An update on the genetics of HLA B27-associated acute anterior uveitis

Low uveitis rates in patients with axial spondyloarthritis treated with bimekizumab: pooled results from phase 2b/3 trials

OBJECTIVES

Acute anterior uveitis ('uveitis') is a common axial spondyloarthritis (axSpA) extramusculoskeletal manifestation. Interleukin (IL)-17 is implicated in its pathogenesis, however, there is conflicting evidence for IL-17A inhibition in uveitis management. We report pooled analyses of uveitis incidence in patients receiving bimekizumab (BKZ), a monoclonal IgG1 antibody that selectively inhibits IL-17F in addition to IL-17A, from phase 2b/3 trials.

METHODS

Data were pooled for patients receiving BKZ 160 mg or placebo in the double-blind treatment period of the phase 3 BE MOBILE 1 (NCT03928704; non-radiographic axSpA) and BE MOBILE 2 (NCT03928743; radiographic axSpA) trials. Data were separately pooled for patients treated with at least one BKZ dose in the BE MOBILE trials and their ongoing open-label extension (OLE; NCT04436640), and the phase 2b BE AGILE trial (NCT02963506; radiographic axSpA) and its ongoing OLE (NCT03355573). Uveitis rates and exposure-adjusted incidence rates (EAIR)/100 patient-years (PYs) are reported.

RESULTS

In the BE MOBILE 1 and 2 double-blind treatment period, 0.6% (2/349) of patients receiving BKZ experienced uveitis vs 4.6% (11/237) receiving placebo (nominal p=0.001; EAIR (95% CI): 1.8/100 PYs (0.2 to 6.7) vs 15.4/100 PYs (95% CI 7.7 to 27.5)). In patients with history of uveitis, EAIR was lower in patients receiving BKZ (6.2/100 PYs (95% CI 0.2 to 34.8); 1.9%) vs placebo (70.4/100 PYs (95% CI 32.2 to 133.7); 20.0%; nominal p=0.004). In the phase 2b/3 pool (N=848; BKZ exposure: 2034.4 PYs), EAIR remained low (1.2/100 PYs (95% CI 0.8 to 1.8)).

CONCLUSIONS

Bimekizumab, a dual-IL-17A/F inhibitor, may confer protective effects for uveitis in patients with axSpA.

Mucosal signatures of pathogenic T cells in HLA-B*27+ anterior uveitis and axial spondyloarthritis

HLA-B*27 was one of the first HLA alleles associated with an autoimmune disease, i.e., axial spondyloarthritis (axSpA) and acute anterior uveitis (B27AAU), which cause joint and eye inflammation, respectively. Gastrointestinal inflammation has been suggested as a trigger of axSpA. We recently identified a bacterial peptide (YeiH) that can be presented by HLA-B*27 to expanded public T cell receptors in the joint in axSpA and the eye in B27AAU. While YeiH is present in enteric microbiota and pathogens, additional evidence that pathogenic T cells in HLA-B*27-associated autoimmunity may have had a prior antigenic encounter within the gastrointestinal tract remains lacking. Here, we analyzed ocular, synovial, and blood T cells in B27AAU and axSpA, showing that YeiH-specific CD8+ T cells express a mucosal gene set and surface proteins consistent with intestinal differentiation, including CD161, integrin α4β7, and CCR6. In addition, we found an expansion of YeiH-specific CD8+ T cells in axSpA and B27AAU blood compared with that from individuals acting as healthy controls, whereas influenza-specific CD8+ T cells were equivalent across groups. Finally, we demonstrated the dispensability of TRBV9 for antigen recognition. Collectively, our data suggest that, in HLA-B27-associated autoimmunity, early antigen exposure and differentiation of pathogenic CD8+ T cells may occur in enteric organs.

Persistent Inflammation Associated With HLA-B27 After Pars Plana Vitrectomy With Scleral Buckle Placement

Purpose: To report 2 cases of persistent inflammation associated with human leukocyte antigen-B27 (HLA-B27) after pars plana vitrectomy (PPV) with scleral buckling. Methods: Two cases were analyzed. Results: A 47-year-old man had pars plana vitrectomy (PPV), scleral buckle (SB) placement, and endolaser for a macula-on rhegmatogenous retinal detachment (RRD). A 61-year-old man also had uneventful PPV, SB placement, and endolaser for a macula-off RRD. Postoperatively, both patients reported eye pain and had persistent intraocular inflammation. Both were found to be HLA-B27 positive despite having no previous signs or symptoms that would warrant HLA-B27 testing. Conclusions: Discovering the source of prolonged postoperative inflammation is critical in initiating the correct treatment and removing suspicion of infection. Although intraocular inflammation associated with HLA-B27 does not often present initially after surgery, HLA-B27 testing should be considered in cases of persistent, unexpected postoperative inflammation.

Extra-musculoskeletal manifestations driving the therapeutic decision-making in patients with Spondyloarthritis: a 12-month follow-up prospective cohort study

BACKGROUND

The extra-musculoskeletal manifestations (EMMs) such as recurrent acute anterior uveitis (rAAU), psoriasis (Ps), and inflammatory bowel disease (IBD), are related to the Spondyloarthritis (SpA), as well as they are associated with disease activity and poor prognosis. However, there are no data addressing its relevance regarding therapeutic decision-making in clinical practice.

OBJECTIVE

To evaluate the impact of EMMs to drive the treatment decision-making in patients with SpA in a 12-month follow-up.

PATIENTS AND METHODS

SpA patients, according to the axial and peripheral ASAS classification criteria, as well as CASPAR criteria, with any active EMM, defined as main entry criteria, were included in this longitudinal cohort study. Individuals with a history of any disease or condition that could be associated with some of the studied endpoints, including neoplasms and infectious diseases, were excluded. Specific tools related to each EMM, including Psoriasis Area Severity Index (PASI), ophthalmologic evaluation, according to the Standardization of Uveitis Nomenclature (SUN) criteria, and gut complaints were used at baseline and during the 3-, 6- and 12-month of follow-up as outcomes measures over time. Descriptive and inferential analyses were used appropriately, including Pearson's correlation test, chi-squared test, and ANOVA. P value less than 0.05 was considered as significant.

RESULTS

A total of 560 patients were enrolled, of whom 472 meet the eligibility criteria. The majority (N = 274; 59.6%) had one or more EMM related to SpA umbrella concept. Among the EMM, the one that most influenced therapeutic decision-making was psoriasis (28.5%), followed by uveitis (17.5%) and IBD (5.5%), regardless of musculoskeletal manifestations. Clinical improvement of EMMs outcomes was observed in most patients over 12-month follow-up, especially in those with rAAU and IBD (P < 0.001).

CONCLUSION

Our results showed that EMMs guided the therapeutic decision-making in half of SpA patients, regardless of musculoskeletal condition, suggesting the inter-disciplinarity among the rheumatologist, ophthalmologist, dermatologist, and gastroenterologist plays a crucial role to manage them.

Factors Associated With Adverse Outcomes in Uveitis Related to Spondyloarthritis: Development of an Outcome Score (SpA-U)

BACKGROUND

Evaluating the efficacy and refractoriness to treatment and determining factors associated with adverse outcomes in uveitis associated with spondylarthritis (SpA) are complicated by the lack of validated outcome measures.

OBJECTIVES

The aims of this study were to develop an outcome score SpA-U in patients with uveitis associated with SpA and to determine factors associated with adverse outcomes in patients with uveitis under systemic treatment.

METHODS

The outcome score SpA-U was defined by best-corrected visual acuity, anterior chamber inflammation, macular edema and inflammation of posterior chamber, global assessment, and refractoriness to treatment. Factors associated with adverse outcomes in uveitis were studied using linear regression. For categorical factors, marginal averages and their SEs are displayed together with linear regression coefficients with 95% confidence intervals. For continuous factors, averages and SDs are reported in addition to linear regression coefficients with 95% confidence interval. Two regression coefficients are reported for each variable: unadjusted and adjusted for age at diagnosis and sex.

