This thesis focuses on renal involvement in ANCA-associated vasculitis (AAV), also named as ANCA-associated glomerulonephritis (AAGN). The studies mainly focus on clinico- and histopathologic... Show moreThis thesis focuses on renal involvement in ANCA-associated vasculitis (AAV), also named as ANCA-associated glomerulonephritis (AAGN). The studies mainly focus on clinico- and histopathologic parameters that are predictive for renal outcome. Predictive parameters for renal relapse in the native kidney are the histopathological classification of AAGN and interstitial infiltrates. The histopathological classification of AAGN is validated and the interobserver variability is investigated. It shows that this classification is predictive for renal outcome regarding the focal and sclerotic class, but needs more refinement for the crescentic and mixed class. The interobserver agreement between pathologists for this classification was moderate. Regarding renal transplantation, this thesis shows that this is a viable treatment option in patients with end-stage renal failure due to AAGN. The risk of renal disease recurrence in the renal graft is low, but once it has occurred, the risk of graft loss is considerable. In addition, this thesis presents an optimized assay for detecting anti-plasminogen autoantibodies in patients with AAV. The presence of these autoantibodies is validated in a cohort. The detection of these autoantibodies is important, because their presence seem to have a predictive value for renal outcome. This thesis also gives an overview of the clinical presentation, diagnosis and management of AAV. Show less
