab, while use of anti-interleukin (IL)-1 agents (anakinra, canakinumab, gevokizumab), IL-6 blockers (tocilizumab), and rituximab (depleting anti-CD20 antibody) is also increasing. The aim of this review is to provide evidence for the role of conventional therapies combined with evidence for advantages and disadvantages of biologic therapies in the treatment of ocular BD. Although randomized controlled trials remain sparse, evidence remains strong and enticing that biologic agents are invaluable for the treatment of sight-threatening Behçet's uveitis and makes it an exciting time for Behçet's specialists worldwide.

Biomaterial engineering strategies for modeling the Bruch's membrane in age-related macular degeneration.

Age-related macular degeneration, a multifactorial inflammatory degenerative retinal disease, ranks as the leading cause of blindness in the elderly. Strikingly, there is a scarcity of curative therapies, especially for the atrophic advanced form of age-related macular degeneration, likely due to the lack of models able to fully recapitulate the native structure of the outer blood retinal barrier, the prime target tissue of age-related macular degeneration. Standard in vitro systems rely on 2D monocultures unable to adequately reproduce the structure and function of the outer blood retinal barrier, integrated by the dynamic interaction of the retinal pigment epithelium, the Bruch's membrane, and the underlying choriocapillaris. The Bruch's membrane provides structural and mechanical support and regulates the molecular trafficking in the outer blood retinal barrier, and therefore adequate Bruch's membrane-mimics are key for the development of physiologically relevant models of the outer blood retinal barrier. In the last years, advances in the field of biomaterial engineering have provided novel approaches to mimic the Bruch's membrane from a variety of materials. This review provides a discussion of the integrated properties and function of outer blood retinal barrier components in healthy and age-related macular degeneration status to understand the requirements to adequately fabricate Bruch's membrane biomimetic systems. Then, we discuss novel materials and techniques to fabricate Bruch's membrane-like scaffolds for age-related macular degeneration in vitro modeling, discussing their advantages and challenges with a special focus on the potential of Bruch's membrane-like mimics based on decellularized tissue.

Non-invasive biomarkers for close activity monitoring in birdshot chorioretinitis: Optical coherence tomography angiography and beyond.

PURPOSE: The purpose of the study was to identify non-invasive imaging biomarkers potentially useful for close activity monitoring in birdshot chorioretinitis (BSCR). METHODS: Cross-sectional study of BSCR eyes included as per Levinson's and/or SUN criteria. Eyes were blindly classified into active or inactive groups per clinical inflammatory parameters, ultra-widefield (UWF) pseudocolour images, UWF fluorescein angiography (FA) and macular optical coherence tomography (OCT) cube. Qualitative and quantitative OCT and OCT-angiography (OCT-A) parameters at the fundus, superonasal and inferonasal fields were compared between active and inactive eyes. RESULTS: Thirty consecutive BSCR patients (60 eyes) were analysed. 28 eyes (46.66%) were from women and the overall mean age was 59.7 ± 12.3 years. Active eyes showed an abnormal retinal thickening at inferonasal field (nasal retinal thickness) and a higher averaged thickened retinal index (ATRI) (72.36 active vs. 20.12 inactive, p < 0.0001). A significant moderate correlation was observed between ATRI and FA scores (r = 0.259, p = 0.022). Macular vascular loops were more frequent in the superficial vascular plexus of OCT-A in the active eyes (p = 0.028). The vascular perfusion index tended to be higher in all subfields of active eyes but did not reach statistical significance. CONCLUSION: Multimodal imaging could be key to discerning activity in BSCR eyes. Higher ATRI and the presence of vascular loops in the superficial plexus are potential non-invasive activity biomarkers for the close monitoring of BSCR.

Corrigendum: C-reactive protein isoforms as prognostic markers of COVID-19 severity.

[This corrects the article DOI: 10.3389/fimmu.2022.1105343.].

C-reactive protein-complement factor H axis as a biomarker of activity in early and intermediate age-related macular degeneration.

