Update on research and clinical translation on specific clinical areas: From bench to bedside: How insight in immune pathogenesis can lead to precision medicine of severe juvenile idiopathic arthritis

Biomarkers in Systemic Juvenile Idiopathic Arthritis, Macrophage Activation Syndrome and Their Importance in COVID Era

Systemic juvenile idiopathic arthritis (sJIA) and its complication, macrophage activation syndrome (sJIA-MAS), are rare but sometimes very serious or even critical diseases of childhood that can occasionally be characterized by nonspecific clinical signs and symptoms at onset-such as non-remitting high fever, headache, rash, or arthralgia-and are biologically accompanied by an increase in acute-phase reactants. For a correct positive diagnosis, it is necessary to rule out bacterial or viral infections, neoplasia, and other immune-mediated inflammatory diseases. Delays in diagnosis will result in late initiation of targeted therapy. A set of biomarkers is useful to distinguish sJIA or sJIA-MAS from similar clinical entities, especially when arthritis is absent. Biomarkers should be accessible to many patients, with convenient production and acquisition prices for pediatric medical laboratories, as well as being easy to determine, having high sensitivity and specificity, and correlating with pathophysiological disease pathways. The aim of this review was to identify the newest and most powerful biomarkers and their synergistic interaction for easy and accurate recognition of sJIA and sJIA-MAS, so as to immediately guide clinicians in correct diagnosis and in predicting disease outcomes, the response to treatment, and the risk of relapses. Biomarkers constitute an exciting field of research, especially due to the heterogeneous nature of cytokine storm syndromes (CSSs) in the COVID era. They must be selected with utmost care-a fact supported by the increasingly improved genetic and pathophysiological comprehension of sJIA, but also of CSS-so that new classification systems may soon be developed to define homogeneous groups of patients, although each with a distinct disease.

Pathogenesis and Treatment of Refractory Disease Courses in Systemic Juvenile Idiopathic Arthritis: Refractory Arthritis, Recurrent Macrophage Activation Syndrome and Chronic Lung Disease

Systemic juvenile idiopathic arthritis is a distinct and heterogeneous disease presently classified under the umbrella of juvenile idiopathic arthritis, with some patients following a monophasic remitting course, whereas others have persistent disease with chronic organ- and life-threatening complications. Although biologic therapies have revolutionized treatment, recent follow-up studies report significant numbers of children with persistently active disease on long term follow-up. This review focuses on refractory disease courses, specifically refractory arthritis, systemic juvenile idiopathic arthritis with recurrent, or longstanding signs of macrophage activation syndrome, and systemic juvenile idiopathic arthritis associated with suspected, probable, or definite lung disease.

How autoinflammation may turn into autoimmune inflammation: Insights from monogenetic and complex IL-1 mediated auto-inflammatory diseases

IL-1 mediated auto-inflammatory diseases are characterised by episodes of unexplained fever, generalized and localized inflammation. The characteristic symptoms predominantly result from exaggerated activation of innate immune pathways. However, in some patients with typical IL-1 mediated diseases, chronic disease manifestations develop in the absence of acute inflammation, suggesting the involvement of adaptive immune pathways. We discuss clinical observations as well as novel insights in how chronic activation of innate immune pathways can lead to auto-immune disease features in patients with auto-inflammatory diseases and how we need to better understand these sequelae in order to improve treatment strategies.

Anakinra in children and adults with Still's disease

Systemic juvenile idiopathic arthritis and adult-onset Still’s disease are rare autoinflammatory disorders with common features, supporting the recognition of these being one disease—Still’s disease—with different ages of onset. Anakinra was recently approved by the European Medicines Agency for Still’s disease. In this review we discuss the reasoning for considering Still’s disease as one disease and present anakinra efficacy and safety based on the available literature. The analysis of 27 studies showed that response to anakinra in Still’s disease was remarkable, with clinically inactive disease or the equivalent reported for 23–100% of patients. Glucocorticoid reduction and/or stoppage was reported universally across the studies. In studies on paediatric patients where anakinra was used early or as first-line treatment, clinically inactive disease and successful anakinra tapering/stopping occurred in >50% of patients. Overall, current data support targeted therapy with anakinra in Still’s disease since it improves clinical outcome, especially if initiated early in the disease course.

Juvenile Idiopathic Arthritis: Diagnosis and Treatment

Juvenile idiopathic arthritis is a broad term that describes a clinically heterogeneous group of arthritides of unknown cause, which begin before 16 years of age. This term encompasses several disease categories, each of which has distinct presentation, clinical manifestations, and, presumably, genetic background and etiopathogenesis. Although none of the available drugs has curative potential, prognosis has greatly improved as a result of substantial progresses in disease management. The most important new development has been the introduction of the biologic medications, which constitute a valuable treatment option for patients who are resistant to conventional antirheumatic agents. Further insights into the disease pathogenesis and treatment will be provided by the continuous advances in understanding of the mechanisms related to the immune response and inflammatory process, and by the development of new drugs that are capable of selectively inhibiting single molecules or pathways.

