Pathogenesis of systemic inflammatory diseases in childhood: "Lessons from clinical trials of anti-cytokine monoclonal antibodies for Kawasaki disease, systemic onset juvenile idiopathic arthritis, and cryopyrin-associated periodic fever syndrome"

Epidemiology conduction of paediatric rheumatic diseases based on the registry database of the Pediatric Rheumatology Association of Japan

OBJECTIVES

Although epidemiological surveys of paediatric rheumatic diseases in Japan have been conducted, they were single surveys with no continuity. This is the first report of the Pediatric Rheumatology Association of Japan registry database, which was established to continuously collect data for paediatric rheumatic diseases.

METHODS

Pediatric Rheumatology International Collaborate Unit Registry version 2 (PRICUREv2) is a registry database established by the Pediatric Rheumatology Association of Japan. The registry data were analysed for the age of onset, time to diagnosis, sex differences, seasonality, and other factors.

RESULTS

Our data showed the same trend regarding rates of paediatric rheumatic diseases reported in Japan and other countries. The age of onset was lower in juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis and higher in systemic lupus erythematosus and Sjögren's syndrome. The time to diagnosis was relatively short in JIA and systemic lupus erythematosus but longer in juvenile dermatomyositis and Sjögren's syndrome. Rheumatoid factor-positive polyarticular JIA showed a seasonality cluster with regard to onset.

CONCLUSION

PRICUREv2 aided the retrieval and evaluation of current epidemiological information on patients with paediatric rheumatic diseases. It is expected that the data collection will be continued and will be useful for expanding research in Japan.

18F-fluorodeoxyglucose-positron emission tomography/computed tomography for the diagnosis of polymyalgia-like illnesses: a retrospective study

Background

Various inflammatory conditions may present with musculoskeletal symptoms similar to those of polymyalgia rheumatica (PMR). We investigated findings on ¹⁸F-fluorodexoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) images that may differentiate PMR from polymyalgia-like illnesses.

Methods

We analyzed data from 25 patients with new-onset polymyalgia-like illnesses who fulfilled Bird's diagnostic criteria for PMR and had undergone FDG-PET/CT scan. To assess the uptake by major joints and synovial bursae, particularly at PMR-specific sites (shoulder, sternoclavicular, and hip joints, interspinous bursae, ischial tuberosities, and greater trochanters), we used visual scoring system to score FDG uptake: 0, no uptake (same as bone); 1, slight uptake; 2, moderate uptake (same as the liver); 3, greater uptake than the liver; and 4, uptake as strong as in the cerebellum.

Results

The final diagnoses were PMR in 17 patients and non-PMR in eight patients (three malignancies, two infections, one cholesterol crystal embolism, one ANCA-associated vasculitis, and one undefined diagnosis). Although the serum MMP-3 levels were significantly higher in patients with PMR, C-reactive protein and erythrocyte sedimentation rate mean values did not differ between the two groups. In PMR-specific sites, FDG accumulations were observed in all cases of PMR, with a high PET-positive score of 2.00 (range, 0-3), but it was low in non-PMR cases, with a PET-positive score of 1.00 (range, 0-3).

Conclusions

The FDG accumulation patterns in polymyalgia-like illness differ from those in PMR, despite the similar clinical presentations of both conditions. An FDG-PET/CT scan is useful for differentiating PMR from other polymyalgia-like illnesses.

[Association between autophagy and systemic juvenile idiopathic arthritis and related mechanism: a preliminary study]

OBJECTIVE

To study the role of autophagy in the development of systemic juvenile idiopathic arthritis (sJIA) by analyzing the expression of microtubule-associated protein 1 light chain 3-II (LC3-II), myeloid differentiation factor 88 (MyD88), and suppressor of T-cell receptor signaling 1 (STS-1) in peripheral blood lymphocytes of children with sJIA.

METHODS

A total of 26 children with sJIA were enrolled as the sJIA group, and 26 healthy children were enrolled as the control group. Western blot was used to measure the protein expression of LC3-II, STS-1, and MyD88 in peripheral blood lymphocytes. Immunofluorescence assay was used to measure the expression of LC3-II in the cytoplasm of lymphocytes. Pearson correlation analysis was used to assess the correlation between indices.

RESULTS

Compared with the control group, the sJIA group had significant increases in the expression of LC3-II, STS-1, and MyD88 (P<0.05). In the sJIA group, the expression of LC3-II was positively correlated with that of MyD88 (r=0.478, P<0.05), and the expression of STS-1 was also positively correlated with that of MyD88 (r=0.817, P<0.05).

CONCLUSIONS

There is high expression of LC3-II in peripheral blood lymphocytes of children with sJIA, suggesting that the development of sJIA may be associated with excessive expression of autophagy. STS-1 may induce autophagy by activating some signaling pathways, and MyD88 may participate in autophagy through the Toll-like receptor signaling pathway.

