日本未熟児新生児学会雑誌　第27巻第1号　94 ～ 98頁（2015年）

日本未熟児新生児学会雑誌　27(1)：94-98；2015　

受付日：平成25．11．21

受理日：平成26．09．16

血小板減少を呈した後天性CMV 感染症に対してガンシクロビル投与が有効であった超低出生体重児の1 例

Ganciclovir Administration for Treatment of Acquired CMV Infection in an Extremely-Low-Birth-Weight Infant Who Presented with Thrombocytopenia

＊ 1 長野県立こども病院　新生児科，＊ 2 長崎大学　医学部　小児科

＊1Division of Neonatology, Nagano Children’s Hospital, ＊2Department of Pediatrics, Nagasaki University School of Medicine

才田　謙＊1・関口和人＊1・高杉瑞恵＊1・溝上雅恵＊1・中村秀勝＊1・三代澤幸秀＊1・小久保雅代＊ 1・廣間武彦＊ 1・森内浩幸＊ 2・中村友彦＊ 1

Ken SAIDA＊1，Kazuhito SEKIGUCHI＊1，Mizue TAKASUGI＊1，Masae MIZOGAMI＊1，Hidekatsu NAKAMURA＊1，Yukihide MIYOSAWA＊1，Masayo KOKUBO＊1，Takehiko HIROMA＊1，Hiroyuki MORIUCHI＊2，Tomohiko NAKAMURA＊1

Key Words：cytomegalovirus（CMV），thrombocytopenia，platelet-associated IgG（PAIgG），immune thrombocytopenic purpura（ITP），ganciclovir（GCV）

　後天性サイトメガロウイルス（cytomegalovirus：CMV）感染症による血小板減少に対してガンシクロビル（ganciclovir：GCV）投与が有効であった超低出生体重児の1 例を経験した。症例は在胎22 週，体重501g で出生した男児。日齢36 にCRP 上昇を認め，日齢56 に血液および尿のCMV-PCR 陽性から後天性CMV 感染症と診断した。頻回の血小板輸血を必要とした。血小板関連IgG（platelet-associated IgG：PAIgG）の上昇から免疫性血小板減少性紫斑病（immune thrombocytopenic purpura：ITP）の可能性を考えた。免疫グロブリン投与に対する反応は乏しく，GCV 投与により血小板減少は改善し，輸血不要となった。CMV 感染と血小板減少の関連として，巨核球への直接的な障害あるいは免疫学的機序によるITP の報告があるが，本例では，GCV に対する良好な治療経過から，巨核球への直接障害の関与が大きいと考えられた。後天性CMV 感染症において血小板減少が顕著な場合，GCV の積極的な治療は選択肢になると考えられた。

　We experienced a case of an extremely-low-birth-weight（ELBW）infant who presented with thrombocytopenia due to acquired cytomegalovirus（CMV）infection. The infant weighed 501g at birth at 22 weeks of gestation. On day 36（postmenstrual age（PMA）, 28 weeks）, laboratory findings showed elevated C-reactive protein（CRP）levels. Antimicrobial agents were administered, but the CRP level remained slightly high. Polymerase chain reaction（PCR）to detect CMV in blood and urine yielded positive results at day 56（PMA, 30 weeks）, and a diagnosis of acquired CMV infection was made. The patient had thrombocytopenia and required frequent platelet transfusions. We postulated that the immune thrombocytopenic purpura（ITP）resulted from an increase in platelet-associated IgG（PAIgG） , and intravenous immunoglobulin（IVIG）was provided；however, the response was poor and neutropenia was also observed. Thereafter, ganciclovir（GCV）was given, and the thrombocytopenia improved. Subsequently, the patient did not require platelet transfusions. GCV is the main treatment provided for CMV, and this resulted in an improvement of thrombocytopenia. Some studies have reported an association between CMV infection and thrombocytopenia, and there are two main theories：One theory is the direct destruction of megakaryocytes by the CMV, and another is the induction of thrombocytopenic purpura by an immunological mechanism. In this case, the first theory was more plausible because of the observed response to GCV. Treatment adaptation for acquired CMV infection is controversial；however, aggressive treatment with GCV may be a good choice when remarkable thrombocytopenia is observed in patients with CMV infection.