The treatment of renal limited
systemic vasculitis usually involves a combination of cytotoxic drugs and
steroids. As shown by randomised prospective controlled trial,
plasmapheresis may be of additional benefit for the management of patients with renal involvement severe enough to require dialysis support. Recently, growing evidence has suggested that
autoantibodies to neutrophil cytoplasm (
ANCA) may play a role in the pathogenesis of the primary
vasculitides by promoting neutrophil mediated endothelial cell cytotoxicity. This has led to new strategies for treatment based on firstly, the use of semi-specific immunoabsorption (IA) devices to remove circulating
autoantibodies, and secondly, the use of 'Humanised'
monoclonal antibodies (MAbs) with specificity for lymphocytes, particularly T lymphocytes. We have treated four patients, two with
ANCA specificity for
proteinase 3 (PR3), and two with specificity for
myeloperoxidase (MPO). Semi-specific IA was carried out by
plasmapheresis through extracorporeal online devices, using
L tryptophan as the immobilised immunoabsorbant. Of the four patients who received IA, three showed substantial depletion in
ANCA titres and resolution of clinical symptoms. The MAbs were subsequently used to attempt to obtain long-term control of
ANCA synthesis. These results suggest that an optimal strategy for treatment of
systemic vasculitis might consist of specific IA, using immobilised
ANCA antigens to deplete circulating vasculotoxic
antibodies, combined with MAb
therapy to restore immune homeostasis.