[双语新闻]美国医生找到让骨髓移植更安全有效的新方法 Doctors Make Safer Bone

摘要：

美国医生似乎已经找到了一种让骨髓移植更为安全有效的新方法，以治疗诸如白血病之类的血液癌症。值得一提的是，这种新方法还适用于50岁以上的年纪较大的患者。

Doctors seem to have found a way to make bone marrow transplants safer and more effective against blood cancers like leukemia, an achievement that offers new hope for people over 50 in particular.

据美联社9月28日报道，美国斯坦福大学的医生们找到的这种新方法使那些能够显著提高儿童和年轻人癌症幸存率的骨髓移植手术同样也适用于年纪较大的患者。同时，这种新方法还让这一领域离它追求的最高目标更近了一步——训练接受移植手术的患者的身体去接受来自其他人的器官，并且让患者与移植器官生活得更为“融洽”，不会对抗排斥的药物产生过分的依赖性。

以前，科学家们已经应用这一方法在老鼠身上成功地进行了骨髓移植；而现在，斯坦福的医生们又把这一方法推广到了癌症患者身上。他们的研究发表在9月29日出版的英国《新英格兰医学杂志》上。他们的这项研究受到了美国国家健康研究所的资助。

有关医学专家表示，尽管这项研究规模不大，同时只处于初步阶段，但是它的前景看好。对此，世界血液和骨髓移植研究中心的科学主管玛丽·霍罗威茨医生说：“如果这个方法起作用，我们将能够对更多的患者进行移植手术。”

报道说，从理想上来说，一位白血病或淋巴瘤患者在从捐赠人那里接受健康的骨髓或血液干细胞前，应该接受放射疗法或大剂量的化学疗法以摧毁癌变骨髓。然而，很多患者，特别是那些年龄在50岁以上的患者会在新骨髓被接受及开始生长前因感染而死亡。

为了避免这个问题，医生们通常只会毁坏掉患者一部分的原始骨髓。然而这种作法也带来了另外一些问题：一些癌变的血细胞被保存了下来，而新骨髓常常会对旧骨髓进行攻击——这被称之为移植物抗宿主病（graft-versus-host disease），通常都是致命的问题。

斯坦福大学的研究人员发现了一种方法，可以让接受移植的患者适应新的骨髓，并使他们的部分免疫系统活性减弱。具体方法是，进行两个星期的低剂量放射治疗，同时结合短程服用免疫抑制药物。

报道说，在37名接受实验治疗的病人当中，只有2人患上了移植物抗宿主病。而平常，超过一半的病人都会出现这种病症。平均在1年以后，这37人之中有27人仍然幸存，其中24人的病情完全好转——这一结果也比通常的治疗方法效果好得多；这些病人的平均年龄为52岁。此项研究的主要负责人塞缪尔·斯特罗贝尔医生对此表示：“这种方法能在治愈肿瘤的同时，又没有出现可怕副作用的高危险性。”

报道说，尽管这些成果还需要进行更多的研究来证实，接受实验治疗的患者也要被长期跟踪，以观察他们是否能一直保持无癌症状态，但是这一方法的确让人“印象深刻”、“在这一领域开创了一个新的纪元”。

（国际在线独家资讯王高山）

本稿件为国际在线专稿，媒体转载请注明稿件来源和译者姓名。

Doctors seem to have found a way to make bone marrow transplants safer and more effective against blood cancers like leukemia, an achievement that offers new hope for people over 50 in particular.

The advance by Stanford University doctors could make such transplants, which have dramatically improved cancer survival among children and young adults, more widely available to older people who typically don fare as well.

It also brings the field closer to its Holy Grail — training a recipients body to accept tissue from another person and live a "blended" life without heavy reliance on anti-rejection drugs.

Scientists already had achieved this in mice; Stanford researchers now have extended it to people. Their study is published in Thursdays New England Journal of Medicine and was funded by the National Institutes of Health.

Specialists said the study was small and preliminary, but very promising.

"If it works, we would be able to do transplants in a lot more people," said Dr. Mary Horowitz, scientific director of the Center for International Blood and Marrow Transplant Research, based at the Medical College of Wisconsin, which had no role in the research.

Ideally, a leukemia or lymphoma patient would be given radiation or high doses of chemotherapy to destroy the cancerous bone marrow before receiving healthy marrow or blood stem cells from a donor. However, many patients, especially those over 50, die of infections they are unable to fight off before the new marrow takes hold and grows.

To avoid this problem, doctors usually destroy only part of the patients original marrow. That brings other dilemmas: some cancerous blood cells remain, and the new marrow frequently attacks the old — an often-fatal problem called graft-versus-host disease.

Stanford researchers developed a way to condition the recipient to accept the new marrow and to inactivate the parts of the patients immune system that would attack it. They used a combination of low-dose radiation over two weeks and short courses of immune-suppressing drugs.

Only 2 of the 37 patients given the experimental treatment developed severe graft-versus-host disease. Ordinarily, more than half of them would have.

An average of one year later, 27 of the 37 were still alive, and cancer was in complete remission in 24 of them — better results than usual. The average age of the patients was 52.

"It can achieve the cure of the tumor without the high likelihood that you will come down with the dreaded side effect," said the lead researcher, Dr. Samuel Strober.

The results need to be repeated in larger studies, but are "impressive" and "open a new era in the field," Dr. Gerard Socie, a transplant expert from several universities in Paris, wrote in an accompanying editorial.

Patients also need to be followed for longer than a year to see if they remain cancer-free, Horowitz said.

Bone marrow and blood cell transplants are one reason the death rate from childhood cancers has dropped roughly 50 percent since the 1970s. Leukemia is the most common cancer that children face, but it is diagnosed 10 times more often in older adults — the very group for whom transplants have been most dangerous.

With the new treatment, "the side effects are being markedly reduced, which is good news for elderly patients with leukemia and lymphoma," Strober said.

The approach also might help people receiving organ transplants if they are "conditioned" with marrow or blood cells from the donor before receiving a kidney or other organ, Strober said.

[双语新闻]美国医生找到让骨髓移植更安全有效的新方法 Doctors Make Safer Bone Marrow Transplants