RESULTS

One hundred ninety-seven uveitis outbreaks were included. Sixty-two uveitis outbreaks (31%) were classified as severe, 42 as moderate (21%), and 93 as mild (47%) based on the definition and construction of outcome score. The results of the linear regression model revealed that the uveitis activity was more severe in patients with smoking history ( β = 0.34), axial and peripheral involvement ( β = 0.43), Ankylosing Spondylitis Disease Activity Score >2.1 ( β = 0.45), positive HLA-B27 ( β = 0.29), female sex ( β = 0.19), patients with C-reactive protein elevation ( β = 0.002), and bilateral ocular involvement ( β = 0.32). At the same time, shorter disease evolution ( β = -0.02) was associated with less severe uveitis activity.

CONCLUSION

We have determined factors associated with adverse outcomes in patients with uveitis associated with SpA by developing an outcome score SpA-U that integrates ocular inflammatory activity, visual acuity, global assessment, and refractoriness to treatment.

Biomolecular Mechanisms of Autoimmune Diseases and Their Relationship with the Resident Microbiota: Friend or Foe?

The use of innovative approaches to elucidate the pathophysiological mechanisms of autoimmune diseases, as well as to further study of the factors which can have either a positive or negative effect on the course of the disease, is essential. In this line, the development of new molecular techniques and the creation of the Human Genome Program have allowed access to many more solutions to the difficulties that exist in the identification and characterization of the microbiome, as well as changes due to various factors. Such innovative technologies can rekindle older hypotheses, such as molecular mimicry, allowing us to move from hypothesis to theory and from correlation to causality, particularly regarding autoimmune diseases and dysbiosis of the microbiota. For example, Prevotella copri appears to have a strong association with rheumatoid arthritis; it is expected that this will be confirmed by several scientists, which, in turn, will make it possible to identify other mechanisms that may contribute to the pathophysiology of the disease. This article seeks to identify new clues regarding similar correlations between autoimmune activity and the human microbiota, particularly in relation to qualitative and quantitative microbial variations therein.

The Risk of Major Adverse Cardiovascular Events in Ankylosing Spondylitis Patients With a History of Acute Anterior Uveitis: A Nationwide, Population Based Cohort Study

Background

To investigate the association between a history of acute anterior uveitis (AAU) and the risk of major adverse cardiovascular events (MACE) among patients with ankylosing spondylitis (AS).

Methods

We identified 38,691 newly diagnosed AS patients between 2003 and 2013 from the Taiwan National Health Insurance Research Database. The exposure group was defined as people with uveitis diagnosis by ophthalmologist before AS diagnosis date. The incidence of MACE in patients with AS according to the International Classification of Diseases, Ninth Revision. We randomly selected a comparison group without a history of AAU at a 1:4 ratio matched by age, sex, and index year in relation to the risk of developing MACE. We used cox proportional hazard regression model to compare the risk of MACE between groups, shown as adjusted hazard ratios (aHRs) with 95% confidence intervals (CI). Further subgroup analysis and sensitivity tests were also performed.

Results

There were 3,544 patients in the AAU group and 14,176 patients in the non-AAU group. The aHR of MACE for the AAU group was 0.79 (95% CI = 0.57–1.10) at a 1:4 ratio for age, sex and index year. Sensitivity analyses using various adjustment variables showed consistent results. Cox proportional hazard regression model demonstrated that use of non-steroidal anti-inflammatory drugs (NSAIDs) was associated with an increased risk of MACE in this cohort (HR = 3.44; 95% CI = 2.25–5.25).

Conclusion

This cohort study showed that subjects with AAU was not associated with the risk of MACE among AS patients, compared to non-AAU controls.

Risk of a subsequent diagnosis of inflammatory bowel disease in subjects with ophthalmic disorders associated with inflammatory bowel disease: a retrospective cohort analysis of UK primary care data

OBJECTIVES

Ophthalmic conditions including anterior uveitis (AU), episcleritis and scleritis may occur in association with the inflammatory bowel diseases (IBD) as ophthalmic extraintestinal manifestations. The aim of this study was to assess the risk of a later IBD diagnosis in those presenting with IBD associated ocular inflammation (IAOI).

DESIGN

Retrospective cohort study.

SETTING

Primary care UK database.

PARTICIPANTS

38 805 subjects with an IAOI were identified (median age 51 (38-65), 57% women) and matched to 153 018 subjects without IAOI.

MEASURES

The risk of a subsequent diagnosis of IBD in subjects with IAOIs compared with age/sex matched subjects without IAOI. HRs were adjusted for age, sex, body mass index, deprivation, comorbidity, smoking, baseline axial arthropathy, diarrhoea, loperamide prescription, anaemia, lower gastrointestinal bleeding and abdominal pain.Logistic regression was used to produce a prediction model for a diagnosis of IBD within 3 years of an AU diagnosis.

RESULTS

213 (0.6%) subsequent IBD diagnoses (102 ulcerative colitis (UC) and 111 Crohn's disease (CD)) were recorded in those with IAOIs and 329 (0.2%) (215 UC and 114 CD) in those without. Median time to IBD diagnosis was 882 (IQR 365-2043) days in those with IAOI and 1403 (IQR 623-2516) in those without. The adjusted HR for a subsequent diagnosis of IBD was 2.25 (95% CI 1.89 to 2.68), p<0.001; for UC 1.65 (95% CI 1.30 to 2.09), p<0.001; and for CD 3.37 (95% CI 2.59 to 4.40), p<0.001 in subjects with IAOI compared with those without.Within 3 years of an AU diagnosis, 84 (0.5%) subjects had a recorded diagnosis of IBD. The prediction model performed well with a C-statistic of 0.75 (95% CI 0.69 to 0.80).

CONCLUSIONS

Subjects with IAOI have a twofold increased risk of a subsequent IBD diagnosis. Healthcare professionals should be alert for potential signs and symptoms of IBD in those presenting with ophthalmic conditions associated with IBD.

Down Syndrome-Associated Arthritis (DA): Diagnostic and Management Challenges

Down syndrome (DS) is one of the most common birth defects in the United States, the most common genomic disorder of intellectual disability, and results from trisomy 21. This chromosome disorder causes an extensive, heterogenous phenotype that results in a broad presentation of symptoms that includes atlantoaxial instability, congenital heart defects, muscle hypotonia, hypothyroidism, hematologic disorders, recurrent infections, and autoimmune diseases. The autoimmune diseases are caused by immune system dysregulation that results in increased pro-inflammatory cytokines, along with other innate and adaptive immune system dysregulation. This is the likely cause of the increased risk of inflammatory arthritis or Down syndrome-associated arthritis (DA) seen in individuals with DS. Most individuals with DA present with polyarticular (five or more joints with arthritis at presentation of disease), rheumatoid factor and anti-nuclear antibody negative disease that is aggressive with bone and joint damage at presentation. There is notable delay in diagnosis of DA as there are no formal guidelines on screening or monitoring for inflammatory arthritis in individuals with DS. Once diagnosed, and despite aggressive therapy with disease modifying antirheumatic drugs, disease burden is high for those with DA. Therapy can also be challenging for those with DA as many require second and third-line disease modifying therapies. Many also struggle with medication toxicity and ineffectiveness that further causes challenges with management and outcomes. The purpose of this current review is to provide an up-to-date summary of the literature related to DA in children and adolescents with focus on presentation, diagnosis, and management considerations, along with current barriers that inhibit optimal care.

Uveitis as a Risk Factor for Developing Acute Myocardial Infarction in Ankylosing Spondylitis: A National Population-Based Longitudinal Cohort Study

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease. Excess cardiovascular risks were well recognized in patients with AS and were attributed to prolonged systemic inflammation. Uveitis is one of the most common extra-articular symptoms of AS and is also considered an indicator of systemic inflammation. This study aimed to investigate whether uveitis was a risk factor for developing acute myocardial infarction (AMI) in patients with AS using the National Health Insurance Research Database (NHIRD).

Methods

Data were collected from the NHIRD over a fifteen-year period. Variables were analyzed using the Pearson chi-square test and Fisher’s exact test. Risk factors for the occurrence of AMI were examined by calculating hazard ratio. Kaplan-Meier analysis was performed to compare the cumulative incidence of AMI in the uveitis and non-uveitis cohorts.

