Remission rate is not dependent on the presence of antinuclear antibodies in juvenile idiopathic arthritis

Juvenile idiopathic arthritis and its associated uveitis

INTRODUCTION

Juvenile idiopathic arthritis is the most common chronic rheumatologic disease in children. Uveitis is the most common extra-articular manifestation of JIA, and it can be a sight-threatening condition.

AREAS COVERED

In this review article, we discussed epidemiology, risk factors, clinical presentation, supportive laboratory tests, treatment options, and complications of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis associated uveitis. We covered conventional immunomodulatory therapy and biologic response modifiers agents for different types of Juvenile idiopathic arthritis and their associated uveitis. Finally, we discussed the course of disease, functional outcome, and the quality of life of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis-associated uveitis.

EXPERT OPINION

Although clinical outcomes of Juvenile idiopathic arthritis and its associated uveitis have been improved over the past three decades by biologic response modifier agents, a significant proportion of patients require active treatment into adult life therefore screening and monitoring of these patients is required during the patient's entire life. The limited number of food and drug administration approved biologic response modifier agents for the treatment of Juvenile idiopathic arthritis associated uveitis justify more randomized clinical trials with new medications in this field.

B Cells on the Stage of Inflammation in Juvenile Idiopathic Arthritis: Leading or Supporting Actors in Disease Pathogenesis?

Juvenile idiopathic arthritis (JIA) is a term that collectively refers to a group of chronic childhood arthritides, which together constitute the most common rheumatic condition in children. The International League of Associations for Rheumatology (ILAR) criteria define seven categories of JIA: oligoarticular, polyarticular rheumatoid factor (RF) negative (RF-), polyarticular RF positive (RF+), systemic, enthesitis-related arthritis, psoriatic arthritis, and undifferentiated arthritis. The ILAR classification includes persistent and extended oligoarthritis as subcategories of oligoarticular JIA, but not as distinct categories. JIA is characterized by a chronic inflammatory process affecting the synovia that begins before the age of 16 and persists at least 6 weeks. If not treated, JIA can cause significant disability and loss of quality of life. Treatment of JIA is adjusted according to the severity of the disease as combinations of non-steroidal anti-inflammatory drugs (NSAIDs), synthetic and/ or biological disease modifying anti-rheumatic drugs (DMARDs). Although the disease etiology is unknown, disturbances in innate and adaptive immune responses have been implicated in JIA development. B cells may have important roles in JIA pathogenesis through autoantibody production, antigen presentation, cytokine release and/ or T cell activation. The study of B cells has not been extensively explored in JIA, but evidence from the literature suggests that B cells might have indeed a relevant role in JIA pathophysiology. The detection of autoantibodies such as antinuclear antibodies (ANA), RF and anti-citrullinated protein antibodies (ACPA) in JIA patients supports a breakdown in B cell tolerance. Furthermore, alterations in B cell subpopulations have been documented in peripheral blood and synovial fluid from JIA patients. In fact, altered B cell homeostasis, B cell differentiation and B cell hyperactivity have been described in JIA. Of note, B cell depletion therapy with rituximab has been shown to be an effective and well-tolerated treatment in children with JIA, which further supports B cell intervention in disease development.

M-ficolin: a valuable biomarker to identify leukaemia from juvenile idiopathic arthritis

OBJECTIVE

Distinction on clinical grounds between acute lymphoblastic leukaemia presenting with arthropathy (ALLarthropathy) and juvenile idiopathic arthritis (JIA) is difficult, as the clinical and paraclinical signs of leukaemia may be vague. The primary aim was to examine the use of lectin complement pathway proteins as markers to differentiate ALLarthropathy from JIA. The secondary aims were to compare the protein levels at baseline and follow-up in a paired number of children with ALL and to examine the correlation with haematology counts, erythrocyte sedimentation reaction (ESR), C-reactive protein (CRP), blasts, relapse and death.

