(BW)(NY-PALL)(PLL)《输血》发表从血液中分离朊病毒的研究报告；研究人员发现颇尔公司的过滤技术能有效分离能引发传染性海绵状脑病的朊病毒

美国商业新闻2005年12月20日纽约州EAST HILLS消息——

一篇在12月期《输血(Transfusion)》中新发表的研究报告显示颇尔公司(Pall Corporation)（纽约证券交易所：PLL）的过滤技术能够从血液中有效分离朊病毒。朊病毒被认为是一种能够引发名为传染性海绵状脑病（Transmissible Spongiform Encephalopathies，TSE）的致命性神经病变疾病的病原体，其中被人们称为“疯牛病”的雅各氏病(vCJD)就是一种传染性海绵状脑病。雅各氏病能够通过输血感染，被感染者在发病前几年都可能毫无症状。

这项研究名为《使用新型去除白血球过滤器从红血球中分离外生（峰值形成阶段）与内生朊病毒》，发表在AABB的官方期刊上（《Transfusion》，2005年；45(12)：1839-1844），显示了过滤技术能够分离感染的绵羊痒病朊病毒。绵羊痒病是一种能够感染绵羊的传染性海绵状脑病。这项研究报告由颇尔医疗公司(Pall Medical)首席科学家兼技术总监Samuel Sowemimo-Coker博士和全球食领先的朊病毒研究中心之一的纽约基础研究院(New York Institute for Basic Research)的科学家们合作编写与完成。

研究报告主要把重心放在三种用来评估颇尔公司的朊病毒分离过滤器性能的方法上面。在研究的外生（峰值形成）阶段，科学家们将被绵羊痒病感染的脑组织添加到人类红细胞当中，然后将其置入朊病毒分离过滤器当中。蛋白质印迹试验结果表明朊病毒低于检测水平。

在另一个外生研究阶段，科学家们稀释被绵羊痒病感染的脑组织，从而来获得不同浓度的有传染性的朊病毒。这些不同浓度的物质被分成了试验组（进行过滤）与对照组（未进行过滤），然后注射进健康仓鼠的大脑当中。（使用仓鼠是一种用来测定朊病毒分离效率的常见方法。）这一阶段研究结果显示朊病毒分离过滤器能够分离3.7 logs（超过99%）的传染性朊病毒。

在研究的内生感染阶段，这也是与血液感染传染性海绵状脑病关系最密切的阶段，所有血液均从出现症状的已经感染了绵羊痒病的仓鼠体内采集。然后使用被指定为测试组（进行过滤）或者对照组（未进行过滤）的红血球血样进行处理，再注射到健康的仓鼠的体内。注射了没有经过过滤的内生传染绵羊痒病红血球的43只动物里有6只动物被感染，而注射了经过过滤的红血球的35只动物则无一传染。

研究人员认为使用这种类型的过滤器能够减少通过血液感染上雅各氏病的风险。Coker博士对此解释说：“通过血液感染雅各氏病是一种严重威胁，而通过过滤来分离朊病毒一种能够降低风险的有现实意义的实用方法。”

全球各地的卫生机构都对雅各氏病感到忧心忡忡。全球已经出现了179起人类病例，其中主要是在英国发现。最近英国之外的病例数量有所增长。美国刚刚报告了第二起雅各氏病例。但是，迄今为止的临床病例的实际数量不能说明雅各氏病所具有的危险，而只有那些成为了传染性朊病毒的载体的病人大量出现才能说明问题。

由于雅各氏病能够保持多年毫无症状，所以不知道多少输血者可能已经被血液感染，因此保护血液供应不受朊病毒感染是最优先的考虑。目前尚没有可靠的测试能够确定血液是否存在雅各氏病毒。在上个月，英国卫生部宣布说它必须跟踪其他50个接受过输血的人，以了解他们是否可能感染了雅各氏病。

许多国家已经采取措施来减少朊病毒的血液传染，比如推迟输血以及减少血液中的白血球等。由于不是所有的朊病毒都与细胞相关，因此减少白血球只能起到部分效果。这项研究中提到的一份报告认为当前的去除白血球过滤器只能减少约42%的传染性海绵状脑病传染性，因此只能作为降低风险的补充战略加以使用。

研究的作者认为：“使用过滤器以及通过有效减少白血球来消除朊病毒，能够提高输血的安全性，减少甚至于是根除通过输血感染雅各氏病以及其他类型的人类朊病毒病症的风险。”

Pall Leukotrap?类同朊病毒分离过滤系统(Pall Leukotrap? Affinity Prion Reduction Filter System)能够减少白血球和传染性的朊病毒。在2005年5月份完成的试验中它能够分离99.9%的朊病毒，目前欧洲各国的输血服务机构正在对其进行评估。它也是首种能够从血液主要成分红血球中分离出传染性朊病毒的技术。颇尔公司将朊病毒分离技术作为公司使命的一部分进行开发，以来保护全球血液供应。

关于颇尔公司(Pall Corporation)

颇尔公司是快速发展的过滤、离析与纯化领域中的全球性领导企业。颇尔公司的业务主要包括两大市场：生命科学与工业市场。公司提供先进的产品以满足生物工程、制药、输血、半导体、水净化、航天以及更多工业市场的需求。公司2005会计年度的总收入为19亿美元。公司总部位于纽约州East Hills，在全球地区设有众多的分支机构。了解关于颇尔公司的更多信息，请访问网站 http://www.pall.com 。

编者注：

——请通过 www.aabb.org 网站的链接下载研究报告摘要。

——复印研究报告，请联系 monette_schnall@pall.com 。

——下载关于朊病毒疾病和Pall Leukotrap类同朊病毒分离过滤系统的图片以及了解更多信息，请访问网页 http://www.pall.com/corporate_38562.asp 。

