利用過濾法進行白血球濃縮單採原型之開發

Abstract

全血進行血液單採分離後取得之血品稱為成分血，分離後之成分血可以對應至不同需求應用在醫療中，減少血液資源的浪費。白血球濃厚液是其中一種血品，可以應用於免疫治療，目前其主要製備方法為離心法。 使用離心法製備白血球濃厚液時，因白血球數量遠少於紅血球，離心分層後依然不易取出白血球，因此本論文將建立以薄膜橫流過濾(cross-flow filtration)與血液透析過濾法(Hemodiafiltration)為基礎之血球過濾模型，將全血分離，進行白血球的濃縮。使用與人血相近之豬血進行研究以建立過濾器之白血球濃縮模型；其中豬血的紅血球大小約為5.8μm，白血球大小約為8~16μm，考慮血球為彈性體，選用平均孔徑4.5μm之PET濾膜；比照透析器之模型，利用兩流向相反之血液流與生理食鹽水流，使其在過濾膜兩側產生體積流量差，進行過濾作用。由於PET薄膜的孔徑的篩選性，直徑較小之紅血球，將穿過薄膜而減少數量，而直徑較大之白血球則因無法穿過薄膜，而讓cross-flow的橫流帶回血液中或吸附在薄膜上。持續這個過程，全血就會逐漸濃縮成白血球濃縮血品。最後在利用薄膜逆洗(backwash filtration)的方法，將吸附在薄膜上之血球回沖回血液中，提高血球之回收率。 本研究建立之過濾模型，藉由透過控制蠕動幫浦之流量，讓薄膜穿越量為(0.4、0.6 ml/min)的情形下，進行1小時之過濾，使紅、白血球之回收率差異到達5.7%，產生白血球濃縮之效果，並透過薄膜逆洗的過程，將吸附在薄膜之血球回沖，使白血球之回收率達79.3%。

Whole blood can be separated by using apheresis methods into blood products for different indications. One of the blood products is white blood cell concentrates (WBC concentrates), which are important in immunotherapy. The conventional approach is to use syringes to obtain the WBC concentrates from the buffy coat - the thin layer between plasma and red blood cells (RBCs) after the centrifugation methods. It is a manual process and difficult to the WBC concentrates with high purity. To automate the WBC concentrate preparation procedures, a prototype system, which employs dialyzer and membrane filtration to directly separate the blood cells based on the size, is proposed. A filtration membrane with the pore size at 4.5 μm in average is used. Porcine blood, whose RBCs are 5.8 μm and white blood cells (WBCs) are 8~12 μm in diameter, are tested. The flow rates of the blood and dialysate are controlled for a systematic study to evaluate the perforamnce of the prototype. The system with the permeate flux at 0.4 and 0.6 ml/min is found to be able to concentrate the WBCs. In addition, to enhance the performance since the membrane is found to trap blood cells during the filtration, backflow filtration is tested. The permeat flux is controlled to have a counter current flux to backwash the membrane. The recovery rate of the WBC is enahnce to 79.3%, with a reverse permeate flow rate at 2.5 ml/min. Keywords: WBC concentration, leukapheresis, blood separation, membrane filtration, cross-flow filtration.