CRB1-associated retinal degeneration is dependent on bacterial translocation from the gut.

The Crumbs homolog 1 (CRB1) gene is associated with retinal degeneration, most commonly Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP). Here, we demonstrate that murine retinas bearing the Rd8 mutation of Crb1 are characterized by the presence of intralesional bacteria. While normal CRB1 expression was enriched in the apical junctional complexes of retinal pigment epithelium and colonic enterocytes, Crb1 mutations dampened its expression at both sites. Consequent impairment of the outer blood retinal barrier and colonic intestinal epithelial barrier in Rd8 mice led to the translocation of intestinal bacteria from the lower gastrointestinal (GI) tract to the retina, resulting in secondary retinal degeneration. Either the depletion of bacteria systemically or the reintroduction of normal Crb1 expression colonically rescued Rd8-mutation-associated retinal degeneration without reversing the retinal barrier breach. Our data elucidate the pathogenesis of Crb1-mutation-associated retinal degenerations and suggest that antimicrobial agents have the potential to treat this devastating blinding disease.

Systemic immunosuppression depletes peripheral blood regulatory B cells in patients with immune thrombocytopenia.

Regulatory B (Breg) cells are potentially implicated in the pathogenesis of immune thrombocytopenia (ITP). We analysed a prospective cohort of newly diagnosed steroid naïve ITP patients enrolled in the multicentre FLIGHT trial and found that the numbers of Bregs in their peripheral blood were similar to healthy controls. In contrast, Breg numbers were significantly reduced in ITP patients treated with systemic immunosuppression (glucocorticoids or mycophenolate mofetil). We also demonstrate that glucocorticoid treatment impairs Breg interleukin-10 production via an indirect T-cell-mediated mechanism.

Factors Predicting Long-term Outcome and the Need for Surgery in Graves Orbitopathy: Extended Follow-up From the CIRTED Trial.

Graves orbitopathy is both disabling and disfiguring. Medical therapies to reduce inflammation are widely used, but there is limited trial data beyond 18 months of follow-up. METHODS: Three-year follow-up of a subset of the CIRTED trial (N = 68), which randomized patients to receive high-dose oral steroid with azathioprine/placebo and radiotherapy/sham radiotherapy. RESULTS: Data were available at 3 years from 68 of 126 randomized subjects (54%). No additional benefit was seen at 3 years for patients randomized to azathioprine or radiotherapy with regard to a binary clinical composite outcome measure (BCCOM), modified European Group on Graves' Orbitopathy score, or Ophthalmopathy Index.Clinical Activity Score (CAS), Ophthalmopathy Index, and Total Eye Score improved over 3 years (P < .001). However, quality of life at 3 years remained poor. Of 64 individuals with available surgical outcome data, 24 of 64 (37.5%) required surgical intervention. Disease duration of greater than 6 months before treatment was associated with increased need for surgery [odds ratio (OR) 16.8; 95% CI 2.95, 95.0; P = .001]. Higher baseline levels of CAS, Ophthalmopathy Index, and Total Eye Score but not early improvement in CAS were associated with increased requirement for surgery. CONCLUSION: In this long-term follow-up from a clinical trial, 3-year outcomes remained suboptimal with ongoing poor quality of life and high numbers requiring surgery. Importantly, reduction in CAS in the first year, a commonly used surrogate outcome measure, was not associated with improved long-term outcomes.

Epigenetic drug screen identified IOX1 as an inhibitor of Th17-mediated inflammation through targeting TET2.

