Sphingosine-1-phosphate (S1P) increased translocation of antineutrophil cytoplasmic antibody (ANCA) antigens on neutrophils. Human neutrophils were isolated and incubated with different concentrations of S1P for 30 minutes. mPR3 and myeloperoxidase (MPO) were measured with flow cytometry or by ELISA and compared with non-stimulated cells. (A) mPR3 expression compared with non-primed nertrophils. (B) mMPO expression compared with non-primed nertrophils. (C) MPO concentration compared with non-primed neutrophils. Bars represent mean ± SD of repeated measurements of neutrophils from five independent experiments and donors.