High proteinase 3-anti-neutrophil cytoplasmic antibody (ANCA) level measured by the capture enzyme-linked immunosorbent assay method is associated with decreased patient survival in ANCA-associated vasculitis with renal involvement.

Wegener granulomatosis (WG) and microscopic polyangiitis (MP), diseases associated with antineutrophil cytoplasmic antibodies (ANCA), had an extremely poor prognosis before the introduction of cyclophosphamide and corticosteroids for their treatment. However, there is still reduced patient survival, and some studies have documented severe side effects of the immunosuppressants used. This 10-yr follow-up study assessed 117 consecutive patients with WG or MP with biopsy-confirmed renal involvement. The cumulative relative patient survival was lower: 0.664 for women and 0.648 for men. The causes of death (n = 64) were in most cases registered as associated with the vasculitic disease. Analysis of possible predictive factors for patient survival by multiple Cox regression analysis revealed that a very high level of proteinase 3 (PR3)-ANCA measured by the capture ELISA method, a diagnosis of MP, and older age were factors predicting poorer patient survival. High levels of B-thrombocytes at time of diagnosis were associated with a better prognosis. For patients surviving the first year, remission-sustaining therapy with azathioprine for longer than 12 mo was associated with improved patient survival. Thirty-nine patients developed end-stage renal failure. Elevated serum creatinine at time of diagnosis and a very high level of PR3-ANCA by capture ELISA were factors predicting a higher risk for renal failure during follow-up. The epitope on PR3 assessed by capture ELISA needs to be further analyzed and explored: it seemed to implicate poorer patient and renal survival in WG or MP with renal involvement.