BACKGROUND: Targeting helper T cells, especially Th17 cells, has become a plausible therapy for many autoimmune diseases. METHODS: Using an in vitro culture system, we screened an epigenetics compound library for inhibitors of IFN-γ and IL-17 expression in murine Th1 and Th17 cultures. FINDINGS: This identified IOX1 as an effective suppressor of IL-17 expression in both murine and human CD4+ T cells. Furthermore, we found that IOX1 suppresses Il17a expression directly by targeting TET2 activity on its promoter in Th17 cells. Using established pre-clinical models of intraocular inflammation, treatment with IOX1 in vivo reduced the migration/infiltration of Th17 cells into the site of inflammation and tissue damage. INTERPRETATION: These results provide evidence of the strong potential for IOX1 as a viable therapy for inflammatory diseases, in particular of the eye. FUNDING: This study was supported by the National Key Research and Development Program of China 2021YFA1101200 (2021YFA1101204) to LW and XW; the National Natural Science Foundation of China 81900844 to XH and 82171041 to LW; the China Postdoctoral Science Foundation 2021M700776 and the Scientific Research Project of Guangdong Provincial Bureau of Traditional Chinese Medicine 20221373 to YZ; and the National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS (National Health Service) Foundation Trust and University College London Institute of Ophthalmology, UK (DAC, LPS, PJPL, MS, ADD and RWJL). The views expressed are those of the authors and not necessarily those of the NIHR or the UK's Department of Health and Social Care.

The Effect of Ophthalmic Surgery for Graves' Orbitopathy on Quality of Life: A Systematic Review and Meta-Analysis.

Background: Graves' orbitopathy (GO) has a profound negative impact on quality of life. Surgery is undertaken to preserve vision, correct diplopia, and improve aesthetics. We sought to quantify the effect of different surgical approaches on quality of life. Methods: Electronic databases Ovid-MEDLINE and EMBASE were used from inception until March 22, 2021, to identify studies assessing quality of life pre- and postsurgical intervention for GO. Two reviewers independently extracted data and performed quality assessments. Random-effects and Bayesian models for meta-analyses were utilized. Results: Ten articles comprising 632 patients with a mean age of 48.4 years (range 16-85 years) were included. All used the Graves' Ophthalmopathy Quality of Life (GO-QOL) questionnaire. For GO-QOL appearance, the pooled standardized mean improvement for patients after surgery was +0.72 (95% confidence interval [CI 0.50-0.94]), I2 = 69% [CI 52-80%]. For GO-QOL visual functioning, the pooled standardized mean difference (SMD) for patients after surgery was +0.41 [CI 0.25-0.58], I2 = 60% [CI 36-74%]. For visual appearance, orbital decompression yielded the greatest improvement (SMD +0.84 [CI 0.54-1.13]) followed by eyelid surgery (SMD +0.38 [CI 0.05-0.70]), while strabismus correction had no significant effect (SMD +0.94 [CI -0.10 to 1.99]). Conversely strabismus correction was associated with the greatest improvement (SMD +1.25 [CI 0.29-2.21]) in visual functioning, outperforming orbital decompression (SMD +0.29 [CI 0.15-0.43]) and eyelid surgery (SMD +0.12 [CI -0.18 to 0.41]). A mean improvement in GO-QOL of greater than 10 points after orbital decompression surgery was achieved in 12/14 (86%) patient groups for appearance and 5/14 (36%) patient groups for visual functioning. A mean improvement of greater than 6 points was achieved in 5 of 6 (83%) patient groups for strabismus surgery for both appearance and visual functioning. A mean improvement of greater than 6 points after eyelid surgery was achieved in 2/3 (67%) patient groups and 0/3 patient groups for visual appearance and functioning, respectively. Conclusion: Ophthalmic surgery results in substantial improvements in quality of life in patients with GO, with greater perceived effects on appearance than visual function. Orbital decompression has particular impact on visual appearance; strabismus surgery may benefit both visual appearance and function equally, whereas eyelid surgery benefits appearance alone.

Ibrutinib-related uveitis: A report of two severe cases.