Results

A total of 5905 patients with AS were enrolled, including 1181 patients with uveitis (20%) and 4724 patients without uveitis (80%). The Kaplan–Meier method with the log-rank test showed that the uveitis group had a significantly higher cumulative hazard for patients with AMI than the non-uveitis group (p < 0.001). The adjusted hazard ratio (aHR) of AMI was higher in the uveitis group than in the non-uveitis group (aHR = 1.653, p < 0.001). Stratified analysis revealed that patients with uveitis had an increased risk of developing AMI regardless of their sex (male/female aHR = 1.688/1.608, p < 0.001). Patients with uveitis in all age groups were independently associated with an increased risk of developing AMI compared to those without uveitis (20–39 years/40–59 years/≥ 60 years, aHR = 1.550, 1.579, 3.240, p < 0.001). Patients with uveitis had a higher probability of developing AMI regardless of comorbidities. Uveitis patients with comorbidities had a higher risk of developing AMI compared to uveitis patients without comorbidities.

Conclusion

Uveitis is a significant risk factor for developing AMI in patients with AS. Physicians should be aware of the potential cardiovascular risk in AS patients with uveitis, especially simultaneously with other traditional risk factors of AMI. Further prospective studies are needed to elucidate the underlying mechanism between uveitis and AMI in patients with AS.

Unilateral acute anterior uveitis with macular edema following the use of sildenafil citrate in a patient with HLA-B27 positivity

Purpose

To present a case of acute anterior uveitis with macular edema associated with sildenafil citrate use in an HLA-B27 positive patient.

Observations

A 54-year-old Caucasian male presented at an ophthalmology tertiary center with complaint of pinkish discoloration, irritation, and photophobia in the left eye (OS). He noted that these symptoms appeared one day after using sildenafil for the first time to treat his erectile dysfunction. The patient had no significant ocular history besides refractive surgery in both eyes (OU) and his medical history was insignificant. Best-corrected visual acuity (BCVA) was 20/20 in the right eye (OD) and 20/25 in OS. Slit-lamp-examination (SLE) demonstrated trace cells and 1+ flare in the anterior chamber (AC) in OS and was nonrevealing in AC in OD. Spectral domain optical coherence tomography (SD-OCT) showed parafoveal subretinal hyperreflective deposits in OU. The patient was diagnosed with acute anterior uveitis (AAU) in the left eye and was placed on topical prednisolone acetate.At 2-week follow-up, the patient reported that his eye symptoms had improved since starting topical steroids but worsened again two days after he had used sildenafil for a second time. In OS, best-corrected visual acuity (BCVA) worsened to 20/40, and SLE revealed 1+ cells and 1+ flare in AC. SD-OCT revealed cystoid macular edema only in OS. Fluorescein angiography showed mild staining around the optic disc and significant macular leakage in OS and minimal macular leakage in OD. Uveitis evaluations revealed that the patient was human leukocyte antigen-27 (HLA-B27) positive. The patient was asked to remain off sildenafil and continue topical prednisolone acetate. At 3-month follow-up, BCVA improved to 20/20 in OS with no evidence of active inflammation.

Conclusions and importance

Sildenafil citrate use might be associated with new onset of intraocular inflammation in predisposed patients. Further studies are necessary to establish this relationship.

Managing Psoriatic Arthritis With Inflammatory Bowel Disease and/or Uveitis

Psoriatic arthritis (PsA) is a chronic inflammatory disease that presents with psoriasis (PsO), peripheral and axial arthropathy. The heterogeneity of disease presentation leads to the term "psoriatic disease (PsD)" which is thought to better encompass the range of clinical manifestations. PsA is associated with several comorbidities such as cardiovascular diseases, metabolic syndrome and other extra-articular manifestations including uveitis, and inflammatory bowel disease (IBD). While novel therapeutics are being developed following advances in our understanding of the pathogenesis of the disease, the diverse combinations of PsA with its various comorbidities still pose a clinical challenge in managing patients with PsA. This article reviews our current understanding of the pathogenesis of PsA and how various pathways in the pathogenesis lead to the two comorbid extra-articular manifestations - uveitis and IBD. We also review current evidence of treatment strategies in managing patients with PsA with comorbidities of uveitis and/or IBD.

Uveitis-related Factors in Patients With Spondyloarthritis: TReasure Real-Life Results

PURPOSE

Spondyloarthritis (SpA) is a group of diseases with overlapping skeletal and extra-articular features. Acute anterior uveitis (AAU) is the most common extra-articular manifestation of SpA. The relation between AAU and SpA is well defined in the current literature. Our study aims to analyze the frequency and factors associated with AAU in different forms of SpA in a large nationwide cohort of Turkish SpA patients.

DESIGN

Retrospective cohort study.

METHODS

The data were obtained from the TReasure database, which compiles data from records of the web-based Rheumatoid Arthritis (RA) and SpA patients treated with biological disease-modifying anti-rheumatismal drugs from different regions of Turkey. The clinical characteristics of SpA and uveitis are recorded.

RESULTS

Data of the 4,297 SpA patients were included in the study. Overall, 475 of 4,297 patients (11.0%) had experienced 1 or more episodes of uveitis. SpA patients with older age (P < .001), a smoking history (P = .004), delayed diagnosis (P = .001), longer disease duration (P < .001), arthritis (P < .001), positive HLA-B27 (P < .001), a family history of SpA (P < .001), and radiographic damage (presence of sacroiliitis, syndesmophytes, bamboo spine, hip involvement) (P < .001 for all) more commonly had uveitis. On the other hand, uveitis was less prevalent in patients with psoriasis and psoriatic arthritis (P < .001 for both).

CONCLUSION

Uveitis may be the key feature leading to SpA diagnosis. Patients with radiographic damage and long disease duration have an increased risk for uveitis in both male and female SpA patients. Patients with uveitis should be referred to a rheumatologist for a thorough evaluation of SpA.

Immunomodulation with IL-17 and TNF-α in spondyloarthritis: focus on the eye and the central nervous system

Tumor necrosis factor alpha (TNF-α) and interleukin-17 (IL-17) are two pro-inflammatory cytokines involved in the pathophysiology of spondyloarthritis (SpA). Therapies targeting TNF-α or IL-17 are used as a second line among SpA patients failing non-steroidal anti-inflammatory drugs. The choice of such treatment has to take into account the patient’s comorbidities. Neurologic diseases are common and their association with SpA deserves to be studied. Therefore, the role of TNF-α and IL-17 cytokines is worth investigating in these neuropsychiatric diseases. This review aimed to explore the role of TNF-α and IL-17 in the pathogenesis of uveitis, multiple sclerosis, neuromyelitis optica, Alzheimer’s disease, Parkinson’s disease and depression. This update is critical to guide the therapeutic management of these co-morbidities in SpA patients.

The role of the inflammasomes in the pathogenesis of uveitis

Uveitis is a diverse group of sight-threatening intraocular inflammatory diseases usually causing eye redness, pain, blurred vision, and sometimes blindness. Although the exact pathogenesis of uveitis is not yet clear, accumulating evidences have shown that an imbalanced regulation of immune responses caused by a combination of genetic and environmental factors are implicated in the pathogenesis of this disease. As critical regulators of inflammation, inflammasomes have been assumed to play a role in the pathogenesis of uveitis. Recent studies have reported the association between a number of genetic variants in inflammasome related genes (such as NLRP3, NLRP1, NLRC4 and AIM2) with increased risk to uveitis. Mounting evidence have shown an aberrant activation of the NLRP3 inflammasome in both uveitis patients and murine models of uveitis. Some studies explored the intervention of uveitis via modulating inflammasome activity in the eye. This review aims at summarizing the main findings of these studies, proposing the possible mechanism whereby inflammasomes affect the susceptibility to develop uveitis, and giving a perspective for future studies, which may further improve our understanding about the role of inflammasomes and related cytokines in the pathogenesis of uveitis, and may hopefully lead to new therapeutics by targeting inflammasomes.

Epidemiology of pediatric uveitis and associated systemic diseases

BACKGROUND

The early detection of uveitis associated with systemic inflammatory disease in children is important for proper treatment and prognosis. However, the diagnosis may be delayed because of difficulties in childhood examinations and early minor systemic symptoms. The objective of our study was to identify the pattern of childhood uveitis and investigate the frequency and clinical features of rheumatic diseases in pediatric patients with uveitis.

