Clinical significance of anti-neutrophil cytoplasmic autoantibodies in patients undergoing maintenance hemodialysis

In order to determine the clinical significance of anti-neutrophil cytoplasmic autoantibodies (ANCA) in patients undergoing maintenance hemodialysis, we examined myeloperoxidase specific ANCA (MPO-ANCA) and proteinase 3 specific ANCA (PR3-ANCA) by enzyme immunosorbent assay in 183 patients undergoing maintenance hemodialysis for more than a year. Eleven patients had ANCA, 8 with MPO-ANCA and 4 with PR3-ANCA including one with both MPO-ANCA and PR3-ANCA. These ANCA positive patients were divided into two groups (3 patients in A group and 9 in B group) by the history of rapidly progressive glomerulonephritic syndrome (RPGN). All of A group with RPGN had vasculitic syndrome at the start of hemodialysis. One had a relapse of pulmonary hemorrhage with MPO-ANCA after 3 years of uneventful maintenance hemodialysis without MPO-ANCA. Although the remaining 2 patients had MPO-ANCA continuously, they had no remarkable vasculitic syndrome during maintenance hemodialysis. B group, without RPGN, had no history of vasculitic syndrome. The pathogenesis of ANCA production in B group might be related to immunological abnormalities associated with chronic renal failure or maintenance hemodialysis. In ANCA positive patients undergoing maintenance hemodialysis with a history of RPGN, careful management to prevent the occurrence of vasculitic syndrome, especially pulmonary hemorrhage, is needed.