Anti-type II collagen antibodies, anti-CCP, IgA RF and IgM RF are associated with joint damage, assessed eight years after onset of juvenile idiopathic arthritis (JIA)

A lifelong journey: Long-term perspectives on Juvenile Idiopathic Arthritis

Juvenile Idiopathic Arthritis (JIA) represents a diverse group of chronic inflammatory conditions that begin in childhood or adolescence and continue into adulthood, with varying severity and outcomes. This review discusses the complexities of transitioning JIA patients emphasizing that inadequate transition from pediatric to adult care leads to loss of follow-up, treatment discontinuation, and increased disease activity. Furthermore, challenges in disease classification hinder continuity of care across lifespan. It is also pointed out that predicting long-term outcomes in JIA remains complex due to heterogeneity and evolving phenotypes. Factors such as disease category, joint involvement, and treatment influence disease activity, functional disability, and quality of life. Despite advancements in treatment strategies, a substantial proportion of patients experience long-term disability and joint damage. Finally, it is underscored that optimising long-term outcomes in adults with JIA requires a multifaceted approach encompassing structured transition processes, personalised treatment strategies, and comprehensive management of comorbidities. Further research is needed to refine predictive models, enhance disease monitoring tools, and understand the complex interplay between disease activity, treatment response, and long-term outcomes.

Rheumatoid factor value for determining the first biologic agent to use for non-systemic juvenile idiopathic arthritis

OBJECTIVES

Currently, no indicators on which biologic disease-modifying anti-rheumatic drugs (bDMARDs) should be used first for juvenile idiopathic arthritis (JIA) have been established. Thus, this study aimed to determine the useful biomarkers in JIA to enable the best selection of the first bDMARDs without primary failure.

METHODS

This retrospective study used data of patients examined for JIA between 2015 and 2021 at Kagoshima University Hospital in Japan.

RESULTS

Altogether, 67 cases of non-systemic JIA were analyzed, excluding cases that had been treated for <6 months. Of the 67 cases, 52 were treated with bDMARDs and all rheumatoid factor (RF)+ types (32 cases) were treated with bDMARDs. Eleven cases (31.4&) (all were RF+ types and used anti-tumor necrosis factor (TNF)α agents) switched to other bDMARDs because of primary failure, and nine cases had secondary failure (6;anti-TNF, 3;anti-Interleukin-6). A significant difference in pre-treatment RF values (177.9 vs 25.7 IU/ml, p = 0.002) and presence (Odds Ratio 1.952,p = 0.004) were observed between the primary failure group and effective group.

CONCLUSIONS

RF+ JIA required bDMARDs with high probability. JIA with high titre of RF tends to be refractory to anti-TNFα agents. Tocilizumab or abatacept could be a first-choice bDMARD in such cases.

Latent classes of early response trajectories to biologics initiation in juvenile idiopathic arthritis: an analysis of four trials

AIMS

1) To delineate latent classes of treatment response to biologics in juvenile idiopathic arthritis (JIA) patients in the first 16 weeks after initiation. 2) To identify predictors of early disease response.

METHODS

The study population was drawn from four biologics trials in polyarticular course JIA: Etanercept 2000, Abatacept 2008, TRial of Early Aggressive Therapy (TREAT) 2012 and Tocilizumab 2014. The outcome was active joint counts (AJC). Semiparametric latent class trajectory analysis was applied to identify latent classes of response to treatment; AJC was transformed for this modelling. We tested baseline disease and treatment characteristics for their abilities to predict class membership of response.

RESULTS

There were 480 participants, 74% females. At baseline, 26% were rheumatoid factor positive. 67% were on methotrexate at enrollment. Three latent class solution provided the best fit. Baseline AJC was the sole best predictor of class membership. Participants classified by their highest membership probabilities into high baseline AJC (> 30) and slow response (26.5%), low baseline AJC (< 10), early and sustained response (29.7%), and moderate baseline AJC progressive response (43.8%). Participants were classified into the latent classes with a mean class membership posterior probability of 0.97. Those on methotrexate at baseline were less likely to belong to high baseline AJC class.

CONCLUSIONS

Three latent classes of responses were detectable in the first 16 weeks of biologics therapy. Those with the highest baseline AJC demonstrated very slow response in this window and were less likely to be on concomitant methotrexate.

