Development of Nephritis and Abnormal Lung Shadow in a Patient with IgG4-related Hypertrophic Pachymeningitis with MPO-ANCA Positivity after Unplanned Interruption of Maintenance Glucocorticoid Therapy

Abstract

We herein report a patient with immunoglobulin (Ig)G4-related hypertrophic pachymeningitis (HP) with myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) positivity without renal dysfunction at the time of the diagnosis who subsequently developed nephritis after an unplanned interruption of maintenance glucocorticoid therapy. A renal biopsy specimen obtained at the time of the development of renal dysfunction revealed the possibility of both ANCA-associated nephritis and IgG4-related tubulointerstitial nephritis, with no HP relapse. The present case highlights the need to monitor other organ complications, including renal damage, in patients with IgG4-related HP with MPO-ANCA positivity, even after achieving remission.