The interplay between serine proteases and caspase-1 regulates the autophagy-mediated secretion of Interleukin-1 beta in human neutrophils

Neutrophils play major roles against bacteria and fungi infections not only due to their microbicide properties but also because they release mediators like Interleukin-1 beta (IL-1β) that contribute to orchestrate the inflammatory response. This cytokine is a leaderless protein synthesized in the cytoplasm as a precursor (pro-IL-1β) that is proteolytically processed to its active isoform and released from human neutrophils by secretory autophagy. In most myeloid cells, pro-IL-1β is processed by caspase-1 upon inflammasome activation. Here we employed neutrophils from both healthy donors and patients with a gain-of-function (GOF) NLRP3-mutation to dissect IL-1β processing in these cells. We found that although caspase-1 is required for IL-1β secretion, it undergoes rapid inactivation, and instead, neutrophil serine proteases play a key role in pro-IL-1β processing. Our findings bring to light distinctive features of the regulation of caspase-1 activity in human neutrophils and reveal new molecular mechanisms that control human neutrophil IL-1β secretion.

Development and initial validation of a composite disease activity score for systemic juvenile idiopathic arthritis

OBJECTIVE

To develop a composite disease activity score for systemic JIA (sJIA) and to provide preliminary evidence of its validity.

METHODS

The systemic Juvenile Arthritis Disease Activity Score (sJADAS) was constructed by adding to the four items of the original JADAS a fifth item that aimed to quantify the activity of systemic features. Validation analyses were conducted on patients with definite or probable/possible sJIA enrolled at first visit or at the time of a flare, who had active systemic manifestations, which should include fever. Patients were reassessed 2 weeks to 3 months after baseline. Three versions were examined, including ESR, CRP or no acute-phase reactant.

RESULTS

A total of 163 patients were included at 30 centres in 10 countries. The sJADAS was found to be feasible and to possess face and content validity, good construct validity, satisfactory internal consistency (Cronbach's alpha 0.64-0.65), fair ability to discriminate between patients with different disease activity states and between those whose parents were satisfied or not satisfied with illness outcome (P < 0.0001 for both), and strong responsiveness to change over time (standardized response mean 2.04-2.58). Overall, these properties were found to be better than those of the original JADAS and of DAS for RA and of Puchot score for adult-onset Still's disease.

CONCLUSION

The sJADAS showed good measurement properties and is therefore a valid instrument for the assessment of disease activity in children with sJIA. The performance of the new tool should be further examined in other patient cohorts that are evaluated prospectively.

Biologic agents in juvenile spondyloarthropathies

The juvenile spondyloarthropathies (JSpA) are a group of related rheumatic diseases characterized by involvement of peripheral large joints, axial joints, and entheses (enthesitis) that begin in the early years of life (prior to 16(th) birthday).The nomenclature and concept of spondyloarthropathies has changed during the last few decades. Although there is not any specific classification of JSpA, diseases under the spondyloarthropathy nomenclature umbrella in the younger patients include: the seronegative enthesitis and arthropathy (SEA) syndrome, juvenile ankylosing spondylitis, reactive arthritis, and inflammatory bowel disease-associated arthritis. Moreover, the ILAR criteria for Juvenile Idiopathic Arthritis includes two categories closely related to spondyloarthritis: Enthesitis-related arthritis and psoriatic arthritis.We review the pathophysiology and the use of biological agents in JSpA. JSpA are idiopathic inflammatory diseases driven by an altered balance in the proinflammatory cytokines. There is ample evidence on the role of tumor necrosis factor (TNF) and interleukin-17 in the physiopathology of these entities. Several non-biologic and biologic agents have been used with conflicting results in the treatment of these complex diseases. The efficacy and safety of anti-TNF agents, such as etanercept, infliximab and adalimumab, have been analysed in controlled and uncontrolled trials, usually showing satisfactory outcomes. Other biologic agents, such as abatacept, tocilizumab and rituximab, have been insufficiently studied and their role in the therapy of SpA is uncertain. Interleukin-17-blocking agents are promising alternatives for the treatment of JSpA patients in the near future. Recommendations for the treatment of patients with JSpA have recently been proposed and are discussed in the present review.

Use of infliximab in patients with systemic juvenile idiopathic arthritis refractory to etanercept

OBJECTIVE

To analyse the effectiveness and safety of Infliximab in a group of patients with systemic juvenile idiopathic arthritis (SJIA) who had failed treatment with etanercept in a single paediatric rheumatology clinic.