Purpose: To determine and compare the serum levels of complement Factor H (FH), monomeric C-Reactive Protein (mCRP) and pentameric C-Reactive protein (pCRP) in patients with age-related macular degeneration (AMD) and to correlate them with clinical, structural and functional parameters. Methods: Cross-sectional observational study. One hundred thirty-nine individuals (88 patients and 51 healthy controls) from two referral centers were included and classified into three groups: early or intermediate AMD (n=33), advanced AMD (n=55), and age and sex matched healthy controls (n=51). Serum levels of FH, mCRP, and pCRP were determined and correlated with clinical and imaging parameters. Results: Patients with intermediate AMD presented FH levels significantly lower than controls [186.5 (72.1-931.8) µg/mL vs 415.2 (106.1-1962.2) µg/mL; p=0.039] and FH levels <200 µg/mL were associated with the presence of drusen and pigmentary changes in the fundoscopy (p=0.002). While no differences were observed in pCRP and mCRP levels, and mCRP was only detected in less than 15% of the included participants, women had a significantly higher detection rate of mCRP than men (21.0% vs. 3.8%, p=0.045). In addition, the ratio mCRP/FH (log) was significantly lower in the control group compared to intermediate AMD (p=0.031). Visual acuity (p<0.001), macular volume (p<0.001), and foveal thickness (p=0.034) were significantly lower in the advanced AMD group, and choroidal thickness was significantly lower in advanced AMD compared to early/intermediate AMD (p=0.023). Conclusion: Intermediate AMD was associated in our cohort with decreased serum FH levels together with increased serum mCRP/FH ratio. All these objective serum biomarkers may suggest an underlying systemic inflammatory process in early/intermediate AMD patients.

Lack of association between the protein tyrosine phosphatase non-receptor type 22 R263Q and R620W functional genetic variants and endogenous non-anterior uveitis.

OBJECTIVE: Endogenous uveitis is a major cause of visual loss mediated by the immune system. The protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene encodes a lymphoid-specific phosphatase that plays a key role in T-cell receptor (TCR) signaling. Two independent functional missense single nucleotide polymorphisms (SNPs) located within the PTPN22 gene (R263Q and R620W) have been associated with different autoimmune disorders. We aimed to analyze for the first time the influence of these PTPN22 genetic variants on endogenous non-anterior uveitis susceptibility. METHODS: We performed a case-control study of 217 patients with endogenous non-anterior uveitis and 718 healthy controls from a Spanish population. The PTPN22 polymorphisms (rs33996649 and rs2476601) were genotyped using TaqMan allelic discrimination assays. The allele, genotype, carriers, and allelic combination frequencies were compared between cases and controls with χ(2) analysis or Fisher's exact test. RESULTS: Our results showed no influence of the studied SNPs in the global susceptibility analysis (rs33996649: allelic P- value=0.92, odds ratio=0.97, 95% confidence interval=0.54-1.75; rs2476601: allelic P- value=0.86, odds ratio=1.04, 95% confidence interval=0.68-1.59). Similarly, the allelic combination analysis did not provide additional information. CONCLUSIONS: Our results suggest that the studied polymorphisms of the PTPN22 gene do not play an important role in the pathophysiology of endogenous non-anterior uveitis.

Tocilizumab treatment for refractory uveitis-related cystoid macular edema.