TRIALS REGISTRATION

TREAT 2012 (NCT NCT00443430 ) (Wallace et. al, Arthritis Rheum 64:2012-21, 2012), tocilizumab trial 2014 ( NCT00988221 ), abatacept trial 2008 ( NCT00095173 ). Etanercept 2000 from Amgen does not have a trial registration number.

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.

Juvenile idiopathic arthritis: from aetiopathogenesis to therapeutic approaches

Juvenile idiopathic arthritis (JIA) is the most common paediatric rheumatological disorder and is classified by subtype according to International League of Associations for Rheumatology criteria. Depending on the number of joints affected, presence of extra-articular manifestations, systemic symptoms, serology and genetic factors, JIA is divided into oligoarticular, polyarticular, systemic, psoriatic, enthesitis-related and undifferentiated arthritis. This review provides an overview of advances in understanding of JIA pathogenesis focusing on aetiology, histopathology, immunological changes associated with disease activity, and best treatment options. Greater understanding of JIA as a collective of complex inflammatory diseases is discussed within the context of therapeutic interventions, including traditional non-biologic and up-to-date biologic disease-modifying anti-rheumatic drugs. Whilst the advent of advanced therapeutics has improved clinical outcomes, a considerable number of patients remain unresponsive to treatment, emphasising the need for further understanding of disease progression and remission to support stratification of patients to treatment pathways.

Concerted Actions by PIICP, CTXII, and TNF-α in Patients with Juvenile Idiopathic Arthritis

Joint destruction in juvenile idiopathic arthritis (JIA), initiated in the early, preclinical stage of the disease, is diagnosed on the basis of clinical evaluation and radiographic imaging. The determination of circulating cartilage-matrix turnover markers can facilitate the diagnosis and application of better and earlier treatment strategies for JIA. We have shown that 96 JIA patients have elevated levels of procollagen II C-terminal propeptide (PIICP), reflecting the extent of joint cartilage biosynthesis, and C-telopeptide of type II collagen (CTXII), a biomarker of the resorption of this tissue. Patients who did not respond to treatment had particularly high levels of these markers. JIA treatment resulted in the normalization of these markers in remissive patients, but not in those with active JIA. We showed correlations between examined variables and inflammatory process indicators, i.e., C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and tumor necrosis factor-α (TNF-α). The TNF-α of patients responding to treatment correlated with PIICP, especially in the patients before treatment (r = 0.898, p < 0.001). Significant changes in serum PIICP during JIA therapy suggest its potential diagnostic utility in the monitoring of disease activity and the possibility of its use in assessing treatment towards remission. Understanding changes in type II collagen metabolism over the course of the discussed arthritis may allow the implementation of both new diagnostic tools and new therapeutic strategies in children with JIA.

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).

Clinical and diagnostic significance of serum immunoglobulin A rheumatoid factor in primary Sjogren's syndrome

OBJECTIVES

The aim of this study was to investigate the diagnostic accuracy of rheumatoid factor (RF) isotype for the detection of primary Sjogren's syndrome (pSS) and evaluate the clinical and serological associations of immunoglobulin (Ig) A RF in patients with pSS.

MATERIALS AND METHODS

RF levels were measured in 77 and 37 patients with pSS and idiopathic sicca symptoms, respectively, using ELISA and analysed with respect to clinical and laboratory disease characteristics. Receiver operating characteristic curves were used to determine and compare the diagnostic accuracy of IgA RF with other diagnostic tests.

RESULTS

Serum levels of IgA RF were significantly higher in patients with pSS than in those with idiopathic sicca symptoms. IgA RF showed sensitivity, specificity, positive, and negative predictive values of 83.1, 78.4, 88.9, and 69.0%, respectively, for pSS diagnosis. IgA RF was associated with xerostomia, severe sialoscintigraphic grade, low unstimulated salivary flow rate (USFR), antinuclear antibody, high IgG and IgM/G RF levels, and low C3 levels in patients with pSS. IgA RF titres had positive correlations with sialoscintigraphic grade and IgG and IgG/M RF levels and had negative correlations with USFR and C3 levels.

