It has been shown previously that proteinase 3 (PR3), a neutrophil intracellular protease that
is the main antigen of antineutrophil cytoplasm (ANCA) autoantibodies, is present on the
plasma membrane of a subset of freshly isolated neutrophils. This study shows that the size
of this subset of membrane PR3-positive (mPR3+) neutrophils is a stable feature of a given
individual, most likely genetically controlled. It ranges from 0 to 100% of neutrophils and
allows us to define a new polymorphism in the healthy population, with three discrete …