Predicting uveitis in juvenile idiopathic arthritis: from biomarkers to clinical practice

Candidate Tear-Based Uveitis Biomarkers in Children with JIA Based on Arthritis Activity and Topical Corticosteroid Use

BACKGROUND

Uveitis is an inflammatory ocular disease secondary to disruption of the retinal pigmented epithelium (RPE) and blood retinal barrier (BRB). Known clinical factors do not accurately predict uveitis risk in Juvenile Idiopathic Arthritis (JIA). Tear fluid is easily obtained for biomarker study. We aim to identify tear-based markers associated with the presence of uveitis in children with JIA.

METHODS

In a cross-sectional comparative cohort study, tears were collected by Schirmer strips from children with oligoarticular JIA-associated uveitis (JIA-U) and JIA without uveitis (JIA-no-U). A tandem isotope tagging (iTRAQ and TMT) strategy was used for relative quantitation via nanoLC-MS/MS to quantify proteins in the affected eye. Log transformed relative protein abundance of protein levels was compared between groups using Wilcoxon exact test. We explored the influence of arthritis activity and topical corticosteroids (CS) use on protein levels. STRING analysis was performed.

RESULTS

Tear samples of 14 JIA-U and 14 JIA-no-U patients were analyzed. Thirteen proteins were differentially expressed between both groups. Stratified analysis based on arthritis activity (inactive arthritis) and topical CS (off CS) showed that alpha-2-macroglobulin (p = 0.012), apolipoprotein A1 (p = 0.036), S100A9 (p = 0.05), haptoglobin (p = 0.066), and transthyretin (p = 0.066) consistently differentiated between both groups. On STRING analysis, these proteins were associated with the RPE, BRB, and inflammation.

CONCLUSION

Importantly, we identified proteins involved in the RPE, BRB, and immune response that were differentially abundant in the tears of children with JIA-U compared to JIA-no-U, regardless of arthritis activity or topical CS. Candidate tear-based biomarkers may represent a non-invasive means to detect uveitis.

Management of JIA associated uveitis

Juvenile Idiopathic Arthritis (JIA) is the most common chronic rheumatic disease in childhood, and is associated with uveitis in up to 20-25% of cases. Typically, the uveitis is chronic, asymptomatic, non-granulomatous and anterior. For this reason, screening for uveitis is recommended to identify uveitis early and allow treatment to prevent sight-threatening complications. The management of JIA associated uveitis requires a multidisciplinary approach and a close collaboration between paediatric rheumatologist and ophthalmologist. Starting the appropriate treatment to control uveitis activity and prevent ocular complications is crucial. Current international recommendations advise a step-wise approach, starting with methotrexate and moving on to adalimumab if methotrexate alone is not sufficient to control the disease. If the uveitis remains active despite standard treatment other therapeutic options may be considered including anti-IL6 or other anti-TNF agents such as infliximab, although the evidence for these agents is limited.

A clearer vision: insights into juvenile idiopathic arthritis-associated uveitis

The aim of this narrative review is to synthesize existing evidence-based knowledge on juvenile idiopathic arthritis-associated uveitis (JIA-U). We highlight epidemiology, pathophysiology, causes and genetics, risk factors, clinical features, diagnosis and screening, laboratory biomarkers, treatment options, trials with recent advances, and research challenges pertaining to JIA-U. The prevalence of JIA-U varies with different JIA subtypes, most frequently associated with the oligoarticular subtype. The risk factors involved in the development of JIA-U include younger age, antinuclear antibody (ANA) positivity, and the oligoarticular subtype of JIA, along with some specific major histocompatibility complex genes. Certain laboratory biomarkers, such as ANA, rheumatoid factor, interferon-λ, erythrocyte sedimentation rate, and transthyretin, have been used in JIA-U diagnosis, progress monitoring, and prognostication. Clinical features of JIA-U can range from asymptomatic to ophthalmic symptoms like redness, blurred vision, decreased visual acuity, hypopyon, and posterior uveitis, which can lead to retinal detachment and macular edema. The management protocol involves topical and systemic steroids, cycloplegics, disease-modifying antirheumatic drugs, biologic drugs, and surgical options. Early detection combined with prompt treatment is crucial to preventing irreversible vision loss in JIA-U.