BACKGROUND: This retrospective study investigated the efficacy of tocilizumab (TCZ), a fully humanized antibody that binds both to soluble and membrane bound IL-6 receptors, for the treatment of uveitis-related cystoid macular edema (CME) refractory to immunomodulatory therapy. METHODS: Five refractory patients with uveitis-related CME who received TCZ between January and August 2012 were included. All patients received 8 mg/kg TCZ at 4-week intervals. Data regarding patient demographics, use of immunosuppressive drugs, biologic agents or intravitreal therapies prior to TCZ infusions were collected. Main outcome measure was central foveal thickness (CFT) measured by optical coherence tomography at 6 months. Secondary outcome measures were degree of anterior and posterior chamber inflammation (Standardization of Uveitis Nomenclature Working Group criteria) and visual acuity (logarithm of the minimum angle of resolution [log-MAR]) at month 6. Adverse events (AEs) related to TCZ therapy were also assessed. RESULTS: Eight eyes from five patients (all females) were included. Mean age was 49.4 years (range, 30-68). Mean follow-up was 8.4 months (range, 6-12). Before TCZ, all patients received and failed conventional immunosuppressive therapy and had received at least another biologic agent. Uveitis diagnoses were Birdshot chorioretinopathy (n = 3), juvenile idiopathic arthritis (JIA)-associated uveitis (n = 1), and idiopathic panuveitis (n = 1). Mean evolution of CME was 13.4 years (range, 2-30). Mean baseline CFT (95% confidence interval) was 602 ± 236 µm at baseline, 386 ± 113 µm at month 1 (p = 0.006), 323 ± 103 µm at month 3 (p = 0.026), and 294.5 ± 94.5 µm at month 6 (p = 0.014). Median best-corrected visual acuity (BCVA) improved from 0.66 ± 0.57 at baseline to 0.47 ± 0.62 at month 6 (p = 0.035). After 6 months, an improvement of ≥ 2 lines of BCVA was observed in 50% of eyes (p = 0.028) remained stable in 25% and worsened in none of the patients. Sustained uveitis remission was achieved in all patients. No AEs were reported. CONCLUSIONS: These data suggest that TCZ is effective for treating CME in otherwise treatment-refractory cases of uveitis.

Dexamethasone intravitreal implant for treatment of uveitic persistent cystoid macular edema in vitrectomized patients.

PURPOSE: To evaluate the safety and efficacy of Ozurdex (dexamethasone intravitreal implant) 0.7 mg in the treatment of uveitic macular edema in vitrectomized eyes. METHODS: Data from 13 patients (17 eyes) with persistent uveitic cystoid macular edema and a history of pars plana vitrectomy in the study eyes that were treated with intravitreal injection of 0.7-mg dexamethasone implant were reviewed retrospectively. Main outcome measures were changes in central retinal thickness measured by optical coherence tomography and changes in best-corrected visual acuity. RESULTS: The median age of patients was 61 years (range, 19-81 years). The median duration of uveitic macular edema was 12 months (range, 2-72 months). The mean baseline central retinal thickness (95% confidence interval) was 461.6 µm (403.8-519.4), decreased to 277.2 µm (244.6-309.8) at 4 weeks (P < 0.01), remained low at 349.9 µm (281.8-418.0) at 3 months (P = 0.01), and then reached 394.1 µm (328.3-459.8) at 6 months (P = 0.14). After 3 months, there was a median improvement of 2 lines of best-corrected visual acuity, with 52.9% of eyes gaining 2 lines or more (P < 0.01). At 6 months, there were 5 eyes that maintained the 2 lines gain and none had lost >1 line from baseline (P = 0.03). In 8 eyes (47.1%), reinjection of the implant was performed at a mean of 6.5 months. Ocular hypertension (47.1%), hypotony (11.8%), anterior chamber displacement of the implant (5.9%), and glaucoma, which required filtration surgery (5.9%), were the most common adverse events. Mean follow-up was 9.6 months (range, 6-17 months). CONCLUSION: In this small case series of eyes with limited follow-up, treatment with dexamethasone intravitreal implant injection for uveitic macular edema in vitrectomized eyes was associated with favorable visual outcomes and had an acceptable safety profile.

Clinical pattern of toxoplasmic retinochoroiditis in a Spanish referral center.

