Anti-neutrophil cytoplasmic antibody positivity in five children with systemic lupus erythematosus--what is the importance of this finding?

Juvenile systemic lupus erythematosus (JSLE) is a systemic autoimmune chronic disease that can affect any part of the body. It is characterized by the formation of antibodies against nuclear antigens. Vasculitis may be found in SLE, but it scarcely complies with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) criteria. We report five cases of severe JSLE associated with AAV diagnosed between 1991 and 2013 in three university-based tertiary care centers. The patients (3 girls and 2 boys, aged 12 to 17) presented with a severe clinical picture and the following features: cytopenia (n=5), autoimmune hepatitis (n=3), lupus nephritis (n=1), pancreatitis (n=1), secondary antiphospholipid syndrome (n=2), impending respiratory failure (n=2), and gastrointestinal bleeding (n=1). All patients were proteinase 3 (PR3) ANCA positive, while two of them were myeloperoxidase (MPO) and PR3 ANCAs positive at the same time. They were treated with corticosteroids and immunosuppressive drugs. Remission of the disease was achieved in three patients. The course of the disease was worsening in two patients and we included rituximab (anti-CD20) in therapy. All of our patients presented as the most severe SLE patients, who must be diagnosed as soon as possible and treated very intensively. Since the comorbidity of JSLE and AAV occurs very rarely in children, presentation of such patients, their clinical pictures, treatment, and the course of the diseases are experiences that can be of great help.