Early Outcomes in Children With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

OBJECTIVE: To characterize the early disease course in childhood-onset antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and the 12-month outcomes in children with AAV. METHODS: Eligible subjects were children entered into the Pediatric Vasculitis Initiative study who were diagnosed before their eighteenth birthday as having granulomatosis with polyangiitis (Wegener's), microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (Churg-Strauss), or ANCA-positive pauci-immune glomerulonephritis. The primary outcome measure was achievement of disease remission (Pediatric Vasculitis Activity Score [PVAS] of 0) at 12 months with a corticosteroid dosage of <0.2 mg/kg/day. Secondary outcome measures included the rates of inactive disease (PVAS of 0, with any corticosteroid dosage) and rates of improvement at postinduction (4-6 months after diagnosis) and at 12 months, presence of damage at 12 months (measured by a modified Pediatric Vasculitis Damage Index [PVDI]; score 0 = no damage, score 1 = one damage item present), and relapse rates at 12 months. RESULTS: In total, 105 children with AAV were included in the study. The median age at diagnosis was 13.8 years (interquartile range 10.9-15.8 years). Among the study cohort, 42% of patients achieved remission at 12 months, 49% had inactive disease at postinduction (4-6 months), and 61% had inactive disease at 12 months. The majority of patients improved, even if they did not achieve inactive disease. An improvement in the PVAS score of at least 50% from time of diagnosis to postinduction was seen in 92% of patients. Minor relapses occurred in 12 (24%) of 51 patients after inactive disease had been achieved postinduction. The median PVDI damage score at 12 months was 1 (range 0-6), and 63% of patients had ≥1 PVDI damage item scored as present at 12 months. CONCLUSION: This is the largest study to date to assess disease outcomes in pediatric AAV. Although the study showed that a significant proportion of patients did not achieve remission, the majority of patients responded to treatment. Unfortunately, more than one-half of this patient cohort experienced damage to various organ systems early in their disease course.

Comparing Presenting Clinical Features in 48 Children With Microscopic Polyangiitis to 183 Children Who Have Granulomatosis With Polyangiitis (Wegener's): An ARChiVe Cohort Study.

OBJECTIVE: To uniquely classify children with microscopic polyangiitis (MPA), to describe their demographic characteristics, presenting clinical features, and initial treatments in comparison to patients with granulomatosis with polyangiitis (Wegener's) (GPA). METHODS: The European Medicines Agency (EMA) classification algorithm was applied by computation to categorical data from patients recruited to the ARChiVe (A Registry for Childhood Vasculitis: e-entry) cohort, with the data censored to November 2015. The EMA algorithm was used to uniquely distinguish children with MPA from children with GPA, whose diagnoses had been classified according to both adult- and pediatric-specific criteria. Descriptive statistics were used for comparisons. RESULTS: In total, 231 of 440 patients (64% female) fulfilled the classification criteria for either MPA (n = 48) or GPA (n = 183). The median time to diagnosis was 1.6 months in the MPA group and 2.1 months in the GPA group (ranging to 39 and 73 months, respectively). Patients with MPA were significantly younger than those with GPA (median age 11 years versus 14 years). Constitutional features were equally common between the groups. In patients with MPA compared to those with GPA, pulmonary manifestations were less frequent (44% versus 74%) and less severe (primarily, hemorrhage, requirement for supplemental oxygen, and pulmonary failure). Renal pathologic features were frequently found in both groups (75% of patients with MPA versus 83% of patients with GPA) but tended toward greater severity in those with MPA (primarily, nephrotic-range proteinuria, requirement for dialysis, and end-stage renal disease). Airway/eye involvement was absent among patients with MPA, because these GPA-defining features preclude a diagnosis of MPA within the EMA algorithm. Similar proportions of patients with MPA and those with GPA received combination therapy with corticosteroids plus cyclophosphamide (69% and 78%, respectively) or both drugs in combination with plasmapheresis (19% and 22%, respectively). Other treatments administered, ranging in decreasing frequency from 13% to 3%, were rituximab, methotrexate, azathioprine, and mycophenolate mofetil. CONCLUSION: Younger age at disease onset and, perhaps, both gastrointestinal manifestations and more severe kidney disease seem to characterize the clinical profile in children with MPA compared to those with GPA. Delay in diagnosis suggests that recognition of these systemic vasculitides is suboptimal. Compared with adults, initial treatment regimens in children were comparable, but the complete reversal of female-to-male disease prevalence ratios is a provocative finding.