IgG4関連硬化性疾患による後腹膜線維症

A case of Retroperitoneal fibrosis caused by IgG4-associated multifocalsclerosis

77歳，男性。両側水腎症にて近医より紹介受診した。高IgG4血症を示す後腹膜線維症であり，IgG4関連硬化性疾患と考えられた。プレドニゾロン30mg/dayの投与を開始したところ，IgG4はすみやかに低下し症状も改善した。ステロイドを漸減し2.5mg/dayを維持量としたが，臨床的再燃なく経過している。IgG4関連硬化性疾患は全身の諸臓器に線維性硬化をきたす。後腹膜線維症をみた際には，全身疾患の1部分症状である可能性も考慮する必要がある。

A 77-year-old man was referred to our hospital for the close examination of bilateral hydronephrosis. CT scan indicated retroperitoneal fibrosis,and examination of blood showed elevated IgG4. There were no suspicious malignant findings. So we reached a diagnosis of retroperitoneal fibrosis related to IgG4-associated multifocal sclerosis. Predonisolone therapy in a dose of 30 mg daily was started. Thereafter,the level of serum IgG4 value had gradually decreased,and CT scan showed improved findings of retroperitoneal fibrosis. Predonisolone was subsequently taped off,and now in a maintenance dose of 2.5 mg daily. He has not presented relapse.