Uveitis Associated with Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is the most common cause of uveitis in children. While symptoms are usually mild, persistent eye inflammation could lead to severe complications and impaired vision. It is essential that JIA patients at risk are diagnosed with uveitis early, receive adequate treatment, and avoid developing complications, such as cataract, glaucoma, and amblyopia. The purpose of this mini-review is to summarize the screening strategies and clinical management for JIA-associated uveitis (JIA-U) as well as the current state of molecular markers linked to this condition. Because glaucoma is one of the most common causes of visual loss in JIA-U, special focus will be put on this serious complication. We conclude by describing the current evidence regarding the long-standing question of whether chronic anterior uveitis without arthritis may be the same disease entity as JIA-U.

Challenges and management of childhood non-infectious chronic uveitis

INTRODUCTION

Childhood uveitis is a sight-threatening condition, because if not properly recognized and treated can lead to several ocular complications and blindness. It represents a real challenge not only from an etiologic/diagnostic point of view, but also for management and therapy.

AREAS COVERED

In this review we will discuss the main etiologies, the diagnostic approach, risk factors associated to childhood non-infectious uveitis (cNIU), and the difficulties in eye examination in childhood. Moreover, we will discuss the treatment of cNIU in term of therapeutic choice, timing of initiation and withdrawal.

EXPERT OPINION

Identification of specific diagnosis is mandatory to prevent severe complications, thus a thorough differential diagnosis is essential. Pediatric eye examination may be extremely challenging due to the scarce collaboration, but novel techniques and biomarkers will help in identify low grade of inflammation, eventually modify long-term outcomes. Once identified the appropriate diagnosis, recognition of children who may benefit of a systemic treatment is crucial. What, When and how long are the key questions to address in this field. Current evidence and future results of ongoing clinical trials will help in driving treatment. A proper ocular screening, not only in the context of systemic disease, should be discussed by experts.

Study of the shared gene signatures of polyarticular juvenile idiopathic arthritis and autoimmune uveitis

Objective

To explore the shared gene signatures and potential molecular mechanisms of polyarticular juvenile idiopathic arthritis (pJIA) and autoimmune uveitis (AU).

Method

The microarray data of pJIA and AU from the Gene Expression Omnibus (GEO) database were downloaded and analyzed. The GEO2R tool was used to identify the shared differentially expressed genes (DEGs) and genes of extracellular proteins were identified among them. Then, weighted gene co-expression network analysis (WGCNA) was used to identify the shared immune-related genes (IRGs) related to pJIA and AU. Moreover, the shared transcription factors (TFs) and microRNAs (miRNAs) in pJIA and AU were acquired by comparing data from HumanTFDB, hTFtarget, GTRD, HMDD, and miRTarBase. Finally, Metascape and g: Profiler were used to carry out function enrichment analyses of previously identified gene sets.

Results

We found 40 up-regulated and 15 down-regulated shared DEGs via GEO2R. Then 24 shared IRGs in positivity-related modules, and 18 shared IRGs in negatively-related modules were found after WGCNA. After that, 3 shared TFs (ARID1A, SMARCC2, SON) were screened. And the constructed TFs-shared DEGs network indicates a central role of ARID1A. Furthermore, hsa-miR-146 was found important in both diseases. The gene sets enrichment analyses suggested up-regulated shared DEGs, TFs targeted shared DEGs, and IRGs positivity-correlated with both diseases mainly enriched in neutrophil degranulation process, IL-4, IL-13, and cytokine signaling pathways. The IRGs negatively correlated with pJIA and AU mainly influence functions of the natural killer cell, cytotoxicity, and glomerular mesangial cell proliferation. The down-regulated shared DEGs and TFs targeted shared DEGs did not show particular functional enrichment.

Conclusion

Our study fully demonstrated the flexibility and complexity of the immune system disorders involved in pJIA and AU. Neutrophil degranulation may be considered the shared pathogenic mechanism, and the roles of ARID1A and MiR-146a are worthy of further in-depth study. Other than that, the importance of periodic inspection of kidney function is also noteworthy.

