Jonas Kuiper

Intraocular Interleukin-17 and Proinflammatory Cytokines in HLA-A29–Associated Birdshot Chorioretinopathy

PURPOSE To determine the levels of 23 immune mediators in paired aqueous humor (AqH) and serum samples from patients with birdshot chorioretinopathy (BSCR). DESIGN Single-centre case-control study. METHODS A multiplex immunoassay was used to determine the levels of 23 immune mediators (T-cell, proinflammatory, and vascular-active mediators) in paired AqH and serum of 16 BSCR patients. The AqH of 11 age-related cataract controls served as controls. RESULTS AqH levels of the T-cell mediators interleukin (IL)-2 (P=.044) and IL-17 (P=.039) and proinflammatory mediators IL-1β (P=.032), IL-6 (P=.034), and tumor necrosis factor α (P=.041) were elevated compared with that of age-related cataract controls. The elevated intraocular levels of IL-1β, IL-17, and tumor necrosis factor α in BSCR samples were higher than their concurrent serum levels. A significant positive correlation of intraocular mediators was noted between IL-17 and both IL-2 (r=0.744; P<.0001) and IL-23 (r=0.921; P<.0001) and between IL-2 and IL-23 (r=0.776; P<.0001). AqH levels of vascular-active mediators were not distinct between the groups. CONCLUSIONS BSCR patients have elevated intraocular levels of proinflammatory and T cell-associated cytokines. Our results suggest the novel pathogenic concept that BSCR is an autoimmune inflammatory disease restricted to the eye and associated with elevated IL-17.

A genome-wide association study identifies a functional ERAP2 haplotype associated with birdshot chorioretinopathy

Birdshot chorioretinopathy (BSCR) is a rare form of autoimmune uveitis that can lead to severe visual impairment. Intriguingly, >95% of cases carry the HLA-A29 allele, which defines the strongest documented HLA association for a human disease. We have conducted a genome-wide association study in 96 Dutch and 27 Spanish cases, and 398 unrelated Dutch and 380 Spanish controls. Fine-mapping the primary MHC association through high-resolution imputation at classical HLA loci, identified HLA-A*29:02 as the principal MHC association (odds ratio (OR) = 157.5, 95% CI 91.6-272.6, P = 6.6 × 10(-74)). We also identified two novel susceptibility loci at 5q15 near ERAP2 (rs7705093; OR = 2.3, 95% CI 1.7-3.1, for the T allele, P = 8.6 × 10(-8)) and at 14q32.31 in the TECPR2 gene (rs150571175; OR = 6.1, 95% CI 3.2-11.7, for the A allele, P = 3.2 × 10(-8)). The association near ERAP2 was confirmed in an independent British case-control samples (combined meta-analysis P = 1.7 × 10(-9)). Functional analyses revealed that the risk allele of the polymorphism near ERAP2 is strongly associated with high mRNA and protein expression of ERAP2 in B cells. This study further defined an extremely strong MHC risk component in BSCR, and detected evidence for a novel disease mechanism that affects peptide processing in the endoplasmic reticulum.

The immunopathogenesis of birdshot chorioretinopathy; a bird of many feathers

Birdshot chorioretinopathy (BSCR) is a bilateral chronic intraocular inflammation or posterior uveitis that preferentially affects middle-aged Caucasians. BSCR is characterized by distinctive multiple choroidal hypopigmented lesions in combination with retinal vasculitis and vitritis, and the extraordinary feature that virtually all patients are HLA-A29 positive. Its pathophysiology is still poorly understood. BSCR is the strongest documented association between HLA and disease in humans, which makes it an excellent model for studying the underlying immuno-genetic mechanisms of HLA class I-associated diseases. Although the association with HLA-A29 suggests that it is directly involved in the presentation of peptide antigens to T cells, the exact contribution of HLA-A29 to the pathophysiology of BSCR remains enigmatic. This article revisits the HLA-A29 peptidome using insights from recent studies and discusses why HLA-A29 can be considered a canonical antigen presenting molecule. The first genome-wide association study facilitated novel concepts into a disease mechanism beyond HLA-A29 that includes strong genetic predisposition for the ERAP2 gene that affects antigen processing for HLA class I. Furthermore, patients manifest with pro-inflammatory cytokine profiles and pathogenic T cell subsets that are associated with IL-17-linked inflammation. We are beginning to understand that the underlying biology of BSCR comprises various pathologic aspects branched into multiple molecular pathways. We propose to employ Systems Medicine to reveal their dynamic interplay for a holistic view of the immunopathology of this intriguing archetypal HLA class I-associated disease.

