The Successful Treatment of Myeloperoxidase Antineutrophil Cytoplasmic Antibody-positive Hypertrophic Pachymeningitis in Patients with the Limited Form of Granulomatosis with Polyangiitis Using Methotrexate: Two Case Reports.

Recent findings have indicated a close relationship between myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-positive hypertrophic pachymeningitis and the limited form of granulomatosis with polyangiitis (GPA). In Japan, MPO-ANCA-positive hypertrophic pachymeningitis predominantly occurs in elderly individuals. We herein describe the cases of two patients with MPO-ANCA-positive hypertrophic pachymeningitis associated with the limited form of GPA who were successfully treated with a combination of corticosteroids and methotrexate. Although methotrexate has been shown to be less effective than cyclophosphamide for inducing the remission of GPA in patients with organ-threatening diseases, its safety and efficacy may make it a useful alternative treatment modality for patients with the limited form of GPA who show meningeal involvement.