INTRODUCTION: Ibrutinib is a small-molecule drug approved for the treatment of haematological disorders and is known to be associated with visual disturbances, but uveitis has not yet been reported as an adverse effect of this medication. We present two cases of ibrutinib-associated severe uveitis in patients with chronic lymphocytic leukaemia. CASE DESCRIPTION: Our first case is a 65-year-old woman who presented with acute onset of bilateral fibrinous anterior uveitis 1 day after starting ibrutinib. Her vision was hand movements in the right eye and 20/120 in the left with hyperaemic discs and subretinal fluid. Ibrutinib was stopped and she experienced a significant improvement under local and oral steroid treatment. The second case is a 64-year-old male with subacute onset of bilateral hypertensive anterior uveitis with pupillary seclusion and right eye hyphaema. He was on ibrutinib for the past 9 months. His vision at presentation was 20/80 and 20/60 for the right and left eye, respectively. He responded poorly to local steroid treatment until ibrutinib was stopped due to cardiac side-effects, after which his uveitis resolved and treatment was stopped. CONCLUSION: The temporal association between changes in ibrutinib treatment and our patients' ocular inflammation suggests a causative link. Ibrutinib increases Th1-based immune responses which is proposed as a mechanism for drug-induced uveitis. Its antiplatelet effect may explain the fibrinous nature of the inflammation and hyphaema.

Identification of an intraocular microbiota.

The current dogma in ophthalmology and vision research presumes the intraocular environment to be sterile. However, recent evidence of intestinal bacterial translocation into the bloodstream and many other internal organs including the eyes, found in healthy and diseased animal models, suggests that the intraocular cavity may also be inhabited by a microbial community. Here, we tested intraocular samples from over 1000 human eyes. Using quantitative PCR, negative staining transmission electron microscopy, direct culture, and high-throughput sequencing technologies, we demonstrated the presence of intraocular bacteria. The possibility that the microbiome from these low-biomass communities could be a contamination from other tissues and reagents was carefully evaluated and excluded. We also provide preliminary evidence that a disease-specific microbial signature characterized the intraocular environment of patients with age-related macular degeneration and glaucoma, suggesting that either spontaneous or pathogenic bacterial translocation may be associated with these common sight-threatening conditions. Furthermore, we revealed the presence of an intraocular microbiome in normal eyes from non-human mammals and demonstrated that this varied across species (rat, rabbit, pig, and macaque) and was established after birth. These findings represent the first-ever evidence of intraocular microbiota in humans.

Glucocorticoid treatment in patients with newly diagnosed immune thrombocytopenia switches CD14++ CD16+ intermediate monocytes from a pro-inflammatory to an anti-inflammatory phenotype.

Immune thrombocytopenia (ITP) is thought to result from an aberrant adaptive autoimmune response, involving autoantibodies, B and T lymphocytes, directed at platelets and megakaryocytes. Previous reports have demonstrated skewed CD4+ T-helper subset distribution and enhanced production of pro-inflammatory cytokines such as interleukin 17A and interferon gamma. The role of monocytes (MCs) in ITP is less widely described, but innate immune cells have a role in shaping CD4+ T-cell phenotypes. Glucocorticoids (GCs) are commonly used for first-line ITP treatment and modulate a broad range of immune cells including T cells and MCs. Using multiparameter flow cytometry analysis, we demonstrate the expansion of intermediate MCs (CD14++ CD16+ ) in untreated patients with newly diagnosed ITP, with these cells displaying a pro-inflammatory phenotype, characterised by enhanced expression of CD64 and CD80. After 2 weeks of prednisolone treatment (1 mg/kg daily), the proportion of intermediate MCs reduced, with enhanced expression of the anti-inflammatory markers CD206 and CD163. Healthy control MCs were distinctly different than MCs from patients with ITP before and after GC treatment. Furthermore, the GC-induced phenotype was not observed in patients with chronic ITP receiving thrombopoietin receptor agonists. These data suggest a role of MCs in ITP pathogenesis and clinical response to GC therapy.

IL-10 and IL-17 expression by CD4+ T cells is altered in corticosteroid refractory immune thrombocytopenia (ITP).