Tofacitinib Treatment of Refractory Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis (sJIA) is an aggressive form of childhood arthritis accompanied by persistent systemic inflammation. Patients with sJIA often exhibit poor response to conventional disease-modifying antirheumatic drugs, and chronic glucocorticoid use is associated with significant adverse effects. Although biologics used to target interleukin 1 and interleukin 6 are efficacious, the long-term commitment to frequent injections or infusions remains a challenge in young children. Janus-activated kinase (JAK) inhibitors block the signaling of numerous proinflammatory cytokines and are now used clinically for the treatment of rheumatoid arthritis in adults. Whether this new class of medication is effective for sJIA has not been reported. Here, we describe the case of a 13-year-old girl with recalcitrant sJIA characterized by polyarticular arthritis, fever, lymphadenopathy, and serological features of inflammation. She showed minimal response to nonsteroidal antiinflammatory drugs, glucocorticoids, conventional disease-modifying antirheumatic drugs, and etanercept. She also developed osteoporosis and vertebral compression fracture as the result of chronic glucocorticoid therapy. Oral therapy with the JAK inhibitor tofacitinib was initiated, and the patient experienced steady improvement of both arthritis and systemic features. Complete remission was achieved after 3 months, and no evidence of disease activity or adverse effects was seen through 6 months of follow-up. Our experience reveals the effectiveness of JAK inhibition in a case of refractory sJIA. Tofacitinib is an intriguing oral alternative to the available biologics for children with sJIA, and its efficacy and safety should be further assessed by clinical trial.

Allogeneic hematopoietic stem cell transplantation for severe, refractory juvenile idiopathic arthritis

Patients with juvenile idiopathic arthritis (JIA) can experience a severe disease course, with progressive destructive polyarthritis refractory to conventional therapy with disease-modifying antirheumatic drugs including biologics, as well as life-threatening complications including macrophage activation syndrome (MAS). Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative immunomodulatory strategy for patients with such refractory disease. We treated 16 patients in 5 transplant centers between 2007 and 2016: 11 children with systemic JIA and 5 with rheumatoid factor-negative polyarticular JIA; all were either refractory to standard therapy, had developed secondary hemophagocytic lymphohistiocytosis/MAS poorly responsive to treatment, or had failed autologous HSCT. All children received reduced toxicity fludarabine-based conditioning regimens and serotherapy with alemtuzumab. Fourteen of 16 patients are alive with a median follow-up of 29 months (range, 2.8-96 months). All patients had hematological recovery. Three patients had grade II-IV acute graft-versus-host disease. The incidence of viral infections after HSCT was high, likely due to the use of alemtuzumab in already heavily immunosuppressed patients. All patients had significant improvement of arthritis, resolution of MAS, and improved quality of life early following allo-HSCT; most importantly, 11 children achieved complete drug-free remission at the last follow-up. Allo-HSCT using alemtuzumab and reduced toxicity conditioning is a promising therapeutic option for patients with JIA refractory to conventional therapy and/or complicated by MAS. Long-term follow-up is required to ascertain whether disease control following HSCT continues indefinitely.

The First Case Series of Cryopyrin-Associated Periodic Syndrome in Korea

Cryopyrin-associated periodic syndrome (CAPS) is a hereditary autoinflammatory syndrome caused by mutations in NLRP3 (encoding cryopyrin), which presents with fever, fatigue and arthralgia. Thus far, however there have been no reports of CAPS in Korea. Herein, we report 3 cases of CAPS for the first time in Korea. The first case, a 28-year-old man with recurrent urticaria, arthralgia and fever induced by cold, all of which were observed in his father, showed elevated erythrocyte sedimentation rate and C-reactive protein. He exhibited a p.Gly303Asp variant of the NLPR3 gene. The second case, a 2-year-old girl who had recurrent urticaria, arthritis and oral and genital ulcers, was positive for HLA B51 and a p.Glu569Lys mutation in exon 3 of the NLRP3 gene. Administration of anakinra greatly improved her symptoms. The third case, a 4-year-old boy who presented with recurrent urticaria, arthralgia, and fever, exhibited a p.Val72Met mutation in exon 1 of the NLRP3 gene. Administration of tocilizumab improved all of his symptoms. This small case series suggests that clinicians consider CAPS and conduct genetic studies when arthralgia and fever are accompanied by urticaria in Korea.

Kawasaki disease: guidelines of Italian Society of Pediatrics, part II - treatment of resistant forms and cardiovascular complications, follow-up, lifestyle and prevention of cardiovascular risks

This second part of practical Guidelines related to Kawasaki disease (KD) has the goal of contributing to prompt diagnosis and most appropriate treatment of KD resistant forms and cardiovascular complications, including non-pharmacologic treatments, follow-up, lifestyle and prevention of cardiovascular risks in the long-term through a set of 17 recommendations.Guidelines, however, should not be considered a norm that limits the treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient's condition, and disease severity or individual complications.