Clinical characteristics of propylthiouracil (PTU) induced antineutrophil cytoplasmic antibodies positive cases; analysis of a case of PTU-induced ANCA positive patients with hyperthyroidism

Abstract

To study the clinical characteristics of propylthiouracil (PTU) induced antineutrophil cytoplasmic antibodies (ANCA) positive cases and increase the awareness of PTU induced ANCA positive vasculitis (APV). The clinical data of nine cases with positive ANCA induced by PTU in Peking Union hospital since 2000 were analyzed and literature review was conducted. (1) Nine patients with hyperthyroidism, at a mean age of 33.1 (16 approximately 51), who were treated with PTU for a mean period of 32.4 months (3 approximately 84); (2) Sera from nine cases were ANCA positive, and autoantibodies from six tested cases could recognize not only MPO, but also PR3, HLE, BPI and LF; (3) Six cases with high titer perinuclear ANGA (pANCA) (> or = 1:1280) were diagnosed APV and all had renal involvement (five confirmed by renal biopsies), three cases with low titer pANCA (< or = 1:320) had little clinical manifestations of vasculitis; (4) Eight patients stopped taking PTU when positive ANCA were noted. One case with APV got remission after stopping PTU, the other three APV were treated with glucocorticosteroid and immunosuppressive agents at meanwhile. Only one patient kept taking PTU for eighteen months without an increased titer of ANCA. PTU could induce production of ANCA. High titer of ANCA might suggest existence of APV and the titer would be associated with status of APV. Early withdrawal of PTU and administration of glucocorticosteroid and immunosuppressive agents based on renal pathology will greatly improve the prognosis.