BACKGROUND: Corticosteroids remain the first-line treatment for patients with immune thrombocytopenia (ITP). However, 20% to 30% of patients do not respond to treatment at tolerable doses. This variation in corticosteroid efficacy is replicated in other autoimmune diseases and may have an adaptive immune basis. OBJECTIVE: To test the hypothesis that CD4+ T-cell responses to corticosteroids are different in patients with clinically defined corticosteroid refractory ITP. METHODS: In this prospective cohort study, CD4+ T cells from patients with ITP were cultured in the presence or absence of dexamethasone (Dex). Intracellular cytokine expression was then quantified by flow cytometry and compared with patients' clinical response to corticosteroid treatment. A control cohort of patients with autoimmune uveitis was also studied to evaluate whether our findings were limited to ITP or are potentially generalizable across autoimmune diseases. RESULTS: The ratio of interleukin (IL)-10 to IL-17 expression following CD4+ T cell culture with Dex was able to discriminate between ITP patients with a clinically defined complete (n = 33), partial (n = 12) or nonresponse (n = 11) to corticosteroid treatment (P = .002). These findings were replicated in patients with autoimmune uveitis (complete response n = 14, nonresponse n = 22; P = .01). CONCLUSIONS: There is a relative abrogation of IL-10 and persistence of IL-17 expression in the CD4+ T cells of patients who clinically fail corticosteroid therapy. This observation has potential to inform both our mechanistic understanding of the action of corticosteroids in the treatment of ITP, and as a biomarker for steroid refractory disease, with potential application across a range of hematological and nonhematological conditions.

Tocilizumab in patients with anti-TNF refractory juvenile idiopathic arthritis-associated uveitis (APTITUDE): a multicentre, single-arm, phase 2 trial.

BACKGROUND: Uveitis associated with juvenile idiopathic arthritis is a cause of major ocular morbidity. A substantial proportion of children are refractory to systemic methotrexate and TNF inhibitors. Our aim was to study the safety and efficacy of tocilizumab in children with juvenile idiopathic arthritis-associated uveitis refractory to both methotrexate and TNF inhibitors. METHODS: This multicentre, single-arm, phase 2 trial was done following a Simon's two-stage design at seven tertiary hospital sites in the UK. Patients aged 2-18 years with active juvenile idiopathic arthritis-associated uveitis were eligible. All patients had been on a stable dose of methotrexate for at least 12 weeks and had not responded to treatment with a TNF inhibitor. Patients weighing 30 kg or more were treated with 162 mg subcutaneous tocilizumab every 2 weeks for 24 weeks, and participants weighing less than 30 kg were treated with 162 mg every 3 weeks for 24 weeks. The primary outcome was treatment response defined as a two-step decrease, or decrease to zero, from baseline in the level of inflammation (anterior chamber cells) at week 12, per the standardisation of uveitis nomenclature criteria. A phase 3 trial would be justified if more than seven patients responded to treatment. An interim analysis was planned to assess whether the trial would be stopped for futility, with futility defined as two or fewer treatment responses among ten participants. Adverse events were collected up to 30 calendar days after treatment cessation. The primary analysis was done in the intention-to-treat population and the safety analysis was done in all patients who started the treatment. This trial is registered with the International Standard Randomised Controlled Trial Number registry (ISRCTN95363507) and EU Clinical Trials Register (EudraCT 2015-001323-23). FINDINGS: 22 participants were enrolled to the trial between Dec 3, 2015, and March 9, 2018, and 21 participants received treatment. One participant was found to be ineligible immediately after enrolment and was therefore withdrawn. Seven of 21 (median unbiased estimate of proportion 34% [95% CI 25-57]) responded to treatment (p=0·11). Safety results were consistent with the known safety profile of tocilizumab. INTERPRETATION: The primary endpoint was not met, and thus the results do not support a phase 3 trial of tocilizumab in patients with juvenile idiopathic arthritis-associated uveitis. Importantly, data on the use of tocilizumab in clinical practice is now captured in national registries. Despite this trial not meeting the threshold required to justify a larger phase 3 trial, several patients responded to treatment; as such, tocilzumab might still be a therapeutic option in some children with uveitis refractory to anti-TNF drugs, given the absence of other treatment options. FUNDING: Versus Arthritis and the National Institute for Health Research Clinical Research Network: Children.

Intravenous indocyanine green dye is insufficient for robust immune cell labelling in the human retina.

