SESSION TITLE: Pulmonary Manifestations of Systemic Disease Student/Resident Case Report Posters I
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Microscopic polyangiitis (MPA) is a rare condition in children. Treatment can significantly reduce relapse and mortality, thus the importance of diagnosis is important.
CASE PRESENTATION: A previously healthy 13-year-old male was admitted for cough and hemoptysis. Initial exam was unremarkable. Tuberculosis work ups were negative. He had anemia, hematuria and proteinuria. CT chest showed mixed nodular and ground glass consolidation (FIG 1). Peripheral ANCA with antimyeloperoxidase specificity [p-ANCA (MPO)] was positive. Bronchoalveolar lavage revealed greater than 80% hemosiderin laden macrophages. Lung biopsy showed mild capillaritis and renal biopsy disclosed proliferative glomerulonephritis with crescent. He was diagnosed with microscopic polyangiitis. Treatment with pulse steroid and Rituximab was started with good clinical response, stabilization of renal function and improvement of inflammatory markers, p-ANCA and MPO titers. Pulmonary function tests remained stable.
DISCUSSION: ANCA associated vasculitides (AAV) are rare in childhood.1 Microscopic polyangitis is a systemic small-vessel vasculitis primarily associated with necrotizing glomerulonephritis and pulmonary capillaritis. Pathophysiology is based on autoantibodies activating proinflammatory phenotype of neutrophils that cause necrotizing damage to vascular walls.1 The presence of the p-ANCA and the MPO antibody are helpful in making the diagnosis of MPA. Biopsy of the involved tissue is often recommended to look for evidence of vasculitis. The introduction of cyclophosphamide (CYC) and high-dose glucocorticoids for AAV has allowed a reduction in 1-year mortality from 80% to 10-20%.2 CYC has side effects notable for malignancy and infertility. Rituximab (RTX) is a chimeric monoclonal antibody that interrupts antibody-mediated autoimmune disease by depleting precursors beyond ANCA producing cells.2 RTX appears more favorable than CYC in terms of safety. Furthermore, studies have shown that patients with AAV and renal involvement respond similarly to remission induction with RTX as with CYC.
CONCLUSIONS: MPA is a rare disease in children which has poor prognosis in the absence of aggressive therapy. CYC and high dose glucocorticoids reduce relapse and mortality rate. However, RTX is now an approved alternative for remission induction, and is increasingly used to treat patients with relapsing or refractory disease given its similar remission rate and favorable side effect profile.
Reference #1: Ameur S, Niaudet P, Baudouin V, Bourgeois M, Houdouin, V, Delacourt C, Hadchouel, A. Lung Manifestations in MPO-ANCA Associated vasculitides in Children. Pediatric Pulmonology 2014; 49: 285-290
Reference #2: Jones R. Rituximab in the Treatment of ANCA-Associated Vasculitis. Nephrology Clin Pract 2014; 238: 243-249
DISCLOSURE: The following authors have nothing to disclose: Grace Winningham, Wendy Estrellado
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