Development and External Validation of a Model Predicting New-Onset Chronic Uveitis at Different Disease Durations in Juvenile Idiopathic Arthritis

OBJECTIVE

To develop and externally validate a prediction model for new-onset chronic uveitis in children with juvenile idiopathic arthritis (JIA) for clinical application.

METHODS

Data from the international Pharmachild registry were used to develop a multivariable Cox proportional hazards model. Predictors were selected by backward selection, and missing values were handled by multiple imputation. The model was subsequently validated and recalibrated in 2 inception cohorts: the UK Childhood Arthritis Prospective Study (CAPS) study and the German Inception Cohort of Newly diagnosed patients with juvenile idiopathic arthritis (ICON) study. Model performance was evaluated by calibration plots and C statistics for the 2-, 4-, and 7-year risk of uveitis. A diagram and digital risk calculator were created for use in clinical practice.

RESULTS

A total of 5,393 patients were included for model development, and predictor variables were age at JIA onset (hazard ratio [HR] 0.83 [95% confidence interval (95% CI) 0.77-0.89]), ANA positivity (HR 1.59 [95% CI 1.06-2.38]), and International League of Associations for Rheumatology category of JIA (HR for oligoarthritis, psoriatic arthritis, and undifferentiated arthritis versus rheumatoid factor-negative polyarthritis 1.40 [95% CI 0.91-2.16]). Performance of the recalibrated prediction model in the validation cohorts was acceptable; calibration plots indicated good calibration and C statistics for the 7-year risk of uveitis (0.75 [95% CI 0.72-0.79] for the ICON cohort and 0.70 [95% CI 0.64-0.76] for the CAPS cohort).

CONCLUSION

We present for the first time a validated prognostic tool for easily predicting chronic uveitis risk for individual JIA patients using common clinical parameters. This model could be used by clinicians to inform patients/parents and provide guidance in choice of uveitis screening frequency and arthritis drug therapy.

Sex differences in musculoskeletal injury and disease risks across the lifespan: Are there unique subsets of females at higher risk than males for these conditions at distinct stages of the life cycle?

Sex differences have been reported for diseases of the musculoskeletal system (MSK) as well as the risk for injuries to tissues of the MSK system. For females, some of these occur prior to the onset of puberty, following the onset of puberty, and following the onset of menopause. Therefore, they can occur across the lifespan. While some conditions are related to immune dysfunction, others are associated with specific tissues of the MSK more directly. Based on this life spectrum of sex differences in both risk for injury and onset of diseases, a role for sex hormones in the initiation and progression of this risk is somewhat variable. Sex hormone receptor expression and functioning can also vary with life events such as the menstrual cycle in females, with different tissues being affected. Furthermore, some sex hormone receptors can affect gene expression independent of sex hormones and some transitional events such as puberty are accompanied by epigenetic alterations that can further lead to sex differences in MSK gene regulation. Some of the sex differences in injury risk and the post-menopausal disease risk may be "imprinted" in the genomes of females and males during development and sex hormones and their consequences only modulators of such risks later in life as the sex hormone milieu changes. The purpose of this review is to discuss some of the relevant conditions associated with sex differences in risks for loss of MSK tissue integrity across the lifespan, and further discuss several of the implications of their variable relationship with sex hormones, their receptors and life events.

Pediatric uveitis: Role of the pediatrician

The challenges of childhood uveitis lie in the varied spectrum of its clinical presentation, the often asymptomatic nature of disease, and the evolving nature of the phenotype alongside normal physiological development. These issues can lead to delayed diagnosis which can cause significant morbidity and severe visual impairment. The most common ocular complications include cataracts, band keratopathy, glaucoma, and macular oedema, and the various associated systemic disorders can also result in extra-ophthalmic morbidity. Pediatricians have an important role to play. Their awareness of the various presentations and etiologies of uveitis in children afford the opportunity of prompt diagnosis before complications arise. Juvenile Idiopathic Arthritis (JIA) is one of the most common associated disorders seen in childhood uveitis, but there is a need to recognize other causes. In this review, different causes of uveitis are explored, including infections, autoimmune and autoinflammatory disease. As treatment is often informed by etiology, pediatricians can ensure early ophthalmological referral for children with inflammatory disease at risk of uveitis and can support management decisions for children with uveitis and possible underling multi-system inflammatory disease, thus reducing the risk of the development of irreversible sequelae.