CONCLUSION

Our findings confirmed the potential of IgA RF to distinguish pSS from idiopathic sicca symptoms. The presence of IgA RF in patients with pSS was associated with significantly worse exocrine function and active serologic profile. No association between IgA RF and extra-glandular manifestations was noted.

CLINICAL RELEVANCE

IgA RF should be the predictive and diagnostic marker in patients with pSS.

How common is remission in juvenile idiopathic arthritis: A systematic review

Objectives

The ideal goal of treatment for juvenile idiopathic arthritis (JIA) is disease remission. However, many sets of remission criteria have been developed and no systematic review of remission in JIA exists.

The current systematic review investigated (1) how remission has been defined across JIA clinical cohorts and (2) the frequency of remission overall and within disease categories.

Methods

Studies using prospective inception cohorts published after 1972 were selected if they estimated remission in cohorts of ≥50 patients. Articles focusing on specific medical interventions, not defining remission clearly or not reporting disease duration at remission assessment were excluded. Studies were selected from Medline, Embase, PubMed and bibliographies of selected articles. Risks of selection, missing outcome data and outcome reporting biases were assessed.

Results

Within 17 studies reviewed, 88% had majority female participants and patient disease duration ranged from 0.5 to 17 years. Thirteen sets of criteria for clinically inactive disease and remission were identified. Uptake of Wallace’s preliminary criteria was good in studies recruiting or following patients after their publication (78%).

Remission frequencies increased with longer disease duration from 7% within 1.5 years to 47% by 10 years following diagnosis. Patients with persistent oligoarticular and rheumatoid-factor positive polyarticular JIA were most and least likely to achieve remission, respectively.

Conclusions

Achievement of remission increased with longer disease duration, but many patients remain in active disease, even in contemporary cohorts. Multiple sets of outcome criteria limited comparability between studies.

IL-1β and IL-6 Are Highly Expressed in RF+IgE+ Systemic Lupus Erythematous Subtype

Background. Systemic lupus erythematosus (SLE) is an autoimmune disease with great heterogeneity in pathogenesis and clinical symptoms. Rheumatoid factor (RF) is one key indicator for rheumatoid arthritis (RA) while immunoglobulin E (IgE) is associated with type I hypersensitivity. To better categorize SLE subtypes, we determined the dominant cytokines based on familial SLE patients. Methods. RF, IgE, and multiple cytokines (i.e., IL-1β, IL-6, IL-8, IL-10, IL-17, IFN-γ, IP-10, MCP-1, and MIP-1β) were measured in sera of familial SLE patients (n = 3), noninherited SLE patients (n = 108), and healthy controls (n = 80). Results. Three familial SLE patients and 5 noninherited SLE cases are with features of RF+IgE+. These RF+IgE+ SLE patients expressed significantly higher levels of IL-1β and IL-6 than the other SLE patients (P < 0.05). IL-6 correlated with both IgE and IL-1β levels in RF+IgE+ SLE patients (r² = 0.583, P = 0.027; r² = 0.847, P = 0.001), and IgE also correlated with IL-1β (r² = 0.567, P = 0.031). Conclusion. Both IL-1β and IL-6 are highly expressed cytokines in RF+IgE+ SLE subtype which may be related to the pathogenesis of this special SLE subtype and provide accurate treatment strategy by neutralizing IL-1β and IL-6.

Juvenile porcine temporomandibular joint: Three different cartilaginous structures?

OBJECTIVE

The temporomandibular joint (TMJ) consists of three cartilaginous structures: the fossa, disc, and condyle. In juvenile idiopathic arthritis (JIA), inflammation of the TMJ leads to destruction of the condyle, but not of the fossa or the disc. Such a different effect of inflammation might be related to differences in matrix composition of the cartilaginous structures.

METHODS

The matrix composition of the three TMJ structures was analyzed in juvenile porcine samples and in an in vitro system of cells isolated from each anatomical structure embedded in 3% agarose gels.

RESULTS

The matrix of all three anatomical structures of the TMJ contained collagen type I and its gene expression was maintained after isolation. The condyle and the fossa stained positive for collagen type II and proteoglycans, but the condyle contained considerably more collagen type II and proteoglycans than the fossa. The disc contained neither collagen type II protein nor expression of its gene, and the disc did not stain positive for proteoglycans. Aggrecan gene expression was lower in the disc compared to condyle and fossa cell-isolates. In general, the cell-isolates in vitro closely mimicked the characteristic features found in the tissue.

