僧帽弁置換術後の遅発性溶血性輸血副作用の1例

Delayed Hemolytic Transfusion Reaction after Mitral Valve Replacement：Report of a Case

はじめに　遅発性溶血性輸血副作用（delayed hemolytic transfusion reaction：DHTR）は，輸血後数日～十数日後に主に二次免疫応答によって増加した免疫グロブリンGの不規則抗体が原因で引き起こされる溶血性副作用である．原因となる不規則抗体の中には輸血前に交差適合試験や不規則抗体スクリーニング試験の検出感度以下となっているものも存在し，その発症を予測するのは困難である1，2）．われわれは僧帽弁置換術後に陽転化した不規則抗体であるJkb抗体によるDHTRを経験したので，文献的考察を加えて報告する．

We report a case of delayed hemolytic transfusion reaction （DHTR） after mitral valve replacement （MVR）. A 67-year-old woman with a history of blood transfusion （BT） was admitted for MVR. Preoperative laboratory test proved to be negative for irregular antibodies except anti-Dia. She underwent MVR using a mechanical prosthesis and compatible blood products were transfused perioperatively. On post-operative day 13, she developed hemoglobinuria and anemia with elevated serum total bilirubin and lactic dehydrogenase levels. Transesophageal echocardiography showed trivial transvalvular leakage. Laboratory test successfuly identified another irregular antibody, anti-Jkb antibody. The patient had Jkb negative BT and did not need re-operation. Later, she recovered with no signs of hemolysis. Since anti-Jkb antibody gets undetectable within a few months, it is difficult to find out before surgery. As hemolysis following cardiac surgery is more commonly associated with prostheses and extracorporeal circulation than DHTR. Physicians should, however, be aware of this unusual complication especially in patients who underwent BT.