PRTN3 and systemic lupus erythematosus: After plasma exchange, 54% (7/13) had complete remission, and 46% (6/13) had partial remission. The European consensus lupus activity score (ECLAM) and systematic lupus activity index (SLEDAI) decreased to 1.2 and 3.9 respectively from 6.9 and 30.7.Disappeared upon head MRI examination, and consciousness level and mental state began to recover. The PR3-ANCA antibody decreased from 164 U/ml to 15.7 U/ml.