大橋 篤

OBJECTIVES: In cell-free and concentrated ascites reinfusion therapy (CART), the protein recovery rate decreases when the filtration membrane gets clogged. Employing a device with a filtration membrane washing feature prevents clogging, but it leads to the loss of ascites within the filter, resulting in reduced protein recovery. This study employed a device with a membrane washing function to investigate the relationship between protein recovery rate and the quantity of washing solution used, depending on the selected washing method. METHODS: We analyzed cases of CART conducted at Fujita Health University Hospital between May 2021 and November 2022. The cases were divided and compared between two groups: one using flush and rinse as the washing method (flush+rinse group) and another using only flushing (flush group). RESULTS: We identified nine cases and 16 sessions. In the flush+rinse group, the median amount of washing solution used per membrane washing was 259 mL per cycle, whereas it was 54 mL per cycle in the flush group. This difference was statistically significant (p<0.0001). The median total protein recovery rate was 53.8% for the flush+rinse group and 78.8% for the flush group, with the latter showing a significantly higher value (p=0.0199). CONCLUSIONS: In CART using a membrane washing function, adopting a washing method that reduces the amount of washing solution leads to an increase in the total protein recovery rate.

Abstract Introduction Indoxyl sulfate (IS) is a protein‐bound uremic toxin that causes uremic sarcopenia. IS has poor dialysis clearance; however, the addition of a binding competitor improves its removal efficiency. Methods Dialysis experiments were performed using N‐acetyl‐l‐tryptophan (L‐NAT) instead of l‐tryptophan (Trp) using pooled sera obtained from dialysis patients. The molecular structures of L‐NAT and Trp were similar to that of IS. Therefore, we examined whether Trp and L‐NAT were involved in muscle atrophy in the same manner as IS by performing culture experiments using a human myotube cell line. Results The removal efficiency of L‐NAT was the same as that of Trp. However, L‐NAT concentrations in the pooled sera increased at the end of the experiment. Trp (1 mM) decreased the area of human myocytes, similar to IS, whereas L‐NAT did not. Conclusion L‐NAT is a binding competitor with the ability to remove protein‐bound IS while preventing sarcopenia.

Cell-free and concentrated ascites reinfusion therapy (CART) is performed by collecting the ascites from the patient, followed by filtration and concentration. Thereafter, concentrated cell-free ascites is reinfused into the patient intravenously. The new type of machine, Plasauto μ, for managing the process of CART was launched onto the market. We have evaluated the machine through postmarketing clinical study in 17 patients with malignant ascites. The amounts of original and concentrated ascites were 3673 ± 1920 g and 439 ± 228 g, respectively. Recovery rates were acceptable regarding values of total protein, albumin, and IgG that were 55.6% ± 17.3%, 60.2% ± 20.8%, and 58.2% ± 20.5%, respectively. Recovery rates were positively associated with amounts of original ascites and negatively associated with total protein concentration. No adverse events related to the machine were observed. The new type of machine showed preferable performance in processing malignant ascites.

Cell-free and concentrated ascites reinfusion therapy (CART) by internal filtration pressure method (internal method) and external filtration pressure method (external method) using the same cancerous ascites was performed. The rate of rise in circuit pressure and recovered components were compared between the two methods. The factors related to circuit pressure rise were also researched. In both methods, circuit pressure rose in 50% of cases. The recovery rates of IgG, IgA, IgM, and haptoglobin were significantly higher for the internal method than for the external method, whereas the recovery rate of α1 -antitrypsin was significantly lower in the internal method than in the external method. The levels of IL-6, haptoglobin, α1 -antitrypsin, and fibrinogen/fibrindegradation products (FDP) in the original ascites were significantly higher in the group wherein circuit pressure rose than in that without circuit pressure rise. These proteins might be related to the rise in circuit pressure.

