Prevalence of ANCAs in patients on maintenance haemodialysis.

ANCA analysis as evaluated by concomitant determination of ANCA-IF, PR3-AB and MPO-AB in a larger cohort of dialysis patients disclosed that the prevalence of Wegener's granulomatosis and microscopic polyarteritis in Germany is 4 fold higher than hitherto believed. Low ANCA-IF titers without measurable PR3-AB or MPO-AB are not pathological- they resemble an increased autoimmune tendency of the dialysis patients. According to the european dialysis and transplantation association (EDTA)-registry the incidence of Wegener's granulomatosis (WG) and microscopic polyarteritis (MP) on haemodialysis (HD) in Germany is 0.5% and the prevalence is in the same range (1). In contrast to Germany the incidence in France and Great Britain is above 2%. This is mainly based on histologically proven diseases, which can identify only 1/3 of all affected cases, corresponding to our own experience. With the advent of ANCA serology, WG and MP can be diagnosed more easily. C-ANCA with proteinase 3-antibodies (PR3-AB) is typical of WG, and p-ANCA with myeloperoxidase-antibodies (MPO-AB) is typical of MP in our country. Since a considerable number of patients are on chronic HD without knowledge of their underlying renal disease we studied the prevalence of ANCAs in a larger cohort of HD patients.