Novel biomarkers for prediction of outcome and therapeutic response in juvenile idiopathic arthritis

INTRODUCTION

The search for biomarkers in juvenile idiopathic arthritis (JIA) is a promising and rapidly expanding field of investigation. The biomarkers identified so far may help to dissect the clinical heterogeneity of the illness, measure the level of disease activity, predict clinical remission, relapse, response to medications, course over time, complications, and forestall disease flares.

AREAS COVERED

We provide a summary of the most recent advances in the development and application of biomarkers in JIA. We performed a PubMed search for significant articles combining predetermined keywords related to biomarkers in non-systemic and systemic JIA, chronic uveitis, and macrophage activation syndrome (MAS). The biomarkers available or under study are presented and discussed separately for non-systemic and systemic subtypes and for the two main disease complications, uveitis and MAS.

EXPERT OPINION

The incorporation of valid and reliable biomarkers in standard clinical care may help to design better patient-tailored treatment regimens and to improve the therapeutic strategies based on the treat-to-target approach. The establishment of biomarkers that predict the risk of disease flare may lead to define the optimal modalities for treatment discontinuation after the achievement of clinical remission.

Next-Generation HLA Sequence Analysis Uncovers Shared Risk Alleles Between Clinically Distinct Forms of Childhood Uveitis

Purpose

Classical alleles of the human leukocyte antigen (HLA) complex have been linked to specific entities of pediatric noninfectious uveitis, yet genetic predisposition encoded by the HLA super-locus across the patient population remains understudied.

Methods

We performed next-generation full-length sequencing of HLA-A, HLA-B, HLA-C, HLA-DPB1, HLA-DQB1, and HLA-DRB1 in 280 cases. Dense genotype data from 499 Dutch controls from Genome of the Netherlands were imputed using an HLA-specific reference panel (n = 5225 samples from European ancestry). Cases and controls were compared using logistic regression models adjusting for sex.

Results

In total, 179 common and rare alleles were detected. Considering all cases and controls, HLA-DQB1*04:02 and HLA-DRB1*08:01 were identified as the principal HLA association, which was mainly driven by 92 cases with juvenile idiopathic arthritis-associated uveitis (JIA-U). The HLA-DQB1*04:02-HLA-DRB1*08:01 haplotype was also the primary association for the phenotypically similar idiopathic chronic anterior uveitis without arthritis (CAU). Also, HLA-DQB1*05:03 was an independent risk allele for CAU, but not in JIA-U. Analysis of 185 cases with other forms of uveitis revealed HLA-wide associations (P < 2.79 × 10⁻⁴) for HLA-DRB1*01:02, HLA-DRB1*04:03, and HLA-DQB1*05:03, which could be primarily attributed to cases with panuveitis. Finally, amino acid substitution modeling revealed that aspartic acid at position 57 that distinguishes the risk allele HLA-DQB1*05:03 (for CAU and panuveitis) from nonrisk alleles, significantly increased the binding capacity of naturally presented ligands to HLA-DQ.

Conclusions

These results uncovered novel shared HLA associations among clinically distinct phenotypes of pediatric uveitis and highlight genetic predisposition affecting the antigen presentation pathway.