CONCLUSION

The collagen type II content of the condyle clearly distinguished this cartilaginous structure from the disc and fossa. Since autoimmunity against collagen type II is associated with JIA, the relatively abundant presence of this type of collagen in the condyle might provide an explanation why primarily this cartilaginous structure of the TMJ is affected in JIA patients.

Review of biomarkers in systemic juvenile idiopathic arthritis: helpful tools or just playing tricks?

BACKGROUND

Diagnosing systemic juvenile idiopathic arthritis (SJIA) can be extremely challenging if typical arthritis is lacking. A variety of biomarkers have been described for the diagnosis and management of SJIA. However, very few markers have been well-validated. In addition, increasing numbers of biomarkers are identified by high throughput or multi-marker panels.

METHOD

We identified diagnostic or prognostic biomarkers by systematic literature review, evaluating each according to a predefined level of verification, validation or clinical utility. Diagnostic biomarkers were those identifying SJIA versus (1) non-SJIA conditions or healthy controls (HC) or (2) other non-systemic JIA subtypes. Prognostic biomarkers were those specifically tested for the prediction of (1) disease flare, (2) increased disease activity +/- discrimination of active versus inactive disease, or (3) macrophage activation syndrome (MAS).

RESULTS

Fifty-five studies fulfilled the inclusion criteria identifying 68 unique biomarkers, of which 50/68 (74 %) were investigated by only a single research group. Candidate marker verification and clinical utility was evaluated according to whether markers were readily and reliably measurable, investigated by independent study groups, discovered by more than one method (i.e. verified markers) and validated in independent cohorts. This evaluation revealed diagnostic biomarkers of high interest for further evaluation in the diagnostic approach to SJIA that included heme oxygenase-1, interleukin-6 (IL-6), IL-12, IL-18, osteoprotegerin, S100 calcium-binding protein A12 (S100A12) and S100A8/A9.

CONCLUSION

In summary, a number of biomarkers were identified, though most had limited evidence for their use. However, our findings combined with the identified studies could inform validation studies, whether in single or multi-marker assays, which are urgently needed.

Long-term outcome in juvenile-onset mixed connective tissue disease: a nationwide Norwegian study

OBJECTIVES

To describe the characteristics, outcome and predictive factors of juvenile mixed connective tissue disease (JMCTD) in a nationwide cohort of patients.

METHODS

We examined 55 patients with JMCTD after a mean disease duration of 16.2 years (SD 10.0). Patients were registered according to Kasukawa's criteria. Remission criteria were defined according to those for juvenile idiopathic arthritis, plus absence of cytopenia, myositis, progressive sclerodactyly, lung and oesophageal manifestations. Organ damage was assessed with the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index and the Juvenile Arthritis Damage Index (JADI). Medical records were reviewed for early predictors for outcome, which were assessed by multivariate logistic regression analyses.

RESULTS

Three patients developed systemic lupus erythematosus (SLE). Fifty-two patients had continuous JMCTD; the most common manifestations were: Raynaud (100%), arthritis (94%), puffy hands (77%) and pulmonary manifestations (58%). SLE-like, systemic sclerosis (SSc)-like and polymyositis (PM)-like findings were found in 98%, 77% and 48%, respectively. Over time, SLE-like and PM-like manifestations decreased, and SSc-like findings increased. At follow-up, 35 patients (67%) had active disease and 17 (33%) were in remission. In 34 patients (65%), SLICC or JADI≥1 assessments indicated organ damage. Active disease was associated with higher anti-ribonucleoprotein antibody titres at follow-up and positive rheumatoid factor (RF) at diagnosis and follow-up.

CONCLUSIONS

Most patients with JMCTD had active disease and organ damage after a mean follow-up of 16.2 years. Active disease was associated with higher anti-ribonucleoprotein antibody levels and positive RF. The presence of RF at diagnosis predicted persistent disease activity.