It is not currently possible to reliably visualise and track immune cells in the human central nervous system or eye. Previous work demonstrated that indocyanine green (ICG) dye could label immune cells and be imaged after a delay during disease in the mouse retina. We report a pilot study investigating if ICG can similarly label immune cells within the human retina. Twelve adult participants receiving ICG angiography as part of routine standard of care were recruited. Baseline retinal images were obtained prior to ICG administration then repeated over a period ranging from 2 hours to 9 days. Matched peripheral blood samples were obtained to examine systemic immune cell labelling and activation from ICG by flow cytometry with human macrophage cultures as positive controls. Differences between the delayed near infrared ICG imaging and 488 nm autofluorescence was observed across pathologies, likely arising from the retinal pigment epithelium (RPE). Only one subject demonstrated ICG signal on peripheral blood myeloid cells and only three distinct cell-sized signals appeared over time within the retina of three participants. No significant increase in immune cell activation markers were detected after ICG administration. ICG accumulated in the endosomes of macrophage cultures and was detectable above a minimum concentration, suggesting cell labelling is possible. ICG can label RPE and may be used as an additional biomarker for RPE health across a range of retinal disorders. Standard clinical doses of intravenous ICG do not lead to robust immune cell labelling in human blood or retina and further optimisation in dose and route are required.

New insights into the pathogenesis and nonsurgical management of Graves orbitopathy.

Graves orbitopathy, also known as thyroid eye disease or thyroid-associated orbitopathy, is visually disabling, cosmetically disfiguring and has a substantial negative impact on a patient's quality of life. There is increasing awareness of the need for early diagnosis and rapid specialist input from endocrinologists and ophthalmologists. Glucocorticoids are the mainstay of treatment; however, recurrence occurs frequently once these are withdrawn. Furthermore, in >60% of cases, normal orbital anatomy is not restored, and skilled rehabilitative surgery is required. Clinical trials have shown that considerable benefit can be derived from the addition of antiproliferative agents (such as mycophenolate or azathioprine) in preventing deterioration after steroid cessation. In addition, targeted biologic therapies have shown promise, including teprotumumab, which reduces proptosis, rituximab (anti-CD20), which reduces inflammation, and tocilizumab, which potentially benefits both of these parameters. Other strategies such as orbital radiotherapy have had their widespread role in combination therapy called into question. The pathophysiology of Graves orbitopathy has also been revised with identification of new potential therapeutic targets. In this Review we provide an up-to-date overview of the field, outline the optimal management of Graves orbitopathy and summarize the research developments in this area to highlight future research questions and direct future clinical trials.

Ex Vivo T Cell Cytokine Expression Predicts Survival in Patients with Severe Alcoholic Hepatitis.

Alcoholic hepatitis (AH) is an acute inflammatory liver condition with high early mortality rate. Steroids improve short-term survival but nonresponders have the worst outcomes. There is a clinical need to identify these high-risk individuals at the time of presentation. T cells are implicated in AH and steroid responsiveness. We measured ;ex vivo T cell cytokine expression as a candidate biomarker of outcomes in patients with AH. Consecutive patients (bilirubin >80 µmol/L and ratio of aspartate aminotransferase to alanine aminotransferase >1.5 who were heavy alcohol consumers with discriminant function [DF] ≥32), were recruited from University Hospitals Plymouth NHS Trust. T cells were obtained and stimulated ;ex vivo. Cytokine expression levels were determined by flow cytometry and protein multiplex analysis. Twenty-three patients were recruited (10 male; median age 51 years; baseline DF 67; 30% 90-day mortality). Compared to T cells from nonsurvivors at day 90, T cells from survivors had higher baseline baseline intracellular interleukin (IL)-10:IL-17A ratio (0.43 vs 1.20, p=0.02). Multiplex protein analysis identified interferon γ (IFNγ) and tumor necrosis factor-α (TNF-α) as independent predictors of 90-day mortality (p=0.04, p=0.01, respectively). The ratio of IFNγ to TNF-α was predictive of 90-day mortality (1.4 vs 0.2, p=0.03). These data demonstrate the potential utility of T cell cytokine release assays performed on pretreatment blood samples as biomarkers of survival in patients with severe AH. Our key findings were that intracellular IL-10:IL-17A and IFNγ:TNF-α in culture supernatants were predictors of 90-day mortality. This offers the promise of developing T cell-based diagnostic tools for risk stratification.