BACKGROUND/AIMS: To analyze the clinical pattern of ocular toxoplasmosis in a referral center in Spain. METHODS: The medical records of consecutive patients with ocular toxoplasmosis admitted from a single referral center for uveitis in Barcelona (Spain) were retrospectively analyzed between January 2005 and January 2011. RESULTS: One hundred and thirteen eyes from 113 patients (74 Spanish and 39 South American) with active ocular toxoplasmosis were analyzed with a 12-month follow-up. Final BCVA ≤ 20/200 was found in 30 eyes (26.5%). The most frequent complications were macular edema (16.8%) and epiretinal membrane (11.5%). Anterior chamber cell scores of ≥ 2+ (p = 0.003), vitreous cell scores of ≥ 2+ (p = 0.001), and the presence of cataracts (p = 0.047) or serous retinal detachment (p = 0.008) were more common among the South American than Spanish cohort. Active macular lesions (p < 0.001) with an initial BCVA ≤ 20/200 (p < 0.001) and advanced age (p = 0.019) were predictors for final BCVA ≤ 20/200, whereas female gender (p = 0.021) and an initial BCVA ≤20/200 (p = 0.045) were predictors for ocular complications. Moreover, a BCVA ≤ 20/200 (p < 0.001) and a vitreous cell score of ≥ 2+ (p = 0.045) at the initial examination were predictors of an eventual need for ocular surgery. CONCLUSION: The clinical features of ocular toxoplasmosis in Spanish patients differ from those of South American patients. In general, active macular lesions with an initial BCVA ≤ 20/200 and advanced age were shown to be predictors for final BCVA ≤ 20/200 in our patient cohort.

Proteomic signature of thrombin-activated platelets after in vivo nitric oxide-donor treatment: coordinated inhibition of signaling (phosphatidylinositol 3-kinase-γ, 14-3-3ζ, and growth factor receptor-bound protein 2) and cytoskeleton protein translocation.

OBJECTIVE: Growing insight into the antiplatelet properties of new nitric oxide (NO) donors has expanded their potential use in cardiovascular diseases. As such, we reported that oral administration of a new exogenous NO donor (LA419) induced significant inhibition of platelet deposition on damaged vascular wall without provoking hypotension in an in vivo experimental model. Thrombin is one of the major triggers of platelet deposition and thrombosis on injured vessels; however, the effects of NO on thrombin-induced platelet activation are not fully known. Here, our aim was to investigate the inhibitory effects of exogenous NO administration on the major changes in platelet proteins induced by thrombin. METHODS AND RESULTS: Platelets were obtained from a group of swine orally treated with LA419 (0.9 mg kg(-1)) or placebo for 8 days. Washed platelets were incubated with thrombin (0.4 NIH U/mL). Platelet proteins were then sequentially extracted based on differential solubility and studied by two-dimensional electrophoresis, mass spectrometry (matrix-assisted laser desorption ionization/time of flight), Western blot, and confocal immunofluorescence. NO treatment abrogated thrombin effects on 24 proteins involved in actin assembly, signaling, and metabolic activity. NO treatment prevented thrombin-induced translocation of gelsolin, filamin, 14-3-3ζ, phosphatidylinositol 3-kinase-γ isoform, and growth factor receptor-bound protein 2 (Grb2). CONCLUSION: Our results show that exogenous NO donor treatment renders platelets less sensitive to thrombin activation and inhibits thrombosis by interfering with the platelet shape change machinery.

Bioengineering approaches for modelling retinal pathologies of the outer blood-retinal barrier.