Pediatric uveitis: A comprehensive review

Pediatric uveitis accounts for 5-10% of all uveitis. Uveitis in children differs from adult uveitis in that it is commonly asymptomatic and can become chronic and cause damage to ocular structures. The diagnosis might be delayed for multiple reasons, including the preverbal age and difficulties in examining young children. Pediatric uveitis may be infectious or noninfectious in etiology. The etiology of noninfectious uveitis is presumed to be autoimmune or autoinflammatory. The most common causes of uveitis in this age group are idiopathic and juvenile idiopathic arthritis-associated uveitis. The stepladder approach for the treatment of pediatric uveitis is based on expert opinion and algorithms proposed by multidisciplinary panels. Uveitis morbidities in pediatric patients include cataract, glaucoma, and amblyopia. Pediatric patients with uveitis should be frequently examined until remission is achieved. Once in remission, the interval between follow-up visits can be extended; however, it is recommended that even after remission the child should be seen every 8-12 weeks depending on the history of uveitis and the medications used. Close follow up is also necessary as uveitis can flare up during immunomodulatory therapy. It is crucial to measure the impact of uveitis, its treatment, and its complications on the child and the child's family. Visual acuity can be considered as an acceptable criterion for assessing visual function. Additionally, the number of cells in the anterior chamber can be a measure of disease activity. We review different aspects of pediatric uveitis. We discuss the mechanisms of noninfectious uveitis, including autoimmune and autoinflammatory etiologies, and the risks of developing uveitis in children with systemic rheumatologic diseases. We address the risk factors for developing morbidities, the Standardization of Uveitis Nomenclature (SUN) criteria for timing and anatomical classifications, and describe a stepladder approach in the treatment of pediatric uveitis based on expert opinion and algorithms proposed by multi-disciplinary panels. In this review article, We describe the most common entities for each type of anatomical classification and complications of uveitis for the pediatric population. Additionally, we address monitoring of children with uveitis and evaluation of Quality of Life.

A clinical prediction model for estimating the risk of developing uveitis in patients with juvenile idiopathic arthritis

OBJECTIVE

To build a prediction model for uveitis in children with JIA for use in current clinical practice.

METHODS

Data from the international observational Pharmachild registry were used. Adjusted risk factors as well as predictors for JIA-associated uveitis (JIA-U) were determined using multivariable logistic regression models. The prediction model was selected based on the Akaike information criterion. Bootstrap resampling was used to adjust the final prediction model for optimism.

RESULTS

JIA-U occurred in 1102 of 5529 JIA patients (19.9%). The majority of patients that developed JIA-U were female (74.1%), ANA positive (66.0%) and had oligoarthritis (59.9%). JIA-U was rarely seen in patients with systemic arthritis (0.5%) and RF positive polyarthritis (0.2%). Independent risk factors for JIA-U were ANA positivity [odds ratio (OR): 1.88 (95% CI: 1.54, 2.30)] and HLA-B27 positivity [OR: 1.48 (95% CI: 1.12, 1.95)] while older age at JIA onset was an independent protective factor [OR: 0.84 (9%% CI: 0.81, 0.87)]. On multivariable analysis, the combination of age at JIA onset [OR: 0.84 (95% CI: 0.82, 0.86)], JIA category and ANA positivity [OR: 2.02 (95% CI: 1.73, 2.36)] had the highest discriminative power among the prediction models considered (optimism-adjusted area under the receiver operating characteristic curve = 0.75).

CONCLUSION

We developed an easy to read model for individual patients with JIA to inform patients/parents on the probability of developing uveitis.

Structural Endpoints and Outcome Measures in Uveitis

Most uveitis entities are rare diseases but, taken together, are responsible for 5-10% of worldwide visual impairment which largely affects persons of working age. As with many rare diseases, there is a lack of high-level evidence regarding its clinical management, partly due to a dearth of reliable and objective quantitative endpoints for clinical trials. This review provides an overview of available structural outcome measures for uveitis disease activity and damage in an anatomical order from the anterior to the posterior segment of the eye. While there is a multitude of available structural outcome measures, not all might qualify as endpoints for clinical uveitis trials, and thorough testing of applicability is warranted. Furthermore, a consensus on endpoint definition, standardization, and "core outcomes" is required. As stipulated by regulatory agencies, endpoints should be precisely defined, clinically important, internally consistent, reliable, responsive to treatment, and relevant for the respective subtype of uveitis. Out of all modalities used for assessment of the reviewed structural outcome measures, optical coherence tomography, color fundus photography, fundus autofluorescence, and fluorescein/indocyanine green angiography represent current "core modalities" for reliable and objective quantification of uveitis outcome measures, based on their practical availability and the evidence provided so far.

