Журнал «Здоровье ребенка» 8 (59) 2014

Introduction.

Classification of vasculitis is one of the most difficult problems in rheumarology [1]. Chapel Hill Сonsensus in 1994 year introduced the concept of ANCA-associated vasculitis because of the involvement of anti-neutrophil cytoplasmic antibodies (ANCA) as the common pathogenesis [2, 3]. Vasculitis associated with antineutrophil cytoplasmic antibodies specific to proteinase 3 (PR3-ANCA)) includes Wegener's granulomatosis, specific to myeloperoxidase (MPO-ANCA) includes microscopic polyangiitis (MPA), idiopathic necrotizing crescentic glomerulonephritis  and Churg-Strauss syndrome [4].  The classic form of MPA is necrotizing vasculitis affecting small vessels. MPA generally presents as a life- and organ-threatening disease. Necrotizing glomerulonephritis is common. Pulmonary capillaritis often occurs [1].  Indolent Wegener’s granulomatosis has been described previously [5].  Two cases of unusually indolent MPO-ANCA has been described in adult [6].

The aim of our study was to show the unusual course of MPO-ANCA associated vasculitis without  renal and lungs involvement.

Case report. We observed a case of indolent course of MPO-ANCA associated vasculitis, with limited progression over few years in girl of 15 years. The current illness began about 6 years ago (in 2008) with recurrent episodes of sinusitis and conjunctivitis, in 2010 – one episode of arthritis and skin hand edema.

In 2012 the episodes were increasing in frequency after streptococcal infection with sinusitis and conjunctivitis, migratory arthritis/arthralgia, skin abnormalities (urticarial rash, angioedema, subcutaneous nodules on elbows, purpura), hoarseness of voice, myalgia, cardiac involvement (extrasystoles), weight loss (5 kg during 1 month). Autoimmune tyroiditis was found. The girl had no pulmonary or renal manifestations. Laboratory examination revealed elevated C-reactive protein level, ESR, ASL-O and seromucoid. The pANCA pattern was detected in titer 1/640, MPO-ANCA by ELISA. ANA was negative, cryoglobulins were not detected, Hep B and C serology was negative, and complement levels—C3 was normal and C4 not much elevated, Ig E, Ig M and Ig G were normal, Ig A - elevated. Urinary sediment and creatinine levels have stayed normal. Skin biopsy revealed infiltration and edema of the dermis, mainly around capillaries, hemorrhage, collagen hyperproduction. The treatment with prednisone 1 mg/kg/day was prescribed.

During the treatment the state of girl has improved. She became more active, decreased clinical signs, MPO-ANCA titre became normal.

Discussion.

Usually MPO-ANCA associated vasculitis occurs in middle-aged adults, but some cases are reported in the pediatric population [7]. The difficulties of diagnosis in this case are in missing data for renal and lungs involvement. This case confirms the possibility of unusually indolent course MPO-ANCA associated vasculitis in children, without involvement of vital organs, that determine the severity of the disease and its consequences.

Due to the rarity of the disease, many countries held a register of all cases of ANCA-associated vasculitis in children. Thus, according to the North American ARChiVe, which included patients from 37 US/ Canadian sites from 2004 to 2010 were registered 155 children with ANCA-associated vasculitis [8], 18 (12%) of them had MPA. The median age at diagnosis was 13 (range 3–16) y. The most common features were renal (95%), constitutional (89%), pulmonary (28%) and sinus-upper respiratory (17%). Anti-MPO were present in 61% of patients.

Early treatment enables a favorable prognosis of MPO-ANCA-associated MPA in children [9].

Conclusion.

Despite the fact that the MPO-ANCA associated vasculitis occurring predominantly in middle-aged adults, in rare cases, it is common in children. Multifaceted and low specificity of symptoms makes difficult to diagnose it. We have described a case of the atypical the unusual course of MPO-ANCA associated vasculitis without renal and lungs involvement, but we can not exclude further involvement of the kidneys or lungs, that requiring careful monitoring of these patients.