血液透析療法における透析膜材質の違いによるC型肝炎ウイルス(HCV)吸着について検討した。対象は慢性維持血液透析中のHCV抗原陽性男性患者5名(平均年齢60.5歳、平均透析歴9.5年)で、原疾患は糖尿病性腎症、慢性糸球体腎炎各2名、腎硬化症1名であった。1)4種類の透析膜を用いて透析前・後のHCV抗原濃度とトランスアミナーゼ(AST、ALT)を測定したところ、各透析膜のHCV抗原濃度減少率はF-70S:32.7%、BK-1.6P:19.0%、FB-150E:10.4%、AM-FP1.3:8.8%といずれでも有意な減少が認められた。だが、翌週にはほぼ前値に復していた。2)AST、ALT値は全例が正常範囲で推移し、週変動は認めなかった。3)in vitroのHCV抗原吸着実験による各透析膜での減少率は、F-60S:25.8%、BK-1.3P:20.5%、FB-130U:16.0%、AM-FP1.3:10.5%で、HCV抗原の回収実験では各透析膜とも吸着実験で減少したHCV抗原量にほぼ同等の量であった。以上、血中のHCV抗原は透析膜で吸着除去されると考えられた。

銀は安全性が高いことと抗菌スペクトルが広いことからさまざまな分野で使用されている．今回，銀イオン（Ag⁺）水の殺菌性を次亜塩素酸ナトリウム（NaClO）と比較し，Ag⁺水の透析用消毒剤としての有用性を検討した．試験菌株としてPseudomonas aeruginosa，Escherichia coli，Staphylococcus aureusを用いて各消毒剤の最小殺菌濃度（MKC）を測定した．また，透析用水製造工程（原水，活性炭処理水，RO水），透析液ライン（Bタンク，透析液）から検出された細菌に対して各消毒剤の殺菌効果試験を行った．MKCの結果から，Ag⁺水はNaClOのような即効性は認められないが，長い時間作用させるとNaClOと同等の殺菌性を有することがわかった．特に透析用水製造工程で塩素消毒耐性の水棲菌の消毒についてはNaClOよりもAg⁺水は有効であると考えられる．また，Ag⁺水はグラム陰性菌以外にもグラム陽性菌に対しても殺菌力があり，NaClOに匹敵する透析用消毒剤として利用できる可能性がある．

血液透析の際にフタル酸ジエチルヘキシル量を測定し,ハイパフォーマンス膜(HPM)がDEHP除去に有用であった

出血性生病変を伴う慢性維持透析患者6名に再循環法による無抗凝固薬透析を試みたが, 血液回路特にドリップチェンバーを改良することにより支障なく施行できた. その際, 凝固線溶系に関する諸因子の変動を見たが, その成績に基づき各種膜材料の抗血栓性の評価も行った.<br>ヘパリンHD終了時のTAT値は, HD開始前に比し上昇しなかったが, 無抗凝固薬透析は前値に比し9.1倍の有意 (p<0.01) な上昇が見られた.<br>無抗凝固薬透析を行った場合, PC膜では, 透析によるTAT, 血小板減少率およびPF-4の変動が少なく, かつ, 透析終了時に全く残血を認めず, 最も抗血栓性に優れていると判定された.

エリスロポエチン (EPO) 投与による貧血の改善が, 投与前後の網赤血球 (RET) 率と赤血球 (RBC) 数の変動より予測可能かどうか検討した.<br>対象は, 血液透析 (HD) 歴が2年以上の安定期HD患者10人と, 導入期HD患者8人とした.<br>まず, EPO投与前後のRBC数, RET率を経時的に測定した著者の成績とこれまでの諸報告に基づきシュミレーションカーブを作成し, EPO投与4週以降14週までの期間のRBCの増加を予測する式を作成した.<br>この予測式に安定期HD患者6例のEPO投与後4週および8週目のRET数とRBC数を当てはめ, 8週および12週先のRBC数を予測したところ, 実測RBC数と近似した結果が得られ, 予測は可能と思われた, さらに, この予測式により導入期HD患者のEPO投与後のRBC数を算出し, 実測値と比較したが, 実測値がやや高値を示した. また, EPO投与後5週間の平均RBC増加数は, 導入期HD患者で82万個, 安定期HD患者では46万個であり, 導入期のRBC増加は, 安定期の約1.8倍であった.