Childhood microscopic polyangiitis associated with MPO-ANCA

Abstract

We reviewed the clinical, histological and serological parameters of microscopic polyangiitis (MPA) associated with antineutrophil cytoplasmic antibodies (ANCA) specific to myeloperoxidase (MPO). Six girls and one boy aged 12.0+/-2.6 years (7-15 years) met the following inclusion criteria: (1) clinical manifestations of systemic small vessel involvement; (2) histological demonstration of pauci-immune necrotizing glomerulonephritis; and (3) serological findings of increased concentration of MPO-ANCA by ELISA test. The main clinical manifestations were: influenza-like symptoms (100%), hematuria/proteinuria (100%), purpura (100%), pulmonary-renal syndrome (57%), acute renal failure (ARF) (29%), ischemic cerebral insults (29%), and necrotizing vasculitis of the skin (29%). All patients underwent renal biopsy examined by immunohistochemistry with expression of alpha-smooth muscle actin (alpha SMA) in glomerular and interstitial spaces. Patients were followed from 6 months to 5.5 years (35.4+/- 23.2 months). None of the patients died. Two of seven children who had ARF progressed to end stage renal disease; one developed chronic renal failure, and four normalized renal function. ARF and central nervous system involvement at presentation were parameters of poor renal outcome. A high score of fibro-cellular glomerular crescents was associated with worse prognosis. Early treatment enables a favorable prognosis of MPO-ANCA-associated MPA in children.

Clinical presentation and outcome of pediatric ANCA-associated glomerulonephritis

“…In the adult literature, it is reported that renal involvement in AAV can be so severe as to require dialysis-dependence in 23-60 % of these patients [15,16]. Our study found that 36 % of patients required dialysis at diagnosis, which is within the range previously reported in the pediatric literature as well [5,6,[10][11][12][13][17][18][19][20][21]. However, it is important to note that our study is based solely on those patients with renal involvement and does not include patients without renal involvement.…”

“…Similar to other childhood chronic diseases, children with AAV differ from adults in that they have a longer anticipated life span over which their disease must be managed. The peak age of onset of AAV in the pediatric population is during late childhood and adolescence, a critical time for growth as well as emotional, physical and reproductive development [4][5][6].…”

An 11-year-old girl with antineutrophil cytoplasmic antibody-associated glomerulonephritis identified by a school urinary screening program

“…As to prognosis, nine of 31 patients progressed to ESRD; of these nine patients, four required dialysis during the initial phase of therapy and did not recover renal function, three progressed to ESRD with episodes of relapse, and the remaining two progressed to ESRD without active disease or relapse [2]. Other studies have revealed that ANCA-associated GN progresses to renal failure in 20-40 % of patients; thus, it is important to identify patients with ANCA-associated GN and to manage treatment in the early stages of the disease [1,[3][4][5][6]. Our case was identified by SUS and was asymptomatic.…”

“…Although ANCA-associated GN is rare in childhood, there are a number of reviews of the clinical features and outcomes of pediatric ANCA-associated GN [2][3][4][5]. Hattori et al [2] reported that the clinical disease spectrum of ANCA-associated GN is similar in pediatric and adult patients and found that 29 % of patients with ANCAassociated GN progressed to end-stage renal disease (ESRD).…”

“…ANCAs were first reported by Davies in 1982 [1] in patients with pauciimmune necrotizing glomerulonephritis (GN) with crescents and are now regarded as a serologic marker for active pauci-immune necrotizing crescentic GN, either in the renally limited form or associated with systemic vasculitis, such as granulomatosis with polyangiitis, microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis [2][3][4][5][6].…”