Intermediate Monocytes in Acute Alcoholic Hepatitis Are Functionally Activated and Induce IL-17 Expression in CD4+ T Cells.

In humans, the three main circulating monocyte subsets are defined by their relative cell surface expression of CD14 and CD16. They are all challenging to study because their characteristics are strongly context specific, and this has led to a range of conflicting reports about their function, which is especially so for CD14++CD16+ (intermediate) monocytes. Ex vivo cultures are also often confounded by the concomitant use of immunosuppressive drugs. We therefore sought to characterize the phenotype and function of intermediate monocytes in the setting of acute inflammation prior to treatment in a cohort of 41 patients with acute alcoholic hepatitis (AH). Circulating intermediate monocytes were enriched in patients with AH and had an activated phenotype with enhanced expression of CCR2 and CD206 compared with healthy controls. Proinflammatory cytokine expression, including IL-1ß and IL-23, was also higher than in healthy controls, but both classical (CD14++CD16-) and intermediate monocytes in AH were refractory to TLR stimulation. Compared with healthy controls, both AH monocyte subsets had greater phagocytic capacity, enhanced ability to drive memory T cell proliferation in coculture, and skewed CD4+ T cells to express an increased ratio of IL-17/IFN-γ. Furthermore, liver tissue from AH patients demonstrated an enrichment of monocytes including the intermediate subset compared with controls. These data demonstrate that intermediate monocytes are expanded, functionally activated, induce CD4+ T cell IL-17 expression, and are enriched in the liver of patients with AH.

Modelling Macular Edema: The Effect of IL-6 and IL-6R Blockade on Human Blood-Retinal Barrier Integrity In Vitro.

PURPOSE: Macular edema (ME) is a leading cause of visual loss in a range of retinal diseases and despite the use of antivascular endothelial growth factor (anti-VEGF) agents, its successful treatment remains a major clinical challenge. Based on the indirect clinical evidence that interleukin-6 (IL-6) is a key additional candidate mediator of ME, we interrogated the effect of IL-6 on blood-retinal barrier (BRB) integrity in vitro. METHODS: Human retinal pigment epithelial cell (ARPE-19) and human retinal microvascular endothelial cell (HRMEC) monolayers were used to mimic the outer and inner BRB, respectively. Their paracellular permeability was assessed by measuring the passive permeation of 40 kDa fluorescein isothiocyanate (FITC)-dextran across confluent cells in the presence of IL-6. Transendothelial/epithelial electrical resistance (TEER) then was measured and the distribution of the tight junction protein ZO-1 was assessed by immunofluorescence using confocal microscopy. RESULTS: Treatment with IL-6 for 48 hours significantly increased the diffusion rate of FITC-dextran, decreased TEER, and disrupted the distribution of ZO-1 in ARPE-19 cells, which constitutively express the IL-6 transmembrane receptor, and this was reversed with IL-6R blockade. In contrast, IL-6 did not affect the paracellular permeability, TEER, or ZO-1 distribution in HRMECs. CONCLUSIONS: These in vitro data support the hypothesis that IL-6 reversibly disrupts the integrity of ARPE-19 cells, but it does not affect HRMECs. TRANSLATIONAL RELEVANCE: IL-6 is a candidate therapeutic target in the treatment of outer BRB driven ME.

The DNA Methylation Inhibitor Zebularine Controls CD4+ T Cell Mediated Intraocular Inflammation.

CD4+ T cell mediated uveitis is conventionally treated with systemic immunosuppressive agents, including corticosteroids and biologics targeting key inflammatory cytokines. However, their long-term utility is limited due to various side effects. Here, we investigated whether DNA methylation inhibitor zebularine can target CD4+ T cells and control intraocular inflammation. Our results showed that zebularine restrained the expression of inflammatory cytokines IFN-γ and IL-17 in both human and murine CD4+ T cells in vitro. Importantly, it also significantly alleviated intraocular inflammation and retinal tissue damage in the murine experimental autoimmune uveitis (EAU) model in vivo, suggesting that the DNA methylation inhibitor zebularine is a candidate new therapeutic agent for uveitis.