METHODS

This retrospective observational study reviewed the medical records of children (age ≤ 18 years) with uveitis at a Korean tertiary hospital between January 2005 and December 2018. Data collected included the age at onset of uveitis, sex, anatomic location of ocular inflammation, comorbid disease (including systemic inflammatory disease), ocular complications, relevant laboratory data, and treatment. Fisher's exact test was used to compare categorical variables and the Mann-Whitney U test was used to compare continuous variables. A p-value of < 0.05 was considered statistically significant.

RESULTS

A total of 155 pediatric patients with uveitis were included in this study. The median age at diagnosis was 13.0 years (interquartile range, 9.5-16.0 years). The male-to-female ratio was 1.09. The process was unilateral in 51.6% of children. Anterior uveitis, panuveitis, intermediate uveitis, and posterior uveitis represented 51.6, 26.5, 6.5, and 1.9% of the cases, respectively. Idiopathic uveitis (65.2%) was the most frequent type of uveitis. Systemic rheumatic disease associations were responsible for 28.4% of the cases, among which juvenile idiopathic arthritis (JIA) was the most frequent cause (14.8%). Human leukocyte antigen (HLA)-B27 and antinuclear antibody (ANA) positive rates were significantly higher in patients with JIA than in those with idiopathic uveitis (p = 0.006 and p = 0.007, respectively).

CONCLUSIONS

Approximately one-third of children with uveitis in Korea have a systemic rheumatic disease, of which JIA accounts for the majority of cases. HLA-B27 and ANA can serve as risk factors for JIA-associated uveitis.

Recent Developments in HLA B27 Anterior Uveitis

There has been steady progress in understanding the pathogenesis, clinical features, and effective treatment of acute anterior uveitis (AU) over the past 5 years. Large gene wide association studies have confirmed that AU is a polygenic disease, with overlaps with the seronegative arthropathies and inflammatory bowel diseases, associations that have been repeatedly confirmed in clinical studies. The role of the microbiome in AU has received increased research attention, with recent evidence indicating that human leukocyte antigen B27 (HLA B27) may influence the composition of the gut microbiome in experimental animals. Extensive clinical investigations have confirmed the typical features of acute AU (AAU) and its response to topical, regional and systemic immunosuppressive treatment. Increased understanding of the role of cytokines has resulted in studies confirming the value of anti-cytokine therapy [anti-tumor necrosis factor (anti-TNF) and interleukin 6 (IL-6) therapy] in severe and recurrent cases of AAU, particularly in subjects with an associated spondyloarthopathy (SpA) and in juvenile idiopathic arthritis (JIA)-associated AAU.

The roles of ERAP1 and ERAP2 in autoimmunity and cancer immunity: New insights and perspective

Autoimmunity and cancer affect millions worldwide and both, in principal, result from dysregulated immune responses. There are many well-known molecules involved in immunological process playing as a double-edged sword, by which associating autoimmune diseases and cancer. In this regard, Endoplasmic reticulum aminopeptidases (ERAP) 1, which belongs to the M1 family of aminopeptidases, plays a central role as a "molecular ruler", proteolyzing of N-terminal of the antigenic peptides before their loading onto HLA-I molecules for antigen presentation in the Endoplasmic Reticulum (ER). Several genome-wide association studies (GWAS) highlighted the significance of ERAP1 and ERAP2 in autoimmune diseases, including Ankylosing spondylitis, Psoriasis, Bechet's disease, and Birdshot chorioretinopathy, as well as in cancers. The expression of ERAP1/2 is mostly altered in different cancers compared to normal cells, but how this affects anti-cancer immune responses and cancer growth has been little explored. Recent studies on the immunological outcomes and the catalytic functions of ERAP1 and ERAP2 have provided a better understanding of their potential pathogenetic role in autoimmunity and cancer. In this review, we summarize the role of ERAP1 and ERAP2 in the autoimmune diseases and cancer immunity based on the recent advances in GWAS studies.

Cardiac conduction disturbances in patients with ankylosing spondylitis: results from a 5-year follow-up cohort study

Objectives

To describe electrocardiographic (ECG) development in patients with ankylosing spondylitis (AS) and identify associations between baseline characteristics and cardiac conduction disturbances (CCD) at 5-year follow-up.

Methods

In a longitudinal cohort study, 172 patients (54% men, mean age (SD) of 50 (13) years at baseline) with AS underwent ECG, physical examination, questionnaires and laboratory testing at baseline and at 5-year follow-up. Descriptive statistics and univariate and age- and sex-adjusted logistic regression analyses were used. CCD included both atrioventricular and intraventricular blocks.

Results

Twenty-three of the 172 patients (13.4%) had a CCD at follow-up. Eight patients had developed a new CCD and eight had normalised their ECG. In the age- and sex-adjusted analyses, CCD at baseline (OR 24.8, 95% CI 7.3 to 84.5), male sex (OR 6.4, 95% CI 2.0 to 20.8), history of anterior uveitis (OR 4.4, 95% CI 1.3 to 14.5), higher ASDAS-CRP (OR 2.3, 95% CI 1.3 to 4.0), greater waist circumference (OR 1.3, 95% CI 1.1 to 1.6, per 5 cm), and medication with antiplatelets (OR 7.0, 95% CI 1.5 to 31.8) and beta-blockers (OR 3.4, 95% CI 1.0 to 11.5) were associated with a CCD at follow-up. Higher age and longer symptom duration were highly correlated and were both associated with a CCD at follow-up.

Conclusions

The presence of CCD in AS is in part dynamic and associated with both AS and non-AS characteristics. Our results suggest that patients especially prone to present with CCDs are older men with a previous CCD, longer symptom duration, higher AS disease activity, a history of anterior uveitis and medication reflecting cardiovascular disease.

The LMP2 CfoI polymorphism is associated with ankylosing spondylitis (AS) risk but not with acute anterior uveitis (AAU): A meta-analysis

BACKGROUND

Ankylosing spondylitis (AS) is one of the most common chronic inflammatory disorders affecting the sacroiliac joints, spine, and peripheral joints. Apart from HLA-B27, the LMP2 gene has been shown to play a role in the pathogenesis of AS as well as AAU in AS. However, genetic associations between LMP2 CfoI polymorphism and AS and AAU were inconclusive. We aimed to investigate the correlation of LMP2 CfoI polymorphism and AS and AAU using meta-analysis.

METHODS

An exhaustive search was conducted using the PubMed, Embase, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI) electronic databases. The strength association was assessed by crude ORs with 95% CI.

RESULTS

Eight eligible records with 449 AS patients and 317 healthy controls were included in the present study. The allelic model of the LMP2 CfoI polymorphism is associated with AS risk (OR = 0.60, 95%CI = [0.32, 1.11], P = .003). A stratified analysis based on ethnicity has shown that the allelic model of LMP2 CfoI was associated with AS in the Caucasian population (OR = 0.72, 95%CI = [0.55, 0.93], P = .01) but not in the Asian population (P > .05). Furthermore, no association was detected between LMP2 CfoI polymorphism and AS complication (AAU).

CONCLUSION

Our combined results revealed that the allelic model of LMP2 CfoI might be a protective factor for AS in the Caucasian population. Nevertheless, future studies on different ethnicities with larger sample sizes are needed to obtain a more convincing result.

Clinical Features and Treatment of Down Syndrome Arthropathy: Experience from Two US Tertiary Hospitals

BACKGROUND

Arthropathy of Down syndrome (DA) is largely under-recognized, with an average 2-year delay in diagnosis. Most patients present with polyarthritis, and treatment has historically been challenging.

OBJECTIVES

Our objective was to investigate the clinical features and treatment of DA in the largest cohort reported to date.

METHODS

In a retrospective chart review at two tertiary care hospitals, International Classification of Diseases, ninth revision, clinical modification (ICD-9-CM) codes for Down syndrome (DS) and juvenile idiopathic arthritis (JIA), between 1 January 1995 and 31 December 2015, were identified and charts reviewed.

