Retroperitoneal fibrosis as the presenting manifestation of IgG4-related disease in a patient previously diagnosed with granulomatosis with polyangiitis (Wegener's): One disease or two?

摘要

A 68-year-old man was diagnosed with granulomatosis with polyangiitis (GPA, or Wegener's granulomatosis) in 1997 based on arthritis, peroneal palsy, recurrent sinusitis, fever, and proteinase 3/anti-neutrophil cytoplasmic antibodies (PR3-ANCA) of around 100 U/L. Serum creatinine (s-creatinine), urinalysis, and chest X-ray were normal. A biopsy from the nasal mucosa showed plasma cell infiltration, scattered lymphocytes, and eosi-nophils. There was no granuloma, vasculitis, or fibrosis. Remission was achieved by three intravenous methyl-prednisolone pulses followed by oral prednisolone 17.5 mg/day, which was gradually tapered and discontinued after 1 year. Azathioprine (AZA) was withdrawn after 3 weeks due to a rash. Despite persisting PR3-ANCA seropositivity, the patient remained in complete clinical and drug-free remission until May 2012 when relapsing GPA was suspected due to nasal congestion,