Systemic vasculitis (SV) pathogenesis is majorly identified by the inflammation of different blood vessel walls, and the resulting morphological changes. Arteries and veins can both be affected simultaneously. The clinical manifestation is mainly indicated by general symptoms like exhaustion, fever and weight loss. Depending on which kind of vessels are affected, future disease course varies.

Anti-neutrophil cytoplasmic antibodies (ANCA) play an essential role in the serological diagnosis of SV. These antibodies are usually determined by indirect immunofluorescence using ethanol fixed human neutrophils. Cytoplasmic ANCA (cANCA) and perinuclear ANCA (pANCA) are distinguished based on the immunofluorescence pattern. Cell fixation using ethanol destroys granular membranes in neutrophil cytoplasm, thus allowing positively charged proteins move to the negatively charged nucleus – the basis for ANCA screening substrate. cANCA antibodies are identified by a cytoplasmic fluorescence pattern, whereas pANCA antibodies must be differentiated from antibodies to nuclear antigens (ANA) which also show a (peri) nuclear pattern.