Human parvovirus B19による血球貪食症候群とウイルス性心筋炎を合併した成人の遺伝性球状赤血球症  [in Japanese] Human parvovirus B19-induced hemophagocytic lymphohistiocytosis and myocarditis in an adult patient with hereditary spherocytosis  [in Japanese]

<p>Human parvovirus B19（HPV B19）は血球貪食症候群（HLH）の原因として知られている。成人の遺伝性球状赤血球症（HS）患者のHPV B19によるHLHを経験した。患者は35歳女性。発熱，下痢を発症し，検査で重度の汎血球減少，中性脂肪・フェリチン高値，末梢血の目視像に球状赤血球を認めた。末梢血のHPV B19の増加，骨髄検査での血球貪食像により，HS患者のHPV B19によるHLHと診断した。これらの症状は保存的加療，輸血により1週間程で改善を認めたが，新たに心不全症状，心エコーでびまん性の壁運動低下を認め，HPV B19のウイルス性心筋炎の合併と診断した。利尿薬による保存的加療で心不全症状は2週間程で改善した。成人のHS患者のHPV B19は稀にHLHを合併し重症化するが保存的加療で改善しうる。しかし，心筋炎の合併を生じる可能性があり，HLH改善後も注意深い経過観察が求められる。</p>

<p>Human parvovirus B19 (HPV-B19) causes hemophagocytic lymphohistiocytosis (HLH). Here we describe a 35-year-old female with hereditary spherocytosis (HS) who developed HLH due to HPV-B19 infection. Upon admission, she had high fever and diarrhea. Laboratory findings included severe pancytopenia and elevated serum triglyceride and ferritin levels. Moreover, high HPV-B19 levels in the peripheral blood and increased reactive lymphocytosis in the bone marrow led to a diagnosis of HLH due to HPV-B19 infection. With supportive therapy and a blood transfusion, HLH symptoms, including fever and myelosuppression, improved in 1 week. However, symptoms of heart failure (HF) suddenly developed, and an echocardiography revealed diffuse systolic dysfunction, suggesting viral myocarditis due to HPV-B19 infection. Conservative management with diuretics gradually improved HF symptoms over a period of 2 weeks. HPV-B19 infection in adult patients with HS rarely results in severe HLH, but conservative therapy may improve the symptoms. Nonetheless, a careful follow-up is required after HLH improves because viral myocarditis can develop, as was seen in our patient.</p>