STUDY DESIGN

In this observational study, we measured M-ficolin, CL-K1 and MASP-3 in serum from children with ALL (n=151) and JIA (n=238) by time-resolved immunofluorometric assays. Logistic regression was used for predictions of ALL risk, considering the markers as the respective exposures. We performed internal validation using repeated '10-fold cross-validation' with 100 repetitions computing the area under the curve (AUC) as well as positive and negative predictive values in order to evaluate the predictive performance.

RESULTS

The level of M-ficolin was higher in JIA than ALLtotal and the ALLarthropathy subgroup. The M-ficolin level normalised after remission of ALL. M-ficolin could differentiate ALL from JIA with an AUC of 94% and positive predictive value (PPV) of 95%, exceeding CRP and haemoglobin. In a dichotomised predictive model with optimal cut-offs for M-ficolin, platelets and haemoglobin, AUC was 99% and PPV 98% in detecting ALL from JIA.

CONCLUSION

M-ficolin is a valuable marker to differentiate the child with ALL from JIA.

Clinical remission and subsequent relapse in patients with juvenile idiopathic arthritis: predictive factors according to therapeutic approach

BACKGROUND

Juvenile idiopathic arthritis constitutes a significant cause of disability and quality of life impairment in pediatric and adult patients. The aim of this study was to ascertain clinical remission (CR) and subsequent relapse in juvenile idiopathic arthritis (JIA) patients, according to therapeutic approach and JIA subtype. Evidence in literature regarding its predictors is scarce.

METHODS

We conducted an observational, ambispective study. Patients diagnosed of JIA, treated with synthetic and/or biologic disease modifying antirheumatic drugs (DMARD) were included and followed-up to December 31st, 2015. Primary outcome was clinical remission defined by Wallace criteria, both on and off medication. In order to ascertain CR according to therapeutic approach, DMARD treatments were divided in four groups: 1) synthetic DMARD (sDMARD) alone, 2) sDMARD combined with another sDMARD, 3) sDMARD combined with biologic DMARD (bDMARD), and 4) bDMARD alone.

RESULTS

A total of 206 patients who received DMARD treatment were included. At the time the follow-up was completed, 70% of the patients in the cohort had attained CR at least once (144 out of 206), and 29% were in clinical remission off medication (59 out of 206). According to treatment group, CR was more frequently observed in patients treated with synthetic DMARD alone (53%). Within this group, CR was associated with female sex, oligoarticular persistent subtypes, ANA positivity, Methotrexate treatment and absence of HLA B27, comorbidities and DMARD toxicity. 124 DMARD treatments (62%) were withdrawn, 64% of which relapsed. Lower relapse rates were observed in those patients with persistent oligoarticular JIA (93%) when DMARD dose was tapered before withdrawal (77%).

CONCLUSIONS

More than two thirds of JIA patients attained CR along the 9 years of follow-up, and nearly one third achieved CR off medication. Females with early JIA onset, lower active joint count and ANA positivity were the ones achieving and sustaining remission more frequently, especially when receiving synthetic DMARD alone and in the absence of HLA B27, comorbidities or previous DMARD toxicity.

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.

Identifying acute lymphoblastic leukemia mimicking juvenile idiopathic arthritis in children

Objective

Acute lymphoblastic leukemia (ALL) may present with arthritis implying the risk of being misdiagnosed as juvenile idiopathic arthritis (JIA). The aim of this study was to identify predictors for ALL based on clinical and laboratory information.

Methods

This cross-sectional, retrospective study compared clinical presentation and laboratory results of 26 children with ALL and arthritis versus 485 children with JIA (433 non-systemic, 52 systemic JIA). Using a Bayesian score approach the findings were evaluated by calculating odds ratios (OR) and lnOR as a measure of diagnostic weight.