Human Th17 cells produce a soluble mediator that increases podocyte motility via signaling pathways that mimic PAR-1 activation.

The specific pathogenesis of idiopathic nephrotic syndrome (NS) is poorly understood, and the role of immune mediators remains contentious. However, there is good evidence for the role of a circulating factor, and we recently postulated circulating proteases as candidate factors. Immunosuppressive therapy with glucocorticoids (GCs) and T cell inhibitors are widely used in the clinical treatment of NS. Given that T helper (CD4+) cells expressing IL-17A (so-called Th17 cells) have recently been reported to be resistant to GC treatment, and GC resistance remains a major challenge in the management of NS, we hypothesized that Th17 cells produce a circulating factor that is capable of signaling to the podocyte and inducing deleterious phenotypic changes. To test this, we generated human Th17 cells from healthy volunteers and added the supernatants from these T cell cultures to conditionally immortalized human podocytes in vitro. This demonstrated that podocytes treated with Th17 cell culture supernatant, as well as with patient disease plasma, showed significant stimulation of JNK and p38 MAPK pathways and an increase in motility, which was blocked using a JNK inhibitor. We have previously shown that nephrotic plasma elicits a podocyte response via protease-activated receptor-1 (PAR-1). Stimulation of PAR-1 in podocytes elicited the same signaling response as Th17 cell culture supernatant treatment. Equally, protease inhibitors with Th17 cell culture treatment blocked the signaling response. This was not replicated by the reagents added to Th17 cell cultures or by IL-17A. Hence, we conclude that an undefined soluble mediator produced by Th17 cells mimics the deleterious effect of PAR-1 activation in vitro. Given the association between pathogenic subsets of Th17 cells and GC resistance, these observations have potential therapeutic relevance for patients with NS.

Glucocorticoid Receptor-α and MKP-1 as Candidate Biomarkers for Treatment Response and Disease Activity in Vogt-Koyanagi-Harada Disease.

PURPOSE: To investigate the potential of utilizing the expression of genes for glucocorticoid receptor (GR) and mitogen-activated protein kinase phosphatase-1 (MKP-1) as biomarkers of corticosteroid (CS) refractoriness and disease activity in patients with Vogt-Koyanagi-Harada (VKH) disease. DESIGN: Prospective cohort study. METHODS: Twenty VKH patients receiving their first cycle of CS treatment in the absence of additional systemic immunosuppressive therapy and a control group of fifteen healthy volunteers were recruited from the University of Chile (Santiago, Chile) and US National Institutes of Health (Bethesda, United States). Intraocular inflammation was clinically quantified at enrolment and all follow-up visits. CS refractoriness was defined as an ocular reactivation of VKH upon CS withdrawal at a daily oral prednisone dose of 10 mg or more. Quantitative Reverse transcription polymerase chain reaction (qRT-PCR) was performed to measure the mRNA levels of the alpha (α) and beta (ß) isoforms of GR and MKP-1 in peripheral blood mononuclear cells (PBMC) after in vitro stimulation with either anti-CD3/anti-CD28 antibodies, lipopolysaccharide (LPS), or phytohemagglutinin (PHA), in the presence or absence of dexamethasone (Dex). RESULTS: After 6 hours of stimulation in the presence of Dex, PBMC from CS-refractory VKH patients had an impaired elevation in GRα expression (P = .03). Furthermore, inactive patients showed a significant Dex-induced upregulation of MKP-1 (P = .005). CONCLUSIONS: In this pilot study, the expression of GR isoforms and MKP-1 corresponded with patients' clinical response to systemic CS treatment and disease activity, respectively. Hence, these candidate biomarkers have potential clinical utility in the early identification of CS refractoriness and subclinical inflammation in patients with VKH disease.