日本未熟児新生児学会雑誌　第24巻第1号　87～92頁（2012年）

日本未熟児新生児学会雑誌　24(1)：87-92；2012　

受付日：平成23．05．09

受理日：平成23．07．13

生後15日目に重症黄疸を呈し，eosin-5-maleimideを用いた赤血球膜band3 定量法にて診断し得た遺伝性球状赤血球症の早産児例

A Case of Premature Newborn Developed Severe Jaundice on 15th Day After Birth Due to Hereditary Spherocytosis： Efficacy of Eosin-5-Maleimide Binding Test in Newborn Period

鳥取大学　医学部　周産期・小児医学分野

Division of Pediatrics and Perinatology, Tottori University Faculty of Medicine

美野陽一・坂田晋史・宮原史子・松下博亮・中川ふみ・堂本友恒・三浦真澄・船田裕昭・長田郁夫・神﨑　晋

Yoichi MINO，Shinji SAKATA，Fumiko MIYAHARA，Hiroaki MATSUSHITA，Fumi NAKAGAWA， Tomotsune DOHMOTO，Mazumi MIURA，Hiroaki FUNATA，Ikuo NAGATA，Susumu KANZAKI

Key Words：hereditary spherocytosis，eosin-5-maleimide，band 3 protein，premature newborn，exchange transfusion

　赤血球膜蛋白異常により溶血を来す遺伝性球状赤血球症（以下HS）は新生児期に早発黄疸として発症することが多いが，新生児早期を過ぎても急激に重症黄疸や貧血として発症することもあり経過は一様でない。私達は生後15日目に貧血の進行と交換輸血（以下ET）を必要とする黄疸として発症し，eosin-5-maleimide（以下EMA）を用いた赤血球膜band3定量法にてHSと診断し得た早産極低出生体重児例を経験したので報告する。症例は在胎27週2日，体重1,060gで出生した男児。日齢1より黄疸を認め断続的に光線療法を行ったが，貧血はなかった。日齢15に血清ビリルビンの急上昇，貧血の急速な進行があり溶血性黄疸と診断，ETを施行した。EMAを用いた赤血球膜band3定量法にてEMA結合能の有意な低下を認め，HSと診断できた。近年HSの診断にEMAを用いたband3定量法が感度，特異度ともに優れた検査として報告されている。本法は微量の検体でも施行でき，低体重児症例での診断に期待される。

　Hereditary spherocytosis（HS）causes hemolysis due to the abnormality of red blood cell membrane protein and often manifests as jaundice of the early time of newborn. The clinical course of HS in newborn period is different, and in some cases HS suddenly developed severe jaundice and anemia after early stage of newborn. Recently eosin-5-maleimide （EMA）binding test is used as new diagnostic tool of HS. We report a HS case of premature newborn with very low birth weight who developed progressive anemia and jaundice on 15th day after birth and needed exchange transfusion （ET）for severe jaundice. Diagnosis of HS was confirmed by EMA binding test. The patient was born at 1,060g in weight for 27 weeks 2 days of gestation. We performed phototherapy intermittently on a day after birth for jaundice, but significant anemia could not be recognized. On 13th day he suffered respiratory disorder, and serum levels of unbound bilirubin were significantly elevated. As we diagnosed hemolytic jaundice at that time, we performed ET. The values of band 3 of the EMA binding protein of this case and his father were significantly lower than normal. Therefore we diagnosed as HS that was transmitted from father. Recently EMA binding test is reported useful diagnostic tool for HS because both sensitivity and specificity of this test were excellent. Additionally EMA binding test needs extremely small amount of serum. This test is useful as diagnostic tool of HS even for low birth weight infant.