Anti-neutrophil cytoplasmic antibodies and anti-endothelial cell antibodies.

Anti-neutrophil cytosolic antibodies (ANCA) and anti-endothelial cell antibodies (AECA) have been identified in a wide variety of disorders, but their pathophysiological role remains unclear. ANCA appear to be particularly associated with various forms of vasculitis including Wegener's granulomatosis. Kawasaki disease and microscopic polyarteritis. Cytoplasmic staining (cANCA) on indirect immunofluorescence is associated with extrarenal disease and a perinuclear pattern (pANCA) with renal limited disease. The cANCA antigen appears to be proteinase 3 and that for pANCA myeloperoxidase. AECA have been detected in systemic lupus erythematosus, scleroderma and dermatomyositis but are also found in systemic vasculitis, Kawasaki disease, haemolytic uraemic syndrome, thrombotic thrombocytopenic purpura and renal allograft recipients at the time of rejection. Their presence appears to be correlated with disease activity and they may be directed against epitopes on as yet unidentified infective agents that precipitate some of the diseases in which they are found that cross-react with antigenic sites exposed on endothelial cells. Measurement of these antibodies has a diagnostic role, facilitates monitoring of disease activity and may prove valuable in understanding the pathogenesis of the diseases in which they are found.