A review of pediatric vasculitis with a focus on juvenile polyarteritis nodosa

Kawasaki disease or polyarteritis nodosa: coronary involvement, a diagnostic conundrum

Polyarteritis nodosa (PAN) is a medium-vessel vasculitis presenting with cutaneous and multisystem involvement with considerable morbidity. The necrotizing vasculitis in PAN typically involves renal, celiac, and mesenteric vascular beds. Coronary artery involvement is a characteristic feature of Kawasaki disease, another medium-vessel vasculitis; however, it has been rarely reported with PAN. Here, we present 2 cases with PAN involving coronaries mimicking Kawasaki disease. A 3.5-year-old boy with classical features of Kawasaki disease with giant coronary aneurysm refractory to IVIg, methylprednisolone, infliximab presented with persistent rise in inflammatory markers and gastrointestinal bleeding. Digital subtraction angiography (DSA) revealed celiac artery branches stenosis and beading suggestive of PAN. Another 2-year-old girl presented with persistent fever, abdominal pain, and distension. She had hypertension, hepatomegaly, and splenomegaly on examination. Echocardiography revealed multiple coronary aneurysms and DSA revealed numerous renal artery aneurysms. Coronary aneurysm although is a rare presentation of childhood PAN, and can mimic Kawasaki disease. Although both are medium-vessel vasculitis differentiation between these two entities is pivotal, as there are differences in treatment modalities, duration of immunomodulatory therapy, and the outcome. This manuscript describes the salient differences which can help differentiate PAN masquerading as Kawasaki disease at initial presentation.

Vasculitis: Kids are not just little people

Cutaneous vasculitis, inflammatory destruction of blood vessels, can present with a wide range of clinical and pathologic findings across a number of heterogeneous conditions. Although some vasculitides are present in both children and adults, some important differences exist in clinical presentation, etiology, management, and prognosis in childhood vasculitis versus adult vasculitis. Cutaneous vasculitis is rare in children, and most childhood vasculitides, of which Henoch-Schönlein purpura is the most common, histologically are small vessel leukocytoclastic vasculitis. In children, infectious etiologies are more common than in adults. Childhood cutaneous vasculitis is most often self-limited with a good prognosis, and treatment is mainly supportive. © 2017 Elsevier Inc. All rights reserved.

Cutaneous polyarteritis nodosa

Polyarteritis nodosa is a rare vasculitis in children characterized by necrotizing inflammation in small and medium size arteries. It is classified into systemic and cutaneous PAN according to the presence of systemic symptoms or visceral involvement. We describe the case of a 14-year-old girl with cutaneous Polyarteritis nodosa with an atypical clinical presentation.

Goldenhar Syndrome Associated with Extensive Arterial Malformations

Goldenhar Syndrome is characterized by craniofacial, ocular and vertebral defects secondary to abnormal development of the 1st and 2nd branchial arches and vertebrae. Other findings include cardiac and vascular abnormalities. Though these associations are known, the specific anomalies are not well defined. We present a 7-month-old infant with intermittent respiratory distress that did not improve with respiratory interventions. Echocardiogram suggested a double aortic arch. Cardiac CT angiogram confirmed a right arch and aberrant, stenotic left subclavian artery, dilation of the main pulmonary artery, and agenesis of the left thyroid lobe. Repeat echocardiograms were concerning for severely dilated coronary arteries. Given dilation, a rheumatologic workup ensued, only identifying few weakly positive autoantibodies. Further imaging demonstrated narrowing of the aorta below the renal arteries and extending into the common iliac arteries and proximal femoral arteries. Given a physical exam devoid of rheumatologic findings, only weakly positive autoantibodies, normal inflammatory markers, and presence of the coronary artery dilation, the peripheral artery narrowings were not thought to be vasculitic. This case illustrates the need to identify definitive anomalies related to Goldenhar Syndrome. Although this infant's presentation is rare, recognition of specific vascular findings will help differentiate Goldenhar Syndrome from other disease processes.

Lysosomal-associated membrane protein-2 plays an important role in the pathogenesis of primary cutaneous vasculitis

OBJECTIVES

Recent research suggests that lysosomal-associated membrane protein-2 (LAMP-2) could be one of the target antigens in the pathogenesis of vasculitides. We established a transgenic rat model, env-pX rats, with various vasculitides including cutaneous vasculitis. Human primary cutaneous vasculitis includes cutaneous polyarteritis nodosa (CPN) and Henoch-Schönlein purpura (HSP). We measured serum anti-LAMP-2 antibody levels in morbid env-pX rats and injected anti-LAMP-2 antibody into premorbid env-pX rats. We further measured serum anti-LAMP-2 antibody levels in patients with CPN and HSP.

METHODS

Cutaneous vasculitis was observed in ∼30% of 6-month-old morbid env-pX rats. In contrast, these findings were rare in premorbid env-pX rats under 3 months old. We also examined 85 patients with CPN and 36 adult patients with HSP. Serum anti-LAMP-2 antibody levels were determined using ELISA. Premorbid env-pX rats under 3 months old were given an i.v. injection of anti-LAMP-2 antibody at day 0 and day 7. At day 14, these rats underwent histopathological and direct immunofluorescence examination. Cell surface LAMP-2 expression of rat neutrophils was examined by flow cytometry.

RESULTS

Serum anti-LAMP-2 antibody levels were significantly higher in morbid env-pX rats than in wild-type normal rats. In addition, the levels in the cutaneous vasculitis group of morbid env-pX rats were significantly higher than the no cutaneous vasculitis group. Intravenous anti-LAMP-2 antibody injection into premorbid env-pX rats under 3 months old induced infiltration of neutrophils into cutaneous small vessels. Anti-LAMP-2 antibody-binding neutrophils were detected there. LAMP-2 expression on the cell surface of neutrophils in premorbid env-pX rats under PMA stimulation was higher compared with controls. Serum anti-LAMP-2 antibody levels in CPN and HSP were significantly higher than those of healthy controls.

CONCLUSION

These data support a positive relationship between anti-LAMP-2 antibody and cutaneous vasculitis.