Alterations of the junctional complex of the outer blood-retinal barrier (oBRB), which is integrated by the close interaction of the retinal pigment epithelium, the Bruch's membrane, and the choriocapillaris, contribute to the loss of neuronal signalling and subsequent vision impairment in several retinal inflammatory disorders such as age-related macular degeneration and diabetic retinopathy. Reductionist approaches into the mechanisms that underlie such diseases have been hindered by the absence of adequate in vitro models using human cells to provide the 3D dynamic architecture that enables expression of the in vivo phenotype of the oBRB. Conventional in vitro cell models are based on 2D monolayer cellular cultures, unable to properly recapitulate the complexity of living systems. The main drawbacks of conventional oBRB models also emerge from the cell sourcing, the lack of an appropriate Bruch's membrane analogue, and the lack of choroidal microvasculature with flow. In the last years, the advent of organ-on-a-chip, bioengineering, and stem cell technologies is providing more advanced 3D models with flow, multicellularity, and external control over microenvironmental properties. By incorporating additional biological complexity, organ-on-a-chip devices can mirror physiologically relevant properties of the native tissue while offering additional set ups to model and study disease. In this review we first examine the current understanding of oBRB biology as a functional unit, highlighting the coordinated contribution of the different components to barrier function in health and disease. Then we describe recent advances in the use of pluripotent stem cells-derived retinal cells, Bruch's membrane analogues, and co-culture techniques to recapitulate the oBRB. We finally discuss current advances and challenges of oBRB-on-a-chip technologies for disease modelling.

Antimetabolite Drugs Exhibit Distinctive Immunomodulatory Mechanisms and Effects on the Intestinal Microbiota in Experimental Autoimmune Uveitis.

Purpose: The purpose of this study was to investigate the effect of antimetabolite drugs on T-cell responses and intestinal microbial composition in autoimmune uveitis. Methods: Experimental autoimmune uveitis (EAU) was induced in C57BL/6J mice treated with 0.00625 mg/mL methotrexate (MTX) or 0.625 mg/mL mycophenolate mofetil (MMF) in drinking water for 4 weeks prior to immunization and 2 weeks thereafter. The effector T cell (Teff) and regulatory T cell (Treg) populations were identified using flow cytometry. The 16S rRNA gene sequencing was applied for gut microbiome characterization. DESeq2 analysis was used to discriminate relative abundances of taxa and PLS-DA to integrate cytometric and microbiome data between groups. Results: Both MTX and MMF abrogated uveitis in EAU without clinical signs of toxicity as compared to water-fed controls. MTX reduced Teff and Treg expansion in peripheral tissues and eyes. MTX decreased alpha diversity, increased Akkermansia, and reduced Lachnoclostridium abundances. Conversely, MMF enhanced Tregs in the mesenteric lymph node and the eyes. In parallel, MMF increased the gut alpha diversity, including an increased abundance of Lachnospiraceae NK4A136 group and a decreased abundance of Lachnospiraceae UCG-001. A significant congruent correlation among intestinal microbial changes, T-cell responses, and clinical scores was observed for both antimetabolites. Conclusions: Although MTX and MMF both abrogated uveitis in EAU, they showed different effects on T-cell subsets and the intestinal bacterial composition. This work indicates unique immunomodulation by each drug and is the first to demonstrate potential microbiota-related mechanisms.

C-reactive protein isoforms as prognostic markers of COVID-19 severity.

C-reactive protein (CRP), an active regulator of the innate immune system, has been related to COVID-19 severity. CRP is a dynamic protein undergoing conformational changes upon activation in inflammatory microenvironments between pentameric and monomeric isoforms. Although pentameric CRP is the circulating isoform routinely tested for clinical purposes, monomeric CRP shows more proinflammatory properties. Therefore, we aimed to determine the potential of monomeric CRP in serum as a biomarker of disease severity in COVID-19 patients (admission to intensive care unit [ICU] and/or in-hospital mortality). We retrospectively determined clinical and biological features as well as pentameric and monomeric CRP levels in a cohort of 97 COVID-19 patients within 72h of hospital admission. Patients with severe disease had higher levels of both pentameric and monomeric CRP. However, multivariate analysis showed increased mCRP but not pCRP to be independently associated to disease severity. Notably, mCRP levels higher than 4000 ng/mL (OR: 4.551, 95% CI: 1.329-15.58), together with number of co-morbidities, low lymphocyte count, and procalcitonin levels were independent predictors of disease severity in the multivariate model. Our results show the potential of mCRP levels as a marker of clinical severity in COVID-19 disease.