RESULTS

In total, 43 patients were identified, with an average (± standard deviation [SD]) follow-up period of 6 ± 4.4 years. The average age of symptom onset was 7.4 ± 3.9 years, with a mean delay of 19 ± 17 months from symptom onset to diagnosis. At diagnosis, 77% of patients had morning stiffness and 72% had abnormal laboratory values; there was an average of 15 ± 13 active joints (range 1-56). Treatment approaches varied, and there was a significant decrease in joints with active arthritis (p < 0.001), with 25% and 39% having at least one change in disease-modifying antirheumatic drug (DMARD) and biologic therapy, respectively. DMARD therapy was discontinued in 60% because of side effects, and 39% had inadequate response to first-line biologic therapy.

CONCLUSIONS

DA remains under-recognized, with delays in diagnosis and extensive musculoskeletal symptoms at presentation. While DA can improve with current therapy for JIA (corticosteroids, DMARDs, biologics), barriers include medication toxicity, intolerance, and ineffectiveness. Earlier diagnosis through improved screening and more targeted treatment may allow for earlier disease control and better outcomes.

Fungal-derived cues promote ocular autoimmunity through a Dectin-2/Card9-mediated mechanism

Uveitis (intraocular inflammation) is a leading cause of loss of vision. Although its aetiology is largely speculative, it is thought to arise from complex genetic-environmental interactions that break immune tolerance to generate eye-specific autoreactive T cells. Experimental autoimmune uveitis (EAU), induced by immunization with the ocular antigen, interphotoreceptor retinoid binding protein (IRBP), in combination with mycobacteria-containing complete Freund's adjuvant (CFA), has many clinical and histopathological features of human posterior uveitis. Studies in EAU have focused on defining pathogenic CD4⁺ T cell effector responses, such as those of T helper type 17 (Th17) cells, but the innate receptor pathways precipitating development of autoreactive, eye-specific T cells remain poorly defined. In this study, we found that fungal-derived antigens possess autoimmune uveitis-promoting function akin to CFA in conventional EAU. The capacity of commensal fungi such as Candida albicans or Saccharomyces cerevisae to promote IRBP-triggered EAU was mediated by Card9. Because Card9 is an essential signalling molecule of a subgroup of C-type lectin receptors (CLRs) important in host defence, we evaluated further the proximal Card9-activating CLRs. Using single receptor-deficient mice we identified Dectin-2, but not Mincle or Dectin-1, as a predominant mediator of fungal-promoted uveitis. Conversely, Dectin-2 activation by α-mannan reproduced the uveitic phenotype of EAU sufficiently, in a process mediated by the Card9-coupled signalling axis and interleukin (IL)-17 production. Taken together, this report relates the potential of the Dectin-2/Card9-coupled pathway in ocular autoimmunity. Not only does it contribute to understanding of how innate immune receptors orchestrate T cell-mediated autoimmunity, it also reveals a previously unappreciated ability of fungal-derived signals to promote autoimmunity.

Bayesian analysis of genetic association across tree-structured routine healthcare data in the UK Biobank

Genetic discovery from the multitude of phenotypes extractable from routine healthcare data can transform our understanding of the human phenome and accelerate progress towards precision medicine. However, a critical question when analysing high-dimensional and heterogeneous data is how to best interrogate increasingly specific subphenotypes whilst retaining statistical power to detect genetic associations. Here we develop and employ a novel Bayesian analysis framework that exploits the hierarchical structure of diagnosis classifications to analyse genetic variants against UK Biobank disease phenotypes derived from self-reporting and hospital episode statistics. Our method displays a more than 20% increase in power to detect genetic effects over other approaches and identifies novel associations between classical human leukocyte antigen (HLA) alleles and common immune-mediated diseases (IMDs). By applying the approach to genetic risk scores (GRSs) we reveal the extent of genetic sharing between IMDs and expose differences in disease perception or diagnosis with potential clinical implications.

Lack of association of C3 gene with uveitis: additional insights into the genetic profile of uveitis regarding complement pathway genes

Uveitis is a devastating ocular disease that causes blindness. Our previous studies have achieved great advancements in depicting the genetic profiles of uveitis regarding complement pathway genes. This study aimed to provide additional insights into this interest by testing the "central" factor of the complement system, C3 gene variants, in two uveitis entities. Eight haplotype-tagging SNPs of C3 gene were genotyped in 141 anterior uveitis (AU), 158 non-infectious intermediate and posterior uveitis (NIPU) and 293 controls. The results showed that none of the tagging SNPs had a significant association with uveitis (P > 0.05), either in the global uveitis or subtypes. Although rs428453 showed a nominal association with NIPU subtype in the recessive model (P = 0.042), the P value could not withstand the Bonferroni correction (P _corr > 0.05). Stratification analyses according to HLA-B27 status and correlation analysis still did not find any significant interactions or genetic markers regarding AU. Logistic regression analysis also revealed no gender-related epistatic effects of C3 on uveitis. Two haplotype blocks were defined across the C3 locus but neither of them was significantly associated with uveitis or subtypes. This study shows no significant association of the C3 gene with uveitis, suggesting C3 confers either no or limited risk for uveitis susceptibility.

HLA-B27 Anterior Uveitis: Immunology and Immunopathology

Acute anterior uveitis (AAU) is the commonest type of uveitis and HLA-B27 AAU is the most frequently recognized type of acute anterior uveitis and anterior uveitis overall. Recent evidence indicates that acute anterior uveitis is a heterogenous disease, is polygenic and is frequently associated with the spondyloarthropathies (SpA). Studies of patients with AAU and animal models of disease indicate a role for innate immunity, the IL-23 cytokine pathway and exogenous factors, in the pathogenesis of both SpA and acute anterior uveitis. Recently described genetic associations cluster around immunologic pathways, including the IL-17 and IL-23 pathways, antigen processing and presentation, and lymphocyte development and activation. Patients with ankylosing spondylitis (AS) and AAU share other genetic markers, such as ERAP-1, which show strong evidence of gene-gene interaction and point to new mechanisms of disease pathogenesis. These observations have major implications for understanding the pathogenesis of HLA-B27 diseases, such as AAU, and may lead to the development of more specific therapy for AAU. Received 6 January 2016; revised 6 February 2016; accepted 18 February 2016; published online 31 May 2016.

Mincle Activation and the Syk/Card9 Signaling Axis Are Central to the Development of Autoimmune Disease of the Eye

Uveitis, which occurs in association with systemic immunological diseases, presents a considerable medical challenge because of incomplete understanding of its pathogenesis. The signals that initiate T cells to target the eye, which may be of infectious or noninfectious origin, are poorly understood. Experimental autoimmune uveoretinitis (EAU) develops in mice immunized with the endogenous retinal protein interphotoreceptor retinoid binding protein in the presence of the adjuvant CFA. EAU manifests as posterior ocular inflammation consisting of vasculitis, granulomas, retinal damage, and invasion of self-reactive T cells, which are key clinical features of human uveitis. Our studies uncover Card9 as a critical genetic determinant for EAU. Card9 was responsible for Th17 polarization and Th17-associated Ag-specific responses, but not Th1-associated responses. Nonetheless, Card9 expression was essential for accumulation of both lineages within the eye. Consistent with its recently identified role as an intracellular signaling mediator for C-type lectin receptors (CLRs), a Card9-dependent transcriptional response in the neuroretina was observed involving genes encoding the CLRs Dectin-1, Dectin-2, and Mincle. Genetic deletion of these individual CLRs revealed an essential role for Mincle. Mincle activation was sufficient to generate the EAU phenotype, and this required activation of both Syk and Card9. In contrast, Dectin-1 contributed minimally and a possible repressive role was shown for Dectin-2. These findings extend our understanding of CLRs in autoimmune uveitis. The newly identified role of Mincle and Syk/Card9-coupled signaling axis in autoimmune uveitis could provide novel targets for treatment of patients with ocular inflammatory disease.

In vivo confocal microscopy of inflammatory cells in the corneal subbasal nerve plexus in patients with different subtypes of anterior uveitis

PURPOSE

Previously we could show increased numbers and densities of dendritic-like cells (DLCs) in the subbasal nerve plexus of the central cornea in patients with herpetic anterior uveitis (HAU). Now we aimed to explore these and other inflammatory cells seen in this layer in different subtypes of anterior uveitis using in vivo confocal microscopy.