METHODS

Patients with SJIA with active polyarthritis refractory to methotrexate (MTX) [> or = 20 mg/m2/week] for at least 3 months and to etanercept (up to 1 mg/kg twice weekly) for at least 6 months were included. All children received infliximab 3-10 mg per kg of body weight intravenously concomitantly with MTX 7.5-10 mg/week for 19 (2-113) weeks. Evaluation included ACR paediatric 30 criteria and presence of signs of systemic activity (fever, rash).

RESULTS

Six patients were included. Three patients met ACR paediatric 30 criteria at 2 weeks (2 patients) and 10 weeks after initiation of infliximab. Improvement lasted for 4, 12, and 84 weeks respectively. The presence of fever/rash was not modified by the treatment. Infliximab was discontinued due to moderate side effects in 4 patients. No serious side effects were observed.

CONCLUSIONS

Most patients with SJIA who fail to respond to etanercept may not reach sustained improvement when switched to infliximab. The only patient in our group who improved sustainedly with infliximab did not show any systemic features at the beginning of therapy. Further controlled studies are needed in order to assess efficacy of infliximab in children with refractory SJIA.

Etanercept in systemic juvenile idiopathic arthritis

OBJECTIVE

To evaluate the effectiveness of etanercept in patients with systemic juvenile idiopathic arthritis (SJIA) refractory to methotrexate (MTX) therapy in a pediatric rheumatology practice.

METHODS

Fifteen patients with SJIA with active polyarthritis refractory to higher dose MTX (> or = 20 mg/m2/week) for at least 3 months were included. Patients received etanercept 0.4 mg/Kg twice weekly concomitantly with MTX. Observed period of treatment ranged from 5 to 12 months (median 9 months).

RESULTS

Improvement of ESR, swollen and limited joint counts, functional capacity, and general wellbeing was achieved by 14/15 patients. The most significant impact on these variables was observed 3 to 5 months after treatment onset. Mean time to improvement was 2 months. In the 4 patients who presented fever and rash, these signs disappeared after the beginning of etanercept treatment and reappeared during flares. Three patients showed sustained clinical and biochemical remission on low dose MTX (< or = 5 mg/m2/week). Thirteen relapses were observed in 9 (60%) patients at a mean of 7.6 months after therapy was begun. Etanercept was discontinued due to lack of efficacy in 7 patients, only after higher dose (1 mg/kg/dose) was used. MTX and corticosteroid doses were decreased during the observation period. No serious side effects were observed.

CONCLUSIONS

Etanercept, in combination with MTX, demonstrated benefit soon after initiation of treatment in patients with refractory SJIA, but flares and progressive loss of effectiveness were observed with continued treatment in most patients. Sharp decreases in the dose of MTX and corticosteroids may have contributed to subsequent occurrence of flares. Changes in MTX and corticosteroids doses should probably need to be made gradually, and it is possible that patients on SJIA should continue on therapeutic doses of MTX while being on etanercept in order to maintain therapeutic benefit.

Chronic infantile neurological cutaneous and articular syndrome: two new cases with rare manifestations

CINCA/IOMID is a systemic inflammatory disorder of unknown aetiology that resembles congenital infection and systemic juvenile chronic arthritis (JCA). This disorder is characterized by neonatal onset, persistent rash, ocular inflammatory lesions, and progressive articular and neurological involvement. We report two new patients with this syndrome. Both children presented periodic bouts of cutaneous rash, fever, organomegaly, articular involvement with typical radiological features, and developmental delay. One of the patients presented neonatal jaundice and elevation of liver enzymes; inflammatory infiltrates were observed in the liver biopsy. The other patient showed retinal vasculitis detected at age 18 mo on fundoscopy and fluorescent angiography. Therapy with azathioprine was associated with prolonged remission of this complication. In both cases, the disease was diagnosed after some delay.

CONCLUSION

Early hepatitis and retinal vasculitis are rare features of CINCA/IOMID that may help differentiate this syndrome from JRA. Azathioprine may have induced the remission of vasculitis in one case.

Cholestasis in juvenile dermatomyositis: report of three cases

This report describes 3 cases of juvenile dermatomyositis (juvenile DM) complicated by cholestasis. All 3 patients had typical features of juvenile DM, and all developed a cholestatic syndrome within the initial months of their disease. Liver biopsy revealed mixed (cytoplasmic and ductal) cholestasis with no abnormalities in the intrahepatic ducts in all 3 cases. Cholestasis improved or was completely reversible upon treatment with prednisone. In the 2 patients who could be followed up long term, no sequelae remained. The possible role of inflammation in the pathogenesis of cholestasis in juvenile DM is discussed.