Monitoring and Treatment of Juvenile Idiopathic Arthritis-associated Uveitis: Brazilian Evidence-based Practice Guidelines

Purpose: To present a national guideline for ophthalmologic care and surveillance of juvenile idiopathic arthritis-associated uveitis (JIA-uveitis).Methods: Review article based on medical literature and the experience of an Expert Committee composed of members of the Brazilian Society of Pediatric Ophthalmology/Brazilian Council of Ophthalmology and the Brazilian Society of Pediatrics/Brazilian Society of Rheumatology. Studies with a high level of evidence were selected by searching the PubMed/Medline database. The final document was approved by the experts.Results: The main recommendations are that children/adolescents with JIA should undergo screening according to their risk factors. Ophthalmological checkups should also consider ocular inflammation and therapy. Topical glucocorticoids should be the first line of therapy, with systemic glucocorticoids acting as bridge treatments in severe uveitis. Methotrexate should be the first-line systemic therapy and anti-tumor necrosis factor (anti-TNF alpha) the second for uncontrolled uveitis.Conclusions: This evidence-based guideline for JIA-uveitis will be useful for both ophthalmology and rheumatology practice.

Update on noninfectious uveitis in children and its treatment

PURPOSE OF REVIEW

To give an overview of recently published articles covering risk factors, novel biomarkers and treatment for noninfectious uveitis in children.

RECENT FINDINGS

In the last few years, several genetic markers, serum biomarkers, aqueous humor markers, tear biomarkers and clinical factors have been identified, which are associated with childhood noninfectious uveitis. We describe the most important reports in this field that may help to tailor the screening and monitoring of this population in the future and might become the target of novel therapies. The advances in the biologic therapy of paediatric uveitis, thanks to evidence provided by the SYCAMORE, ADJUVITE and APTITUDE trials, offer new possibilities for the treatment of patients who fail methotrexate with adalimumab and tocilizumab. We discuss the importance of comprehensive outcome measures as proposed by the Multinational Interdisciplinary Working Group for Uveitis in Childhood (MIWGUC).

SUMMARY

Paediatric noninfectious uveitis is a sight-threatening condition and the identification of risk factors and novel biomarkers is critical for tailored management. Biologic therapies are revolutionizing the outcomes of patients resistant to conventional therapy. Increasing our knowledge of disease pathogenesis is crucial to improve targeting of screening to those at highest risk and stratification of treatments.

Paediatric autoimmune and autoinflammatory conditions associated with uveitis

Childhood uveitis comprises a collection of heterogenous ocular phenotypes which are associated with a diverse range of childhood autoimmune and autoinflammatory disorders. Of these genetic and/or acquired disorders, juvenile idiopathic arthritis is the most common, affecting 30-80% of children with uveitis. Up to a third of children with uveitis have 'isolated' idiopathic disease and do not have an associated systemic disease which manifests in childhood. However, uveitis may be the presenting manifestation of disease; thus, the apparently well child who presents with uveitis may have isolated idiopathic disease, but they may have an evolving systemic disorder. The diagnosis of most of the associated disorders is reliant on clinical features rather than serological or genetic investigations, necessitating detailed medical history taking and systemic examination. Adequate control of inflammation is key to good visual outcomes, and multidisciplinary care is key to good broader health outcomes.

Whole Transcriptome Analysis Reveals Heterogeneity in B Cell Memory Populations in Patients With Juvenile Idiopathic Arthritis-Associated Uveitis

Purpose

Patients with juvenile idiopathic arthritis (JIA) are prone to developing chronic anterior uveitis (JIA-U+). Although several risk factors for JIA-U+ have been identified, the underlying etiology is poorly understood. Histopathological studies demonstrate B cell infiltrates in eye tissues of patients with JIA-U+.

Methods

We performed transcriptome profiling of peripheral blood CD19-positive B cells taken from 14 cases with JIA-U+, 13 JIA cases without uveitis (JIA-U-), and five healthy controls. Deconvolution-based estimation was used to determine the immune cell fractions for each sample.