METHODS

Consecutive eyes of patients with different types of anterior uveitis, HAU, Fuchs' uveitis syndrome (FUS), juvenile idiopathic arthritis (JIA) and human leucocyte antigen (HLA)-B27-related anterior uveitis were examined in vivo with the combination of Heidelberg Retina Tomograph II/III and Rostock Cornea Module. The contralateral eye was used as control. Inflammatory cells were defined on the basis of their morphology: type 1 (DLCs) and type 2 (cell bodies lacking dendrites). Frequencies were evaluated statistically in each group.

RESULTS

The difference between means of type 1 cells density of affected eyes in all four groups was significant (one-way analysis of variance (ANOVA) p=0.039). The difference between means of type 1 cell densities of affected eyes in patients with HAU (96.8±44.2 cells/mm², n=10) and that of patients with FUS (46.4±38.7 cells/mm², n=17) was significant (Tukey's post hoc p=0.025), whereas the difference between patients with HAU and JIA (53.3±34.5 cells/mm², n=7) and patients with HAU and HLA-B27 (63.1±59.2 cells/mm², n=10) was not significant (Tukey's post hoc p=0.181 and 0.300). In contrast, the following means resulted from the evaluation of type 2 cells: the difference between means of affected eyes in all four groups was not significant (one-way ANOVA p=0.185). Density means difference of patients with HAU (44.9±22.6 cells/mm², n=5) and that of FUS (20.0±11.0 cells/mm², n=2) and that of patients with JIA (56.0±18.3 cells/mm², n=2) and that of HLA-B27 (36.1±24.1 cells/mm², n=5) was not significant (Tukey's post hoc p=0.302, 0.877 and 0.739). The contralateral eye of all patient groups showed also an inflammatory cell infiltrate of lesser extent.

CONCLUSIONS

The high density and morphology of DLCs in the central cornea of patients with HAU assessed by confocal microscopy supports the clinical diagnosis of HAU especially when compared with patients with FUS but not when compared with patients with JIA or HLA-B27.

CLINICAL RELEVANCE

This study suggests that the non-invasive confocal microscopy of the cornea is capable of supporting a clinical diagnosis in patients with uveitis.

Does evaluation of the ligamentous compartment enhance diagnostic utility of sacroiliac joint MRI in axial spondyloarthritis?

Introduction

Inflammation of the sacroiliac joints (SIJ) is a fundamental clinical feature of axial spondyloarthritis (SpA). The anatomy of the irregularly shaped SIJ is complex with an antero-inferior cartilaginous compartment containing central hyaline and peripheral fibrocartilage, and a dorso-superior ligamentous compartment. Several scoring modules to systematically assess SIJ magnetic resonance imaging (MRI) in SpA have been developed. Nearly all of them are based on the cartilaginous joint compartment alone. However, there are only limited data about the frequency of inflammatory lesions in the ligamentous compartment and their potential diagnostic utility in axial SpA. We therefore aimed to evaluate the ligamentous compartment on sacroiliac joint MRI for lesion distribution and potential incremental value towards diagnosis of SpA over and above the traditional assessment of the cartilaginous compartment alone.

Methods

Two independent cohorts of 69 and 88 consecutive back pain patients ≤50 years were referred for suspected SpA (cohort A) or acute anterior uveitis plus back pain (cohort B). Patients were classified according to rheumatologist expert opinion based on clinical, radiographic and laboratory examination as having nonradiographic axial SpA (nr-axSpA; n = 51), ankylosing spondylitis (n = 34), or nonspecific back pain (NSBP; n = 72). Five blinded readers assessed SIJ MRI globally for presence/absence of SpA. Bone marrow edema (BME) and fat metaplasia were recorded in the cartilaginous and ligamentous compartment. The incremental value of evaluating the ligamentous additionally to the cartilaginous compartment alone for diagnosis of SpA was graded qualitatively. We determined the lesion distribution between the two compartments, and the impact of the ligamentous compartment evaluation on diagnostic utility.

Results

MRI bone marrow lesions solely in the ligamentous compartment in the absence of lesions in the cartilaginous compartment were reported in just 0–2.0/0–4.0 % (BME/fat metaplasia) of all subjects. Additional assessment of the ligamentous compartment was regarded as essential for diagnosis in 0 and 0.6 %, and as contributory in 28.0 and 7.7 % of nr-axSpA patients in cohorts A and B, respectively. Concomitant BME in both compartments was evident in 11.6–42.0 % of nr-axSpA and 2.1–2.4 % of NSBP patients.

Conclusion

Assessing the ligamentous compartment on SIJ MRI provided no incremental value for diagnosis of axial SpA. However, concomitant BME in both compartments may help discriminate nr-axSpA from NSBP.

Investigation of the relationship between the onset of arthritis and uveitis in genetically predisposed SKG mice

Introduction

Systemic rheumatic conditions are often accompanied by intraocular inflammatory disease (termed uveitis). Despite the frequent manifestation of uveitis with arthritis, very little is understood of the underlying mechanisms that mediate the eye’s susceptibility to disease. The genetically susceptible SKG mouse strain develops arthritis that arises from an inherent mutation that disrupts T-cell antigen receptor signal transduction and thymic selection. The ensuing T-cell–mediated disease is further modulated through exposure to microbial triggers. The purpose of this study was to elucidate how a genetically determined shift in the T-cell repertoire toward self-reactive T cells that drive arthritis influences uveitis in SKG mice.

Methods

SKG mice (BALB/c mice that harbor the W163C point mutation in zeta-chain-associated protein kinase 70 [i.e., ZAP-70]) were housed under arthritis-resistant, specific pathogen–free conditions. Arthritis was induced by intraperitoneal injection with fungal glucans (zymosan or curdlan). Arthritis onset and severity were evaluated by clinical scoring, histopathology and infrared imaging within the joints. Periocular traits involving blepharoconjunctivitis were evaluated by clinical scoring and histology. Eyes were evaluated for signs of anterior uveitis using intravital videomicroscopy to document cell-trafficking responses within the iris vasculature and stroma and by histology to detect inflammatory infiltrate and tissue damage within the anterior and posterior eye segments.

Results

Exposure to zymosan resulted in the predicted arthritic, sexually dimorphic phenotype in SKG mice. The eyes of SKG mice exhibited episodic intravascular cellular responses to zymosan or curdlan as indicated by significant increases in leukocyte–endothelium interactions akin to ocular vasculitis. However, despite the significant increase in early cell-trafficking responses, cellular infiltration into the iris stroma was not observed and histopathological signs indicative of a sustained uveitis were absent. Instead, eyes of SKG mice developed blepharoconjunctivitis that coincided with arthritis and exhibited sexual dimorphism.

Conclusions

This study underscores the complexity surrounding the pathogenesis of uveitis and its relationship with arthritis. The findings suggest that distinct mechanisms exist by which pathogenic autoimmune T cells target the eyes versus joints, which likely involves the environmental context but nonetheless should be taken into account in the identification and development of effective therapies for each organ.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0725-z) contains supplementary material, which is available to authorized users.

Genetic dissection of acute anterior uveitis reveals similarities and differences in associations observed with ankylosing spondylitis

OBJECTIVE

To use high-density genotyping to investigate the genetic associations of acute anterior uveitis (AAU) in patients with and those without ankylosing spondylitis (AS).

METHODS

We genotyped samples from 1,711 patients with AAU (either primary or combined with AS), 2,339 AS patients without AAU, and 10,000 control subjects on an Illumina Immunochip Infinium microarray. We also used data for AS patients from previous genome-wide association studies to investigate the AS risk locus ANTXR2 for its putative effect in AAU. ANTXR2 expression in mouse eyes was investigated by real-time quantitative reverse transcription-polymerase chain reaction.

RESULTS

A comparison between all patients with AAU and healthy control subjects showed strong association over HLA-B, corresponding to the HLA-B27 tag single-nucleotide polymorphism rs116488202. The association of 3 non-major histocompatibility complex loci, IL23R, the intergenic region 2p15, and ERAP1, reached genome-wide significance (P < 5 × 10(-8)). Five loci harboring the immune-related genes IL10-IL19, IL18R1-IL1R1, IL6R, the chromosome 1q32 locus harboring KIF21B, as well as the eye-related gene EYS, were also associated, reaching a suggestive level of significance (P < 5 × 10(-6)). Several previously confirmed AS associations demonstrated significant differences in effect size between AS patients with AAU and AS patients without AAU. ANTXR2 expression varied across eye compartments.