Cytokine Expression in Keratoconus and its Corneal Microenvironment: A Systematic Review

Keratoconus (KC) is a progressive corneal ecstasia characterized by thinning and weakening of the cornea that leads to a cone-like appearance, scarring, and decreased vision. Despite the well-described clinical signs, the cause of KC is unknown. Nevertheless, various genes, proteinases, and environmental factors (eye-rubbing, contact lens wear, tear film composition) have been implicated in its etiology. Although classically defined as a predominantly degenerative disease, with mechanically induced trauma accelerating its course, accumulating evidence suggests a pivotal role for inflammation in the pathophysiology of KC. Several reports have linked various inflammatory mediators (cytokines) with KC, but with contradictory findings. The methods and materials used in these studies vary considerably and warrant critical evaluation to decipher the role of inflammatory mediators in KC. We performed a systematic review of current literature on cytokine expression studies in KC and discuss critical soluble and cellular inflammatory mediators that are implicated in its pathogenesis.

Detection of choroid- and retina-antigen reactive CD8+ and CD4+ T lymphocytes in the vitreous fluid of patients with birdshot chorioretinopathy

Birdshot chorioretinopathy (BSCR), a progressive form of non-infectious uveitis, is the strongest HLA-associated disease described to date, with >95% of the patients displaying HLA-A29. Since indirect evidence indicates the involvement of T cells in the etiopathology of the disease, we now isolated, cultured and analyzed the vitreous fluid-infiltrating T cells from two BSCR patients with respect to their phenotype, cytokine profile, clonal distribution and antigen specificity. Phenotypic analyses revealed the predominant presence of both CD4(+) and CD8(+) T cells in vitreous fluid. Further analyses on short term expanded and cloned T cells suggested that eye-infiltrating T cells generally displayed a Th1 like cytokine profile with secretion of high levels of IFN-γ and TNF-α. In one patient an oligoclonal CD4(+) and CD8(+) T cell infiltration, with a moderate to strongly skewed TCR Vβ usage was suggestive for an antigen driven infiltration/expansion. Indeed, a number of intraocular CD4(+) and CD8(+) T cells responded to crude retinal and choroidal lysates. These results, which demonstrate for the first time the existence of eye-antigen-specific T cells in the vitreous fluid of BSCR patients, substantiate the current view on the role of eye-antigen specific T cells in the etiopathology of BSCR.

Impact of ocular graft‐versus‐host disease on visual quality of life in patients after allogeneic stem cell transplantation: questionnaire study

Purpose:  To determine the influence of ocular complications on quality of life (QoL) 3 years after allogeneic stem cell transplantation (allo‐SCT).

Vision-related quality of life in patients with birdshot chorioretinopathy

(three Caucasians, one Chinese; three women, one man), ranging in age from 37 to 60 years, with progressive visual loss (preoperative visual acuities were 0.5, 0.25, LP+ and 1.2) and ⁄or extensive and progressive visual field defects (in all) underwent a lateral or anterior orbitotomy because of an apically located OCH. All tumours were partially removed after opening of the capsula in a piecemeal fashion. Three of them developed a retrobulbar bleeding during extubation, for which the orbits were reopened. The operation in the 4th patient, a 44-year-old woman, was complicated by profuse bleeding necessitating repeated bipolar coagulation. Final visual acuity was finger counting in 3 and no light perception in one. The incidence, clinical presentation and characteristics of orbital OCHs are nowadays well known (McNab & Wright 1989). Discussion remains on the origin of OCHs and how to deal with apically located representatives. Most OCHs present in the lateral part of the middle third of the orbit, which area is rich of vascular structures. In this region, OCHs can grow by easily pushing aside other structures (Harris 2010). These are easily accessible by an anterior or lateral orbitotomy and can be removed with subtle traction using, for instance, a cryocoagulation probe. It is this kind of OCH that has an apple shape on scans. In contrast, OCHs in the orbital apex, having a pear-shaped configuration, show a different growth pattern, in which the surrounding capsula fuses with adjacent vessels and nerves in an early stage of the disease. Total removal by orbitotomy is impeded by poor visualization, lack of manoeuvring space, excessive bleeding by traction and disruption of blood vessels, damaging of nerve vessels and the ciliary ganglion. Partial removal with or without bipolar cautery shrinkage has been suggested as an alternative procedure (McNab & Wright 1989; Harris 2010). Our experience does not support this option. Although histologic proof and size reduction was the goal of surgery in apical OCHs and these tumours were approached with minimal traction, significant bleeding during or shortly after the operation necessitated reopening of the wounds. Anaesthetic data showed no sudden increase in systemic blood pressure during or immediately after surgery. Unlike in more anteriorly located OCHs, in which the complete lesion can be removed within their capsula, the disruption of the lesion’s capsula in our four patients may be the explanation of the bleeding during or after surgery. Apparently, at least in our hands, a piecemeal OCH excision is not a viable option. Irradiation (Khan et al. 2009; Rootman et al. 2012) or a combined neurosurgical ⁄ endoscopic (Locatelli et al. 2011.) orbital approach (using neuronavigation) with microdissection and the use of an operation microscope may be better options to treat these lesions. Larger series, however, are needed to confirm this assumption.

Correlation between measurement of IL-10 and IL-6 in paired aqueous humour and vitreous fluid in primary vitreoretinal lymphoma.

