埃博拉幸存者的血液不能够有效救助感染者

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研究证实，使用埃博拉幸存者血液治疗埃博拉病毒感染者似乎并不起作用。现在是时候放弃这种治疗方法了。

由于没有破坏性疾病许可的治疗，医生们有时会用幸存者的血液去治疗病人，希望其血液中的抗体能够帮助患者战胜病毒。这种方法在过去似乎帮助了一些患者，但是并没有明确的证据表明这种方法有效。当2014年埃博拉病毒疫情在西非大爆发时，科学家决定在几内亚展开这种经验性医疗方式的可行性和有效性。

在首都科纳克里的一间诊所，科学家发现使用埃博拉幸存者血液治疗的84名埃博拉病毒感染者与约400名患者相比，其在五个月内的生存期没有区别。这一研究结果发表在1月7日的新英格兰医学杂志上。

本文的第一作者Johan Van Griensven说道，“我们本希望看到更多戏剧性的结果，但是在几内亚的这项研究表明这种利用血液的治疗方法并不起作用”。

他强调，刚从埃博拉病毒感染中恢复过来的患者，其体内抗体水平往往较低。所以应该利用长期幸存者的血液进行下一步的试验。

埃博拉病毒疫情爆发以来已经造成西非超过11000人死亡。几内亚上个月宣布埃博拉疫情结束。有人说，这次试验的失败足以说服科学家放弃这一治疗战略。

德克萨斯大学医疗部的专家Thomas Geisbert说道，“从结果来看，这种治疗方法不值得追求”。

英国病毒学家Ben Neuman说道，“利用埃博拉痊愈者的血液来治疗患者的生命是一个好的想法，但是要对这种方法进行必要的测试”。

目前可以明确的是这种治疗埃博拉感染的方法不可行。以后应该进行更多有前途的药物和疫苗的测试。

来源：来宝网

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Evaluation of Convalescent Plasma for Ebola Virus Disease in Guinea

Johan van Griensven, M.D., Ph.D., Tansy Edwards, M.Sc., Xavier de Lamballerie, M.D., Ph.D., Malcolm G. Semple, M.D., Ph.D., Pierre Gallian, Ph.D., Sylvain Baize, Ph.D., Peter W. Horby, M.D., Ph.D., Hervé Raoul, Ph.D., N’Faly Magassouba, Ph.D., Annick Antierens, M.D., Carolyn Lomas, M.D., Ousmane Faye, Ph.D., Amadou A. Sall, Ph.D., Katrien Fransen, M.Sc., Jozefien Buyze, Ph.D., Raffaella Ravinetto, Pharm.D., Pierre Tiberghien, M.D., Ph.D., Yves Claeys, M.Sc., Maaike De Crop, M.Sc., Lutgarde Lynen, M.D., Ph.D., Elhadj Ibrahima Bah, M.D., Peter G. Smith, D.Sc., Alexandre Delamou, M.D., Anja De Weggheleire, M.D., and Nyankoye Haba, M.Sc. for the Ebola-Tx Consortium

BACKGROUND
In the wake of the recent outbreak of Ebola virus disease (EVD) in several African countries, the World Health Organization prioritized the evaluation of treatment with convalescent plasma derived from patients who have recovered from the disease. We evaluated the safety and efficacy of convalescent plasma for the treatment of EVD in Guinea.

METHODS
In this nonrandomized, comparative study, 99 patients of various ages (including pregnant women) with confirmed EVD received two consecutive transfusions of 200 to 250 ml of ABO-compatible convalescent plasma, with each unit of plasma obtained from a separate convalescent donor. The transfusions were initiated on the day of diagnosis or up to 2 days later. The level of neutralizing antibodies against Ebola virus in the plasma was unknown at the time of administration. The control group was 418 patients who had been treated at the same center during the previous 5 months. The primary outcome was the risk of death during the period from 3 to 16 days after diagnosis with adjustments for age and the baseline cycle-threshold value on polymerase-chain-reaction assay; patients who had died before day 3 were excluded. The clinically important difference was defined as an absolute reduction in mortality of 20 percentage points in the convalescent-plasma group as compared with the control group.

RESULTS
A total of 84 patients who were treated with plasma were included in the primary analysis. At baseline, the convalescent-plasma group had slightly higher cycle-threshold values and a shorter duration of symptoms than did the control group, along with a higher frequency of eye redness and difficulty in swallowing. From day 3 to day 16 after diagnosis, the risk of death was 31% in the convalescent-plasma group and 38% in the control group (risk difference, −7 percentage points; 95% confidence interval [CI], −18 to 4). The difference was reduced after adjustment for age and cycle-threshold value (adjusted risk difference, −3 percentage points; 95% CI, −13 to 8). No serious adverse reactions associated with the use of convalescent plasma were observed.

CONCLUSIONS
The transfusion of up to 500 ml of convalescent plasma with unknown levels of neutralizing antibodies in 84 patients with confirmed EVD was not associated with a significant improvement in survival. (Funded by the European Union’s Horizon 2020 Research and Innovation Program and others; ClinicalTrials.gov number, NCT02342171.)

http://www.nejm.org/doi/full/10.1056/NEJMoa1511812