CONCLUSION

These findings of both novel AAU-specific associations and associations shared with AS demonstrate overlapping but also distinct genetic susceptibility loci for AAU and AS. The associations in IL10 and IL18R1 are shared with inflammatory bowel disease, suggesting common etiologic pathways.

Acute anterior uveitis and other extra-articular manifestations of spondyloarthritis

BACKGROUND

Spondyloarthritis (SpA) is associated with an array of peripheral manifestations. Our study aims to evaluate extra-articular manifestations of SpA in a Romanian academic clinical setting and to observe their associations with different disease measures.

METHODS

The study was designed to note the extra-articular manifestations of SpA patients in a cross-sectional and retrospective manner. Records included demographics, inflammation markers, SpA clinical characteristics, treatment regimes, associated osteoporosis and cardiovascular morbidity. Data were assessed by using appropriate non-parametric tests.

RESULTS

A total of 126 SpA patients were included. The most common extra-articular manifestations were skin involvement in the form of psoriasis (34.1%), eye involvement in the form of acute anterior uveitis (8.7%) and dactylitis (7.2%). Compared to patients with no record of uveitis, uveitis-affected cases were more frequently males, more frequently diagnosed with ankylosing spondylitis, but less frequently dyslipidemic and diagnosed with psoriasis. Psoriasis-affected patients were older and had a higher prevalence of peripheral SpA diagnosis, but a lower prevalence of radiographic sacroiliitis.

CONCLUSIONS

Acute anterior uveitis in SpA predominantly affects males with AS. This is relevant both to clinical and fundamental science, since its management requires both ophthalmology and rheumatology clinical settings. Psoriasis was associated more frequently with peripheral SpA.

ABBREVIATIONS

AHT = arterial hypertension, AS = ankylosing spondylitis, ASAS = Assessment in SpondyloArthritis international Society, aSpA = axial spondyloarthritis, BASFI = Bath Ankylosing Spondylitis Functional Index, BASDAI = Bath Ankylosing Spondylitis Disease Activity Index, CRP = C-reactive protein, ESR = erythrocyte sedimentation rate, DM2 = type 2 diabetes mellitus, HLA = human leukocyte antigen, IBD = inflammatory bowel disease, MRI = magnetic resonance imaging, mSpA = mixed (peripheral and axial) spondyloarthritis, NSAIDs = non-steroidal anti-inflammatory drugs, pSpA = peripheral spondyloarthritis, PsA = psoriatic arthritis, ReA = reactive arthritis, SD = standard deviation, SI = sacroiliitis, SpA = spondyloarthritis, UDSpA = undifferentiated spondyloarthritis.

Autoimmune uveitis: a retrospective analysis of 104 patients from a tertiary reference center

Background

The aim of this study was to identify the main features of a cohort of Caucasian patients with idiopathic (I) and systemic disease-associated (SDA) autoimmune uveitis (AU) who were followed up at a single tertiary reference center. The study consisted of a retrospective analysis of the demographic, clinical, and laboratory features and the response to treatment of 104 patients with AU evaluated between 2004 and 2013, with a median follow-up of 4.8 years. The primary outcome measure was the response to systemic treatment after 24 months of therapy. The data are expressed as the range, percentage, or mean ± standard error. Categorical variables were assessed by Fisher's exact test.

Results

The mean age at diagnosis was 40.1 ± 17.8 years for men and 44.1 ± 15.3 years for women. There was a slight female predominance. Of the 104 patients, 72.1% had I-AU and 27.9% SDA-AU. The most frequent associations were with ankylosing spondyloarthritis, autoimmune thyroiditis, inflammatory bowel diseases, and Behcet's disease. Symptoms at presentation consisted of eye redness and pain (28.8%), decreased visual acuity (25.9%), and floaters (18.3%). Complications included cataracts (24%), retinal neovascularization (16.3%), chorio-retinal scars (10.6%), cystoid macular edema (8.6%), glaucoma/ocular hypertension (7.7%), epiretinal membranes (4.8%), and retinal detachment (3.8%). The prevalence of autoantibodies, mostly antinuclear antibodies, was comparable between the I-AU and SDA-AU groups. Fisher's exact test showed a direct correlation between patients with class I HLA B27, Cw8, B5 (51, 52), B51, or Cw2 and the presence of AU, whereas among patients with class II HLA, only DQ1 was a predisposing factor for AU. The therapeutic spectrum included corticosteroids and immunosuppressive agents, given either alone or in various combinations according to the severity of AU and the extent of the clinical response. Among the immunosuppressive drugs, azathioprine was preferentially used for anterior uveitis, and cyclosporine-A for intermediate and posterior uveitis. An assessment of the patients after 24 months of therapy showed a complete remission in 43.3% and a significant clinical improvement in 26.9%.

Conclusions

At our tertiary reference center, the prevalence in Caucasian patients of I-AU was approximately 2.5-fold higher than that of SDA-AU. Our findings point to the need for a patient-tailored therapeutic approach according to the anatomic site and the severity of AU. Therapy should be prolonged, over a period of months and even up to 1–2 years, in order to achieve stable control of the disease and to prevent severe complications. The outcome of SDA-AU is also influenced by treatment of the underlying systemic disease. Additional controlled trials are needed to assess the efficacy and the long-term safety of both the prescribed therapeutic agents and their combinations.

Uveitis is associated with hypertension and atherosclerosis in patients with ankylosing spondylitis: a cross-sectional study

OBJECTIVES

Uveitis is the most common extra-articular manifestation in patients with ankylosing spondylitis (AS), but the literature describing AS patients with a history of uveitis is limited. The objective was to examine if a history of uveitis in patients with AS is associated with increased disease activity and functional impairment and to investigate whether uveitis is associated with an increased frequency of cardiovascular comorbidities, defined here as hypertension and atherosclerosis.

METHODS

Data were recorded cross-sectionally through patient interviews, blood samples, clinical examination, and questionnaires. Carotid plaques were identified by ultrasonography. AS disease activity and function were compared across categories of uveitis using ANCOVA analyses. Associations between uveitis and hypertension and atherosclerosis [atherosclerotic cardiovascular disease (CVD) and/or carotid plaque] were analyzed in multivariate logistic regression models.

RESULTS

Of 159 patients with AS (61.6% male, mean age 50.5 years), 84 (52.8%) had experienced one or more episodes of uveitis. AS disease activity was higher in patients with a history of uveitis, statistically significant for functional impairment [Bath AS Functional Index (BASFI)] [mean difference (95% CI)] lnBASFI = 0.2 (0.0-0.3), p = 0.05. Patients with uveitis had an increased odds ratio [OR (95% CI)] for hypertension [3.29 (1.29-8.41), p = 0.01] and atherosclerosis [2.57 (1.15-5.72), p = 0.02].

CONCLUSIONS

AS patients with a history of uveitis had non-significantly higher disease activity and significantly higher functional impairment. A history of uveitis was associated with hypertension as well as atherosclerosis. These results may be important in identifying AS patients with elevated risk of CVD but should be confirmed in longitudinal cohorts.

The challenges, advantages and future of phenome-wide association studies

Over the last decade, significant technological breakthroughs have revolutionized human genomic research in the form of genome-wide association studies (GWASs). GWASs have identified thousands of statistically significant genetic variants associated with hundreds of human conditions including many with immunological aetiologies (e.g. multiple sclerosis, ankylosing spondylitis and rheumatoid arthritis). Unfortunately, most GWASs fail to identify clinically significant associations. Identifying biologically significant variants by GWAS also presents a challenge. The GWAS is a phenotype-to-genotype approach. As a complementary/alternative approach to the GWAS, investigators have begun to exploit extensive electronic medical record systems to conduct a genotype-to-phenotype approach when studying human disease – specifically, the phenome-wide association study (PheWAS). Although the PheWAS approach is in its infancy, this method has already demonstrated its capacity to rediscover important genetic associations related to immunological diseases/conditions. Furthermore, PheWAS has the advantage of identifying genetic variants with pleiotropic properties. This is particularly relevant for HLA variants. For example, PheWAS results have demonstrated that the HLA-DRB1 variant associated with multiple sclerosis may also be associated with erythematous conditions including rosacea. Likewise, PheWAS has demonstrated that the HLA-B genotype is not only associated with spondylopathies, uveitis, and variability in platelet count, but may also play an important role in other conditions, such as mastoiditis. This review will discuss and compare general PheWAS methodologies, describe both the challenges and advantages of the PheWAS, and provide insight into the potential directions in which PheWAS may lead.

