Antineutrophil cytoplasmic antibodies in childhood systemic lupus erythematosus.

We aimed to evaluate the presence of peripheral antineutrophil cytoplasmic antibodies (p-ANCA) and cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA) in children with SLE and to correlate its association of laboratory findings. Twenty-one children with SLE were studied. Serum samples in patients were tested by indirect immunofluorescence (IIF) slide kit (INOVA) for c-ANCA and p-ANCA and by ELISA for myeloperoxidase (MPO-ANCA) and proteinase 3 (PR3-ANCA). All the patients but two were quiescent for lupus at the time of sampling. Sixteen of 21 patients showed positive IIF staining whereas only 5 had MPO-ANCA and 2 of nine PR3-ANCA. The data suggests that SLE may be associated p-ANCA directed against additional target antigens rather than MPO and may be implicated in the pathogenesis of SLE or may be only non-specific antibodies developed in lupus.