<p><strong>OBJECTIVE: </strong>There are few reports on treatment of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in children. This study characterizes the use of cyclophosphamide, rituximab, and plasma exchange in children hospitalized with AAV in the United States.</p>

<p><strong>METHODS: </strong>We conducted a retrospective cohort study of children hospitalized with AAV from 2004-2014 utilizing an administrative and billing database from 47 tertiary care pediatric hospitals. All patients had an ICD-9-CM discharge code of 446.4 and ≥1 charge for glucocorticoids. Treatment receipt was determined using billing data. Mixed effects logistic regression evaluated factors associated with the likelihood of receipt of each of the three treatments.</p>

<p><strong>RESULTS: </strong>During the 11 year study period there were 1290 admissions for 393 children. Median age at index admission was 14.6 years and 61% were female. Sixteen percent and 17% of children required dialysis or mechanical ventilation, respectively. The median length of stay was 9 days. Fifty-seven percent, 21%, and 10% of children received cyclophosphamide, rituximab, or both, respectively. Twenty-two percent received plasma exchange. Mechanical ventilation was associated with receipt of cyclophosphamide and plasma exchange, but not rituximab. There was an increasing trend in use of rituximab over time during the study period (p&lt;0.05), and a decreasing trend in use of cyclophosphamide (p&lt;0.05). Treatment use varied significantly between hospitals, especially for plasma exchange.</p>

<p><strong>CONCLUSION: </strong>The treatment of children with severe AAV is shifting from cyclophosphamide to rituximab and their need for dialysis, mechanical ventilation, and prolonged hospitalization remains common. Use of plasma exchange is highly variable. This article is protected by copyright. All rights reserved.</p>

<p><strong>OBJECTIVES: </strong>To characterise the clinical course and outcomes of a cohort of children with granulomatosis with polyangiitis (GPA).</p>

<p><strong>METHODS: </strong>Retrospective cohort study of children diagnosed with GPA in a tertiary care facility from 2000-2014. All subjects met the American College of Rheumatology 1990 criteria for GPA or the 2008 European League against Rheumatism/Paediatric Rheumatology International Trials Organisation/Paediatric Rheumatology European Society criteria for GPA. Predictors of readmission were determined using univariate logistic regression. Kaplan-Meier analysis was used to demonstrate the relapse-free survival probability in follow-up.</p>

<p><strong>RESULTS: </strong>Twenty-eight children (median age 14.7 years) were diagnosed during the study period. At presentation 14 (50%), 5 (18%), and 4 (14%) children required intensive care unit care, ventilator support, and dialysis, respectively. One-third of the children in our cohort had gastrointestinal involvement, one-quarter of whom were previously diagnosed with inflammatory bowel disease. Two-thirds of children were readmitted. Renal failure and infections accounted for most readmissions. Twenty-three (85%) patients achieved remission, however, 11 subsequently flared (median time to flare 21.5 months). Haematuria at diagnosis was significantly associated with readmission (OR 6.25). At a median follow-up of 3.3 years (range 5 months to 6 years) 10 (37%) children had chronic kidney disease (&gt; stage 2) and none of the children died.</p>

<p><strong>CONCLUSIONS: </strong>Children with GPA frequently have severe disease presentations including significant renal, respiratory and gastrointestinal involvement. While most children with GPA achieve remission, nearly half have subsequent relapses.</p>