Does spinal MRI add incremental diagnostic value to MRI of the sacroiliac joints alone in patients with non-radiographic axial spondyloarthritis?

Objective

To assess the incremental diagnostic value of spine MRI evaluated separately from and combined with sacroiliac joint (SIJ) MRI in non-radiographic axial spondyloarthritis (nr-axSpA) compared with SIJ MRI alone.

Methods

The study sample comprised two independent cohorts A/B of 130 consecutive patients aged ≤50 years with back pain, newly referred to two university clinics, and 20 healthy controls. Patients were classified according to clinical examination and pelvic radiographs as having nr-axSpA (n=50), ankylosing spondylitis (n=33), or non-specific back pain (n=47). Four readers assessed SIJ and spine MRI separately 6 months apart, and 1–12 months later both scans simultaneously using standardised modules. Readers recorded presence/absence of SpA and their level of confidence in this conclusion on a 0–10 scale (0=definitely not; 10=definite). We analysed differences between SIJ MRI versus spine MRI alone, and SIJ MRI alone versus combined MRI, descriptively by the number/percentage of subjects according to the mean of four readers.

Results

In cohorts A/B, 15.8%/24.2% of patients with nr-axSpA having a negative SIJ MRI were reclassified as being positive for SpA by global evaluation of combined scans. However, 26.8%/11.4% of non-specific back pain controls and 17.5% of healthy volunteers with a negative SIJ MRI were falsely reclassified as having SpA by combined MRI. Low confidence in a diagnosis of SpA by SIJ MRI increased to high confidence by combined MRI in 6.6%/7.3% of patients with nr-axSpA.

Conclusions

Combined spine and SIJ MRI added little incremental value compared with SIJ MRI alone for diagnosing patients with nr-axSpA and enhancing confidence in this diagnosis.

Fat infiltration on magnetic resonance imaging of the sacroiliac joints has limited diagnostic utility in nonradiographic axial spondyloarthritis

OBJECTIVE

To explore whether morphological features of fat infiltration (FI) on sacroiliac joint (SIJ) magnetic resonance imaging (MRI) contribute to diagnostic utility in 2 inception cohorts of patients with nonradiographic axial spondyloarthritis (nr-axSpA).

METHODS

Four blinded readers assessed SIJ MRI in 2 cohorts (A/B) of 157 consecutive patients with back pain who were ≤ 50 years old, and in 20 healthy controls. Patients were classified according to clinical examination and pelvic radiography as having nr-axSpA (n = 51), ankylosing spondylitis (n = 34), or nonspecific back pain (n = 72). Readers recorded FI, bone marrow edema (BME), and erosion, predefined morphological features of FI (distinct border, homogeneity, subchondral location), and anatomical distribution of SIJ FI. The proportion of SIJ quadrants affected by FI and frequencies of various SIJ FI features were analyzed descriptively. We calculated positive/negative likelihood ratios (LR) to estimate the diagnostic utility of various features of FI, with and without associated BME, and erosion.

RESULTS

Of the patients with nr-axSpA in cohorts A/B, 45.0%/48.4% had FI in ≥ 2 SIJ quadrants. Of those, 25.0%/22.6% and 20.0%/25.8% showed FI with distinct border or homogeneous pattern, respectively, and 50% to 100% of those patients displayed concomitant BME or erosion. FI per se in ≥ 2 SIJ quadrants had no diagnostic utility (LR+ 1.62/1.91). FI with distinct border (LR+ 8.29/2.13) or homogeneity (LR+ 6.24/3.78) demonstrated small to moderate diagnostic utility.

CONCLUSION

SIJ FI per se was not of clinical utility in recognition of nr-axSpA. Distinct border or homogeneity of FI on SIJ MRI showed small to moderate diagnostic utility in nr-axSpA, but were strongly associated with concomitant BME or erosion, highlighting the contextual interpretation of SIJ MRI.

Genetics of ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory arthritis that affects the spine and sacroiliac joints. It causes significant disability and is associated with a number of other features including peripheral arthritis, anterior uveitis, psoriasis and inflammatory bowel disease (IBD). Significant progress has been made in the genetics of AS have in the last five years, leading to new treatments in trial, and major leaps in understanding of the aetiopathogenesis of the disease.

IL23R gene confers susceptibility to ankylosing spondylitis concomitant with uveitis in a Han Chinese population

Purpose

The interleukin-23 receptor (IL-23R) has been shown to be associated with ankylosing spondylitis (AS) in many different populations. This study examined whether IL-23R polymorphisms were associated with susceptibility to this disease in a Chinese Han population.

Methods

Three single-nucleotide polymorphisms (SNP), rs7517847, rs11209032, and rs17375018, were genotyped in 291 AS patients and 312 age-, sex-, and ethnically matched healthy controls using a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) assay.

Results

The genotype and allele frequencies of rs17375018, rs7517847, and rs11209032 were not different between the patients with AS and the healthy controls. On the one hand, stratification analysis indicated that the rs17375018 GG genotype and the G allele were increased in AS patients who were HLA-B27 positive (corrected p = 0.024, odds ratio [OR] 2.35, 95% CI 1.30–4.24; p_c = 0.006, OR 1.98, 95% CI 1.28–3.07, respectively). On the other hand, the analysis according to clinical characteristics showed a significantly increased prevalence of the homozygous rs17375018 GG genotype and the G allele in patients with AS and uveitis compared with the controls (p_c = 0.024 and p_c = 0.024, respectively). In addition, haplotype analysis performed with the SHEsis platform revealed no significant difference concerning the haplotypes between AS patients and healthy controls.

Conclusions

In this study, the results suggested that the rs17375018 of IL23R was positively associated with HLA-B27-positive AS and that the rs17375018 GG of IL-23R was associated with AS concomitant with uveitis. We found no evidence for an association between the other two SNPs of IL-23R and AS.

[Human leukocyte antigen (HLA) system in ophthalmology]

Various inflammatory and non-inflammatory eye diseases are associated with specific HLA isotypes. Therefore, HLA isotyping can be a useful diagnostic tool for these diseases and has already been shown to reduce the rejection rate of corneal allografts. Unfortunately, the volume of published data and the varying quality of these publications complicate obtaining good overview in this field. This review briefly summarizes the genetic structure of the HLA system and elucidates differences between HLA classes I and II in the context of antigen presentation. Possible mechanisms of HLA associations in the field of ophthalmology are discussed, and finally different tools (e.g. genome wide association studies) for assessing associations of HLA isotypes with different ocular diseases are examined.

Association between polymorphism of the vitamin D metabolism gene CYP27B1 and HLA-B27-associated uveitis. Is a state of relative immunodeficiency pathogenic in HLA B27-positive uveitis?

Objective

Polymorphisms of the vitamin D metabolism gene CYP27B1 showed associations with multiple autoimmune diseases. The aim of this study was to investigate a possible association between the rs703842 A>G polymorphism of the CYP27B1 gene and HLA-B27-associated uveitis.

Design

One hundred fifty-nine patients with HLA-B27-associated uveitis, 138 HLA-B27-negative controls and 100 HLA-B27-positive controls were recruited for this retrospective case-control study. Main outcome parameters were genotype distribution and allelic frequencies determined by polymerase chain reaction.

Results

Carriers of the rs703842G allele were found significantly more often in patients with HLA-B27-associated uveitis than in HLA-B27-positive controls (p = 0.03). Between patients and HLA-B27-negative controls no significant difference in the genotype distribution of the rs703842 A>G polymorphism was found (p = 0.97).

Conclusions

Our data suggest that the rs703842 A>G polymorphism may play a role in HLA-B27-associated uveitis.