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The precise mechanism of prolonged thrombocytopenia following living donor liver transplantation (LDLT) remains unclear. To determine risk factors associated with prolonged thrombocytopenia following LDLT, with a focus on the activity of ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type-1 motifs member 13) and the influence of splenectomy. Adult LDLT patients were divided into two groups on the basis of platelet counts (100 × 10(3)/μL) on POD 14: high and low platelet (HP and LP) groups. Survival analysis was performed in the 100 patients, and ADAMTS13 activity and von Willebrand factor (VWF) levels in the plasma were measured in 65 adult recipients. The 6-month survival rate was significantly lower in the LP group (n = 36) than in the HP group (n = 62) (61.1 vs. 93.5 %). ADAMTS13 activity had been significantly lower in the LP group (n = 23) than in the HP group (n = 42). The VWF/ADAMTS13 ratio was significantly higher in the LP group than in the HP group. The independent risk factors for thrombocytopenia on POD14 were preoperative AT levels and ADAMTS13 activity on POD14. TPO levels on POD14 were significantly higher in the LP group than in the HP group, while those on POD28 in the LP group were significantly decreased, despite the low platelet levels. Irrespective of splenectomy, platelet counts and ADAMTS13 activity in the LP group remained low until POD28, while VWF/ADAMTS13 ratio significantly increased until POD28. These results suggest that prolonged thrombocytopenia after LDLT was associated with not only a decrease in ADAMTS13 due to sinusoidal endothelial cell injury, but also low TPO production due to hepatocyte dysfunction, irrespective of splenectomy [corrected].

The precise mechanism of prolonged thrombocytopenia following living donor liver transplantation (LDLT) remains unclear. To determine risk factors associated with prolonged thrombocytopenia following LDLT, with a focus on the activity of ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type-1 motifs member 13) and the influence of splenectomy. Adult LDLT patients were divided into two groups on the basis of platelet counts (100 × 103/μL) on POD 14: high and low platelet (HP and LP) groups. Survival analysis was performed in the 100 patients, and ADAMTS13 activity and von Willebrand factor (VWF) levels in the plasma were measured in 65 adult recipients. The 6-month survival rate was significantly lower in the LP group (n = 36) than in the HP group (n = 62) (61.1 vs. 93.5 %). ADAMTS13 activity had been significantly lower in the LP group (n = 23) than in the HP group (n = 42). The VWF/ADAMTS13 ratio was significantly higher in the LP group than in the HP group. The independent risk factors for thrombocytopenia on POD14 were preoperative AT levels and ADAMTS13 activity on POD14. TPO levels on POD14 were significantly higher in the LP group than in the HP group, while those on POD28 in the LP group were significantly decreased, despite the low platelet levels. Irrespective of splenectomy history, platelet counts and ADAMTS13 activity in the LP group remained low until POD28, while VWF/ADAMTS13 ratio significantly increased until POD28. These results suggest that prolonged thrombocytopenia after LDLT was associated with not only a decrease in ADAMTS13 due to sinusoidal endothelial cell injury, but also low TPO production due to hepatocyte dysfunction, irrespective of history of splenectomy.

症例は80歳男性．近医で軽度の肝機能異常を指摘され，腹部超音波検査を受けたところ膵体部に20mm大の内部エコー均一な低エコー腫瘤を指摘され当院に精査入院．造影CTでは，膵体部に動脈相で造影効果に乏しく，門脈相で腫瘍辺縁部に軽度の造影効果を示す20mm大の腫瘍を認め，FDG-PETでは，SUV 3.3と軽度の集積を認めた．内分泌腫瘍を疑い血中膵ホルモンを測定するとグルカゴンが610pg/ml と上昇していた．確定診断のためにEUS-FNABを施行した．組織所見では内分泌腫瘍と考えられ，免疫染色でグルカゴン陽性であった．無症候性グルカゴノーマの診断で，腹腔鏡補助下に脾合併膵体尾部切除を行った．切除標本では，25mm大の白色調腫瘍を認め，免疫染色でグルカゴン陽性であり，また脾動脈周囲リンパ節転移を認め，well differentiated endocrine carcinoma（glucagonoma）と診断された．術後3年の現在再発無く元気である．

われわれは膵頭部に発生し，膵腫瘍との鑑別が困難であった神経鞘腫の1例を経験したので報告する．症例は75歳，男性．泌尿器科にてPSA高値にて通院中，腹部CTにて膵頭部腫瘍を認め当科紹介となった．CTにて膵管の拡張はないものの，膵鈎部に6.5cm大のcystic tumorを認め，一部に造影効果のある壁在結節を認めた．MRIにては主膵管との交通は不明であったが，CT同様に，壁在結節を認めた．AngiographyにてSMA，SMV，門脈のencasementは認めなかった．また，celiac artery，SMA造影にて明らかなtumor steinは認めなかったが，SMA造影にてやや壁在結節は造影効果を認めた．以上より，悪性腫瘍の否定できず，PpPDを施行．摘出標本で膵神経鞘腫と診断された．膵神経鞘腫は比較的稀な疾患であり，本邦報告例31例の文献的考察も加え報告する．