Editor, P rimary vitreoretinal lymphoma (PVRL) is a rare and aggressive malignancy almost always of large diffuse B-cell origin that predominantly arises in the retina and adjacent structures (Chan et al. 2011). PVRL often masquerades as uveitis and is easily misdiagnosed. As PVRL is potentially lethal, early and accurate diagnosis is crucial for adequate treatment and prognosis. The gold standard for diagnosing PVRL requires detection of malignant lymphoid cells in vitreous or retinochoroidal biopsies that can be supported by flowcytometric evidence of monoclonality of lymphocytes in vitreous fluid (VF) (Gonzales & Chan 2007). However, outcome of cytology is frequently false negative due to fragility of cells in obtained specimens. An enzyme-linked immunosorbent assay (ELISA) measured vitreal IL-10 to IL-6 ratio greater than 1.0 is currently considered to be typical for PVRL over non-infectious uveitis (Wolf et al. 2003). Here, we present a less invasive alternative using modern multicytokine analysis on aqueous humour (AqH) instead of VF. Paracentesis to obtain AqH of the anterior chamber is safe and less invasive compared to collection of VF. However, the AqH samples consist of smaller volumes compared to undiluted VF and potentially limit the evaluation of both IL-10 and IL-6 levels by ELISA. The emerging use of multiplex bead-based array platform (Luminex), however, allows the detection and evaluation of multiple cytokines in small sample volume (<25 ll) (de Jager et al. 2003). Exploiting this exciting technique, we measured IL-10 and IL-6 levels in paired AqH and VF samples of patients (n = 11) with proven PVRL between 2005 and 2014, to investigate whether the use of AqH could replace VF. The samples were collected during diagnostic vitrectomy to confirm the diagnosis PVRL, and the remainders of the samples were used to measure IL10 to IL-6 ratios with approval from the medical–ethical institutional review board. The diagnosis of PVRL was based upon cytology/immunocytology of vitreous cells, histopathology of retinal biopsy or proven CNS lymphoma. None of the patients was treated for PVRL with intra-ocular methotrexate, rituximab, systemic chemotherapy or irradiation of the eye during/before the diagnostic vitrectomy. The samples were preserved at minus 80°C degrees immediately after harvesting. IL-10 and IL-6 levels were measured in 25 ll of undiluted sample. Correlation of the biomarkers with AqH and VF was analysed by computing the nonparametric Spearman’s rank correlation coefficient. The female/male ratio was 4/7 and the mean age of developing of lymphoma was 68.8 years (range 63– 82 years). All patients suffered from PVRL and two patients had additional CNS involvement. The geometric mean of the levels of IL-10 in AqH was 863.6 (95% CI: 169.3–4405) and in VF was 2188 (95% CI: 607.6–7880). The mean of the levels of IL-6 in AqH was 81.9 (95% CI: 45.7–147.1) and in VF was 79.1 (95% CI: 40.7–153.6). The levels of IL-10 (r = 0.92; p = 0.0002) and the levels of IL-6 (r = 0.83, p = 0.003) in paired AqH and VF strongly correlated. Accordingly, the IL-10 to IL-6 ratio in the paired AqH and VF correlated (r = 0.73, p = 0.01) (Fig. 1). The individual levels and the ratio of IL-10 and IL-6, in paired AqH and VF of PVRL patients, strongly correlate and demonstrate that the relative proportion of IL-10 to IL-6 is similar for both AqH and VF. We emphasize that the general opinion is that definite diagnosis must be made by cytologic or histopathologic evaluation of vitreous or retinochoroidal specimens that can be supported by IL-10 to IL-6 ratio. The present results suggest that the AqH IL-10 to IL-6 ratio may be as useful as the previously suggested vitreal IL-10 to IL-6 ratio and, thus, provides a less invasive alternative for the evaluation of these cytokines to support histopathology and immunocytologic evidence, or follow-up after treatment, for PVRL.

Ocular fluid analysis in children reveals interleukin‐29/interferon‐λ1 as a biomarker for juvenile idiopathic arthritis associated uveitis

Childhood uveitis is a vision‐threatening inflammatory eye disease commonly attributed to juvenile idiopathic arthritis (JIA). The pathogenesis is poorly understood, which makes clinical management challenging. We analyzed soluble mediators in ocular fluid (aqueous humor [AqH]) and serum from children with JIA‐associated uveitis and common childhood uveitis to identify potential biomarkers and investigate the ocular microenvironment of this sight‐threatening eye disease.

Electrolyte composition of retro-oil fluid and silicone oil-related visual loss

Up to one‐third of patients with intra‐ocular silicone oil (SO) tamponade for complex macula‐on retinal detachment may experience an unexplained visual loss during or after SO tamponade. Although the underlying mechanism is unknown, previous studies suggested that accumulation of retinal potassium could be involved. Hence, this study tested the hypothesis that intra‐ocular potassium levels are elevated during SO tamponade.