Objective To formulate consensus treatment plans (CTPs) for induction therapy of newly-diagnosed proliferative lupus nephritis (LN) in juvenile systemic lupus erythematosus (jSLE). Methods A structured consensus formation process was employed by the members of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) after considering the existing medical evidence and current treatment approaches. Results After an initial Delphi survey (response rate 70%), a 2-day consensus conference, and two follow-up Delphi surveys (response rates 63–79%), consensus was achieved for a limited set of CTPs addressing the induction therapy of proliferative LN. These CTPs were developed for prototypic patients defined by eligibility characteristics, and included immunosuppressive therapy with either mycophenolic acid orally twice per day, or intravenous cyclophosphamide once per month at standardized doses for six months. Additionally, the CTPs describe three options for standardized use of glucocorticoids; including a primarily oral, a mixed oral/intravenous, and a primarily intravenous regimen. There was consensus on measures of effectiveness and safety of the CTPs. The CTPs were well accepted by the pediatric rheumatology providers treating children with LN, and up to 300 children per year in North America are expected to be candidates for the treatment with the CTPs. Conclusion CTPs for induction therapy of proliferative LN in jSLE based on the available scientific evidence and pediatric rheumatology group experience have been developed. Consistent use of the CTPs may improve the prognosis of proliferative LN, and support the conduct of comparative effectiveness studies aimed at optimizing therapeutic strategies for proliferative LN in jSLE.

ObjectiveTo investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA).MethodsIn a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data.ResultsLD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features.ConclusionsA rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.

Objective To investigate characteristics and risk factors of a novel parenchymal lung disease, increasingly detected in systemic juvenile idiopathic arthritis (sJIA). Methods In a multi-center retrospective study, 61 cases were investigated, using physician-reported clinical information and centralized analyses of radiologic, pathologic and genetic data. Results Lung disease (LD) was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the IL-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes +/- ground glass opacities. Predominant pathology (23/36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features, including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. 5-year survival was 42%. Whole-exome sequencing (20/61) did not identify a novel monogenic defect PAP-related or macrophage activation syndrome (MAS)-related mutations as likely primary cause. Trisomy 21 (T21) increased LD risk, as did young sJIA onset. Refractory sJIA was not required for LD development. Exposure to interleukin (IL)-1 and IL-6 inhibitors (46/61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but it was not associated with LD features. Conclusions A rare, life-threatening LD in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.