Efficacy and safety of biological agents for systemic juvenile idiopathic arthritis: a systematic review and meta-analysis of randomized trials

OBJECTIVE

To define the optimal biologic agent for systemic JIA (sJIA) based on safety and efficacy data from a randomized controlled trial (RCT).

METHODS

Through a systematic literature search, sJIA RCTs evaluating biologic agents were identified. The primary efficacy outcome was defined as a 30% improvement according to the modified American College of Rheumatology Paediatric 30 response criteria (JIA ACR30). The primary safety outcome was defined as serious adverse events (SAEs). Outcomes were analysed by pairwise and network meta-analyses. The quality of evidence between biologic agents was assessed by applying the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology.

RESULTS

From the 493 citations originally identified, 5 RCTs were eligible for inclusion-one each for anakinra, canakinumab and tocilizumab and two for rilonacept: all vs placebo. While all were effective, the network meta-analysis indicated with low-quality evidence (due to indirect comparison and inconsistency) that rilonacept-treated patients were less likely to respond than those treated with canakinumab [odds ratio (OR) 0.10 (95% CI 0.02, 0.38), P = 0.001] or tocilizumab [OR 0.12 (95% CI 0.03, 0.44), P = 0.001]. Risks of SAEs were similar among the biologic agents (supported by very low-quality evidence) and not different from placebo.

CONCLUSION

Despite heterogeneous eligibility criteria and study designs across the five studies and different modified JIA ACR30 criteria, this meta-analysis of short-term RCTs presents empirical evidence that canakinumab and tocilizumab are more effective than rilonacept. Biologic agents in sJIA seem safe and comparable with respect to SAE risk in the short term.

Optimizing treatment in paediatric rheumatology--lessons from oncology

Treatment of children with cancer, in particular with acute lymphoblastic leukaemia (ALL), has been highly successful in the past two decades owing to the implementation of treatment optimization studies. Study centres appointed by scientific societies design treatment optimization study protocols (TOSPs) that address an investigator-initiated research question and detail treatment procedures according to these aims. Nearly all children with malignant diseases are treated within TOSPs, whereas children with juvenile idiopathic arthritis (JIA) and other common paediatric rheumatic diseases are mostly treated outside TOSPs and clinical trials. Despite the differences in natural course and prognosis between malignant and inflammatory diseases, aiming for the recruitment of all children with defined rheumatic diseases into TOSPs or similar protocols would enable the longitudinal collection of crucial clinical data and improve evidence-based approaches. Successful research networks already exist in paediatric rheumatology that could facilitate the implementation of this approach. Paediatric rheumatic diseases have a considerable impact on patients and their families; thus, I propose that research networks in paediatric rheumatology should recruit most--if not all--children with rheumatic diseases into study protocols with standardized treatment and outcome measures.

Complications of systemic juvenile idiopathic arthritis: risk factors and management recommendations

Systemic juvenile idiopathic arthritis (SJIA) is an inflammatory condition characterized by fever, lymphadenopathy, arthritis, rash and serositis. Systemic inflammation has been associated with dysregulation of the innate immune system, suggesting that SJIA is an autoinflammatory disorder. IL-1 and IL-6 play a major role in the pathogenesis of SJIA, and treatment with IL-1 and IL-6 inhibitors has shown to be highly effective. However, complications of SJIA, including macrophage activation syndrome, limitations in functional outcome by arthritis and long-term damage from chronic inflammation, continue to be a major issue in SJIA patients' care. Translational research leading to a profound understanding of the cytokine crosstalk in SJIA and the identification of risk factors for SJIA complications will help to improve long-term outcome.

Advances in biomarkers for paediatric rheumatic diseases

The search for biomarkers in paediatric rheumatic diseases, particularly juvenile idiopathic arthritis (JIA), childhood lupus nephritis (LN), and juvenile idiopathic inflammatory myopathies (JIIMs) is attracting increased interest. In JIA, a number of biomarkers have shown potential for predicting clinical phenotype, disease activity and severity, clinical remission and relapse, response to treatment, and disease course over time. In systemic JIA, measurement of biomarkers that reflect the degree of activation and expansion of T cells and macrophages might be helpful for detecting subclinical macrophage activation syndrome. Urine biomarkers for childhood LN hold promise for facilitating early diagnosis and improving disease monitoring and assessment of response to therapy. Myositis-specific autoantibodies define distinct serological subgroups of JIIMs, albeit with similar clinical features, responses to therapy, and prognoses. Use of biomarkers may potentially help to avoid invasive procedures, such as renal biopsy in systemic lupus erythematosus and muscle biopsy in juvenile dermatomyositis. Incorporation of effective and reliable biomarkers into routine practice might facilitate adoption of a stratified approach to investigation and management, foster the implementation of research into the design of personalized and targeted therapies, and ultimately lead to more rational and effective clinical care.