Results

Deconvolution results revealed that naive B cells made up on average 71% of the CD19-positive cell fractions analyzed. Differential expression analysis identified 614 differentially expressed genes (DEGs) between the groups at nominal significance and six genes at a false discovery rate of 5% (FDR < 0.05). Head-to-head comparison of all JIA-U- versus JIA-U+ revealed no DEGs in the CD19+ B cell pool (FDR < 0.05). However, principal component analysis based on a panel of key genes for B cell subsets revealed that JIA-U+ cases bifurcate into distinct clusters, characterized by markedly disparate expression for genes associated with specific memory B cell populations. CIBERSORT analysis of the overall transcriptome of the new uveitis cluster identified an increased proportion of memory B cells.

Conclusion

These data show that JIA-U- and JIA-U+ have a globally similar transcriptome considering the global peripheral CD19-positive B cell pool. However, heterogeneity in B cell memory genes among cases with uveitis suggests a role for specific memory B cell subsets in the etiology of JIA-U+.

Can the CRP/albumin Ratio be Used as a New Indicator of Activation in Patients with Uveitis?

Purpose: To evaluate whether the C-reactive protein (CRP)/albumin ratio (CAR) in patients with uveitis during an attack is a marker that can give information about the activity, severity and prognosis of the disease.Methods: This study included 35 patients with an uveitis attack and 35 healthy volunteers. The localization and severity of uveitis were recorded. Patients' complete blood count (CBC) during the attack, CRP, CAR, erythrocyte sedimentation rate(ESR), neutrophil/lymphocyte ratio(NLR), and platelet/lymphocyte ratio(PLR) were recorded.Results: The mean age was 34.1 ± 12.5 years for the 35 uveitis cases and 30.1 ± 4.1 years for the healthy volunteers. CRP and CAR were significantly higher in uveitis patients (p = .015 and 0.011, respectively). While CRP and CAR were significantly higher in severe anterior uveitis than mild anterior uveitis (p = .036 and 0.022, respectively), only CAR was significantly higher in severe posterior and panuveitis than mild ones(p = .017).Conclusion: CAR may be an important parameter in determining the activation of the uveitis.

Validation of prediction models of severe disease course and non-achievement of remission in juvenile idiopathic arthritis: part 1-results of the Canadian model in the Nordic cohort

Background

Models to predict disease course and long-term outcome based on clinical characteristics at disease onset may guide early treatment strategies in juvenile idiopathic arthritis (JIA). Before a prediction model can be recommended for use in clinical practice, it needs to be validated in a different cohort than the one used for building the model. The aim of the current study was to validate the predictive performance of the Canadian prediction model developed by Guzman et al. and the Nordic model derived from Rypdal et al. to predict severe disease course and non-achievement of remission in Nordic patients with JIA.

Methods

The Canadian and Nordic multivariable logistic regression models were evaluated in the Nordic JIA cohort for prediction of non-achievement of remission, and the data-driven outcome denoted severe disease course. A total of 440 patients in the Nordic cohort with a baseline visit and an 8-year visit were included. The Canadian prediction model was first externally validated exactly as published. Both the Nordic and Canadian models were subsequently evaluated with repeated fine-tuning of model coefficients in training sets and testing in disjoint validation sets. The predictive performances of the models were assessed with receiver operating characteristic curves and C-indices. A model with a C-index above 0.7 was considered useful for clinical prediction.

Results

The Canadian prediction model had excellent predictive ability and was comparable in performance to the Nordic model in predicting severe disease course in the Nordic JIA cohort. The Canadian model yielded a C-index of 0.85 (IQR 0.83–0.87) for prediction of severe disease course and a C-index of 0.66 (0.63–0.68) for prediction of non-achievement of remission when applied directly. The median C-indices after fine-tuning were 0.85 (0.80–0.89) and 0.69 (0.65–0.73), respectively. Internal validation of the Nordic model for prediction of severe disease course resulted in a median C-index of 0.90 (0.86–0.92).

Conclusions

External validation of the Canadian model and internal validation of the Nordic model with severe disease course as outcome confirm their predictive abilities. Our findings suggest that predicting long-term remission is more challenging than predicting severe disease course.