联系方式：颇尔公司(Pall Corporation) Marcia Katz，516-801-9128 电子邮件：Marcia_Katz@Pall.com

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(BW)(NY-PALL)(PLL) Study on Prion Removal from Blood Published in Transfusion; Research Finds Pall Filtration Technology Effective in Removing Prions that can Cause Transmissible Spongiform Encephalopathies

EAST HILLS, N.Y.--(BUSINESS WIRE)--Dec. 20, 2005--

A newly published study in the December issue of Transfusion shows a Pall Corporation (NYSE: PLL) filtration technology is effective in removing prions from blood. Prions are the agent believed to cause a variety of fatal neurodegenerative diseases called transmissible spongiform encephalopathies (TSEs), including variant Creutzfeldt-Jakob disease (vCJD), the human form of "mad cow" disease. Variant CJD can be transmitted through blood transfusion years before an infected donor shows any symptoms of the disease.

The study, entitled "Removal of exogenous (spiked) and endogenous prion infectivity from red cells with a new prototype of leukoreduction filter," published in the official journal of the AABB (Transfusion 2005; 45 (12): 1839-1844), shows that the filtration technology removes infectious scrapie prions. Scrapie is a TSE disease affecting sheep. The studies were conducted and authored by Samuel Sowemimo-Coker, PhD, Principal Scientist and Technical Director, Pall Medical in collaboration with scientists from the New York Institute for Basic Research, one of the world's leading prion research centers.

The research focused on three approaches to evaluate the performance of the Pall prion reduction filter. In the exogenous (spiking) phase of the study, scrapie-infected brain homogenates were added to human red blood cells and then passed through a prion removal filter. The results showed that prions were removed below the level of detection by the Western blot assay.

In another phase of the exogenous study, scrapie-infected brain homogenates were diluted to obtain a variety of concentrations of infectious prion. These varying concentrations were divided into a test (filtered) group and a control (non-filtered) group and injected into the brains of healthy hamsters. (The hamster is a typical model used to determine prion removal efficiency.) The results of this phase of the study found that the prion reduction filter removed 3.7 logs (over 99.9%) of the infectious prion.

In the endogenous infectivity phase of the study, which is the most relevant to transfusion-transmitted TSEs, whole blood was collected from symptomatic scrapie-infected hamsters. It was processed into red blood cell samples that were designated either as test (filtered) or control (non-filtered) groups and then injected into healthy hamsters. Endogenously scrapie-infected red blood cells that were not filtered transmitted disease to six of the 43 animals, while the filtered red blood cells did not transmit disease to any of 35 animals.

The researchers concluded that the use of this type of filter should reduce the risk of vCJD transmission through blood transfusion. Dr. Coker explains, "Transmission of vCJD by blood transfusion is a serious threat and prion reduction by filtration is a realistic and practical approach to minimize the risk."

Concerns about vCJD are high on the radar screen of health authorities around the globe. There have been 179 human cases identified worldwide, with a majority in the United Kingdom (UK). There has been a recent increase in the number of cases outside the UK. The U.S. just reported its second case of vCJD. However, public health experts contend that the risk of vCJD should not be gauged by the number of actual clinical cases seen to date, but by the prevalence of people who may be carriers of the infectious prions.

Protecting the blood supply from prions is a top priority since vCJD can be asymptomatic for many years and no one knows how many transfusion recipients may be receiving infected blood. There is no reliable test available to determine the presence of vCJD in blood. This past month, the British Department of Health announced that it must track down another 50 people who received a blood transfusion to notify them of potential exposure to vCJD.

Many countries have taken measures to reduce transfusion transmission of prions, including donor deferral and leukocyte (white blood cell) reduction. Leukoreduction alone, however, is known to be only partially effective because not all prions are cell-associated. A report cited in the study suggests that the current generation of leukoreduction filters is effective in removing only 42 percent of the total TSE infectivity suggesting that a complementary strategy to reduce risk is required.

Study authors concluded, "The use of a filter that combines efficient leukoreduction with removal of infectious prions should help improve the safety of the blood supply by reducing, and perhaps even eliminating, the risk of transmission of vCJD and other forms of human prion disease through blood transfusion."

The Pall Leukotrap(R) Affinity Prion Reduction Filter System reduces both leukocytes and infectious prions. It was CE marked with 99.9 percent prion removal efficiency in May 2005 and is currently being evaluated by blood services in several European countries. It is the first technology that reduces infectious prions from red cells, the most widely transfused blood component. Pall developed the prion reduction technology as part of the Company's mission to help safeguard the global blood supply.

About Pall Corporation

Pall Corporation is the global leader in the rapidly growing field of filtration, separations and purification. Pall's business is organized around two broad markets: Life Sciences and Industrial. The Company provides leading-edge products to meet the demanding needs of customers in biotechnology, pharmaceutical, transfusion medicine, semiconductor, water purification, aerospace and broad industrial markets. Total revenues for fiscal 2005 were $1.9 billion. The Company headquarters is in East Hills, New York with extensive operations throughout the world. Visit Pall at http://www.pall.com

Editor's Notes:

-- A study abstract is available online via a link from www.aabb.org.

- Reprints of the study are available by contacting monette_schnall@pall.com

-- Photos and additional information about prion diseases and the Pall Leukotrap Affinity Prion Reduction Filter System can be found on http://www.pall.com/corporate_38562.asp

CONTACT: Pall Corporation Marcia Katz, 516-801-9128 Email: Marcia_Katz@Pall.com