Results

Distinction on clinical grounds was difficult, as even a high number of joints involved did not exclude ALL. One or more hematologic cell counts were low (Hb <10 g/dL, platelet count <100 x 10⁹/L, neutrophil count < 1.0 x 10⁹/L) in 92% with ALL, 25% with systemic JIA and 10% with non-systemic JIA. Neutropenia and thrombocytopenia had the highest ORs of 128 (95% CI 43–387) and 129 (95% CI 26–638), each giving a diagnostic weight of 4. The estimated risks of ALL were 0.2% with normal cell counts and 9%, 67% and 100% when one, two or three cell lines were affected.

Conclusion

A simple count of cell lines with low counts can serve as a basic diagnostic strategy. Children with tri- or bilinear involvement should be referred to a bone marrow, and those with unilinear involvement a thorough screen for further evidence of ALL (organomegaly, ESR, LDH, uric acid, and blood smear).

Immune checkpoint inhibitor-induced inflammatory arthritis as a model of autoimmune arthritis

The development of inflammatory arthritis in patients receiving immune checkpoint inhibitor therapy is increasingly recognized due to the growing use of these drugs for the treatment of cancer. This represents an important opportunity not only to define the mechanisms responsible for the development of this immune-related adverse event and to ultimately predict or prevent its development, but also to provide a unique window into early events in the development of inflammatory arthritis. Knowledge gained through the study of this patient population, for which the inciting event is known, could shed light into the pathogenesis of autoimmune arthritis. This review will highlight the clinical and immunologic features of these entities to define common elements for future study.

Autoantibodies in the Pathogenesis, Diagnosis, and Prognosis of Juvenile Idiopathic Arthritis

Autoantibody production occurs in juvenile idiopathic arthritis (JIA) and numerous other autoimmune diseases. In some conditions, the autoantibodies are clearly pathogenic, whereas in others the roles are less defined. Here we review various autoantibodies associated with JIA, with a particular focus on antinuclear antibodies and antibodies recognizing citrullinated self-antigens. We explore potential mechanisms that lead to the development of autoantibodies and the use of autoantibody testing in diagnosis and prognosis. Finally, we compare and contrast JIA-associated autoantibodies with those found in adults with rheumatoid arthritis (RA).

Incidence and predictors of Uveitis in juvenile idiopathic arthritis in a Nordic long-term cohort study

BACKGROUND

The incidence of uveitis associated with juvenile idiopathic arthritis (JIA) varies around the world. Our aim was to investigate the incidence and predictors of uveitis in a Nordic population-based cohort.

METHODS

Consecutive JIA cases from defined geographical areas in Denmark, Finland, Sweden and Norway with disease onset between January 1997 to June 2000 were followed for median 98 months in this prospective longitudinal cohort study. Potential clinical and immunological predictors of uveitis were identified with logistic regression analysis.

RESULTS

Uveitis occurred in 89 (20.5%) of the 435 children with regular ophtalmologic follow-up among the 500 included. Chronic asymptomatic uveitis developed in 80 and acute symptomatic uveitis in 9 children. Uveitis developed at a median interval of 0.8 (range - 4.7 to 9.4) years after onset of arthritis. Predictors of uveitis were age < 7 years at JIA onset (Odds ratio (OR) 2.1, 95% confidence interval (CI) 1.3 to 3.5), presence of antihistone antibodies (AHA) > 15 U/ml (OR 4.8 (1.8 to 13.4)) and antinuclear antibodies (ANA) (OR 2.4 (1.5 to 4.0)). Mean combined IgM/IgG AHA was significantly higher in the uveitis group (19.2 U/ml) than in the non-uveitis group (10.2 U/ml) (p = 0.002). Young age at JIA onset predicted uveitis in girls (p < 0.001), but not in boys (p = 0.390).

CONCLUSION

Early-onset arthritis and presence of AHA in girls, as well as presence of ANA in both genders, were significant predictors of chronic uveitis. The high incidence of uveitis in this long-term Nordic JIA cohort may have severe implications in a lifelong perspective.