急性肝炎様に発症したPBC-AIH overlapの一例 | A Case of Primary Biliary Cirrhosis-Autoimmune Hepatitis Overlap Syndrome with Clinical Features of Acute Hepatitis

〔症例報告〕

急性肝炎様に発症したPBC-AIH overlapの一例

阿部　和道，大平　弘正，横川　順子
滝口　純子，雷　　　毅，宍戸昌一郎，高橋　敦史
小原　勝敏，佐藤由紀夫

福島県立医科大学医学部内科学第二講座

(受付　2004年7月23日)

A Case of Primary Biliary Cirrhosis-Autoimmune Hepatitis Overlap Syndrome with
Clinical Features of Acute Hepatitis

KAZUMICHI ABE, HIROMASA OHIRA, JUNKO YOKOKAWA,
JUNKO TAKIGUCHI, TSUYOSHI RAI, SHOICHIRO SHISHIDO, ATSUSHI TAKAHASHI,
KATSUTOSHI OBARA and YUKIO SATO

Dapartment of Internal Medicine II, Fukushima Medical University School of Medicine, Fukushima

要旨: 症例は49歳男性。2002年5月頃から全身倦怠感，尿黄染が出現し近医を受診。血液検査にてAST 472 IU/l，ALT 499 IU/l，TB 5.2 mg/dlと肝機能障害を認め，急性肝炎の診断にて同院に入院した。入院時，肝炎ウイルスマーカー陰性，抗核抗体320倍，抗ミトコンドリア抗体陰性，IgG 2,313 mg/dl，IgM 203 mg/dlであった。黄疸の遷延があり6月18日，精査加療目的に当科紹介入院となった。入院時AST 122 IU/l，ALT 128 IU/l，ALP 469 IU/l，gGTP 159 IU/l，TB 5.1 mg/dl，IgG 2,360 mg/dl，IgM 198 mg/dl，抗平滑筋抗体陽性，抗ミトコンドリアM2抗体陰性，抗SS-A抗体，抗SS-B抗体共に陽性であった。ウルソデオキシコール酸600 mg/dayを投与したが肝機能の改善は得られなかった。肝生検にて，門脈域の炎症細胞浸潤，piecemeal necrosis，線維性拡大を認め慢性活動性肝炎の所見と慢性非化膿性破壊性胆管炎像を認めた。Western blot法にてPDC-E2抗体が陽性であり，PBC-AIH overlapと診断した。また，唾液分泌低下，口唇生検所見よりシェーグレン症候群の合併と診断した。本例ではプレドニソロンとアザチオプリンの投与にて肝機能の改善が認められた。

索引用語: PBC-AIH overlap，PDC-E2抗体，Western blot法，シェーグレン症候群

Abstract: We report here a 49-yr-old man who had primary biliary cirrhosis (PBC)-autoimmune hepatitis (AIH) overlap syndrome with clinical features of acute hepatitis.　He had noticed general fatigue and yellowish urine from the beginning of May in 2002.　On May 14, he was admitted to a hospital because of liver dysfunction (aspartate aminotransferase ［AST］, 472 IU/l;alanine aminotransferrase ［ALT］, 499 IU/l;total bilirubin ［TB］, 5.2 mg/dl).　On admission, results of serum tests for hepatitis A, B, C were negative.　IgG level was elevated (2,313 mg/dl), but IgM level was normal.　Assay for anti-nuclear antibodies (ANA) was positive (×320), but antimitochondrial antibody (AMA) was negative.　He was referred to our department on June 18 because of prolonged jaundice.　The results of laboratory examinations were as follows: AST, 122 IU/l;ALT, 128 IU/l;alkaline phosphatase ［ALP］, 469 IU/l;TB, 5.1 mg/dl;and serum IgG, 2,360 mg/dl.　Anti-smooth muscle, SS-A, and SS-B antibodies were positive.　He was treated with ursodeoxycholic acid (UDCA, 600 mg/day), but his liver function did not improve.　Histological examination of a liver biopsy sample revealed chronic nonsuppurative destructive cholangitis (CNSDC) with piecemeal necrosis and fibrosis in the portal tracts.　He was diagnosed as having PBC-AIH overlap syndrome based on histological findings and detection of anti-pyruvate dehydrogenase complex-E2 antibody by Western blot analysis.　He was also diagnosed as being complicated with Sjögren syndrome based on the findings of degradation of salivary gland secretion and lip biopsy findings.　His liver function was improved by treatment with prednisolone and azathioprine.

Key words: PBC-AIH overlap，PDC-E2 antibody，Western blot analysis，Sjögren syndrome