The role of parvovirus B19 in the pathogenesis of autoimmunity and autoimmune disease

Human parvovirus B19 is a single-stranded DNA virus which preferentially targets the erythroblasts in the bone marrow. B19 infection commonly causes erythema infectiosum, arthralgia, fetal death, transient aplastic crisis in patients with shortened red cell survival, and persistent infection in people who are immunocompromised. Less common clinical manifestations include atypical skin rashes, neurological syndromes, cardiac syndromes, and various cytopenias. B19 infection has also been associated with development of a variety of different autoimmune diseases, including rheumatological, neurological, neuromuscular, cardiovascular, haematological, nephrological and metabolic. Production of a variety of autoantibodies has been demonstrated to occur during B19 infection and these have been shown to be key to the pathogenesis of the particular disease process in a significant number of cases, for example, production of rheumatoid factor in cases of B19-associated rheumatoid arthritis and production of anti-glutamic acid decarboxylase (GAD) in patients with B19-associated type 1 diabetes mellitus. B19 infection has also been associated with the development of multiple autoimmune diseases in 12 individuals. Documented mechanisms in B19-associated autoimmunity include molecular mimicry (IgG antibody to B19 proteins has been shown to cross react with a variety of recognised human autoantigens, including collagen II, keratin, angiotensin II type 1 receptor, myelin basic protein, cardiolipin, and platelet membrane glycoprotein IIb/IIIa), B19-induced apoptosis with presentation of self-antigens to T lymphocytes, and the phospholipase activity of the B19 unique VP1 protein.

Evaluation of anti-cyclic citrullinated peptide antibodies may be beneficial in RF-negative juvenile idiopathic arthritis patients

Despite the high diagnostic and prognostic performance in adult rheumatoid arthritis, the role of antibodies to cyclic citrullinated peptide (anti-CCP) in juvenile idiopathic arthritis (JIA) is controversial. Occurrence of anti-CCP was mainly seen in rheumatoid factor (RF)-positive polyarthritis patients. In the present study, our aim was to investigate the prevalence and significance of anti-CCP for subjects with JIA in our population. We evaluated anti-CCP reactivity in the sera of 70 patients with various subtypes of JIA in a prospective cohort study. Anti-CCP titres were correlated with the evolution of joint involvement and the presence of joint damage. Nine JIA patients were seropositive for anti-CCP with respect to the cut-off value of the test. In our cohort, 34 patients had a polyarticular joint disease, most of them being RF-negative (30/34, 88 %). All four RF-positive polyarthritis patients had high anti-CCP concentrations and an aggressive erosive disease. In the RF-negative JIA patients, anti-CCP reactivity was in lower titres but significantly associated with polyarticular joint involvement (p = 0.016) and also with the presence of joint damage (p < 0.001). Presence of anti-CCP, at both low and high concentration, was significantly associated with a more severe articular disease in our JIA patients. Investigating anti-CCP should clearly be taken into consideration even among patients with JIA subtypes other than RF-positive polyarthritis.

Anti-type II collagen antibodies detection and avidity in patients with oligoarticular and polyarticular forms of juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) refers to a heterogeneous group of illnesses that have in common the occurrence of chronic joint inflammation in children younger than 16 years of age. The diagnosis is made only on clinical assessment. The identification of antibody markers could improve the early diagnosis, optimizing the clinical management of patients. Type II collagen is one potential autoantigen that has been implicated in the process of arthritis development. The aims of our study were to investigate the occurrence of anti-type II collagen antibodies and also to determine the avidity of the antibody-antigen binding. Ninety-six patients with oligoarticular or polyarticular JIA, 13 patients with ankylosing spondylitis (AS) and 61 healthy controls (HC) were tested for anti-type II collagen antibodies by ELISA and avidity ELISA. Sensitivity and specificity were determined by the receiver operating characteristic (ROC) curve analysis. Forty-two JIA patients (44%) were positive for antibodies against type II collagen. Its detection was significantly higher in JIA patients than in AS patients (p=0.006) and HCs (p<0.0001). Furthermore, anti-type II collagen antibody detection was significantly more frequent in patients with JIA of ≤6 months duration (p=0.0007). Antibodies displaying high avidity to type II collagen were associated with disease activity (p=0.004). This study demonstrates that antibodies against type II collagen are present in the serum of patients with oligoarticular and polyarticular JIA, being its presence more prevalent in patients with early disease. It also demonstrates that JIA patients with active disease present antibodies with high avidity against type II collagen.