A Gift of Life

Bone marrow transplants can save patients suffering from diseases that were once a death sentence. But a shortage of donors has left thousands waiting for treatment.

生命的礼物

骨髓移植能挽救不治之症患者的生命，但是由于缺乏捐髓者，成千上万的患者只能翘首以待

Every year, 2,000 American lives are saved by the selflessness of others. These are the bone marrow donors who give the gift of life to patients fighting deadly diseases such as leukemia, lymphoma, and aplastic anemia. That's the good news.

每年，骨髓捐赠者的无私奉献使2000名美国人死里逃生，他们将生命的礼物献给了那些与白血病、淋巴瘤和再生障碍性贫血等绝症斗争的患者。这是令人振奋的好消息。

The bad news is that thousands more die each year because not enough people have signed on to the registries that would help the ill find a suitable match for a transplant.

但是坏消息是，由于登记自愿捐赠骨髓的人数还不够多，不能使所有病人都能得到与自己相匹配的骨髓做移植。为此，每年仍有数千位患者在痛苦的等待中死去。

Bone marrow or stem-cell transplants are usually a last resort, intended for those whose illnesses have not responded to traditional treatments such as chemotherapy or radiation. How do they work? We all store a special type of cell in our bone marrow called stem cells. These primitive cells give rise to the three types of blood cells: red, white and platelets. Everyone's stem cells have certain genetic characteristics or markers that make them unique from others. Despite this uniqueness, there are some shared characteristics between people. This is important, because a patient's immune system will reject blood or organs received from someone else if they do not share sufficient similarities.

当传统的治疗如化学疗法或放射疗法不能奏效时，骨髓或干细胞移植通常是这类病人最后的救命之招。它们是如何起作用的呢？人类在自己的骨髓中储存了一种叫作干细胞的特殊类型的细胞。这些原始细胞能衍生出三种不同的血细胞，即红细胞、白细胞和血小板。每个人的干细胞都有特定的遗传特征或标记，使其与众不同。尽管干细胞有这种独特性，但人们的干细胞还是具有一些共性。该共性尤其重要，因为如果不充分具备这种相似性，病人的免疫系统将会排斥移入体内的血液或器官。

Family members, especially siblings, are always the first to be considered as donors, because there's a greater chance that the genetic markers on their cells will have enough in common to prevent rejection after trans? plantation. In many cases, however, a familial match can't be found and then the search begins for an unrelat? bed donor. These donors typi? cally come from a pool of people who have already signed up on a donor registry in the event that their cells match a needy recipient.

为防止出现移植后的排异现象，家庭成员，特别是兄弟姐妹，是骨髓移植的首选捐赠者，因为他们细胞中的遗传标记相同的概率较高。然而，在多数情况下，在家庭成员中很难找到匹配的骨髓，这时只有寻找与患者无亲缘关系的捐赠者，这些捐髓者通常来自于骨髓库，该库由签约自愿者组成，他们随时准备捐髓给与自己细胞相配的患者。

Once the lab has verified a match between donor and re?鄄cipient, the next phase starts. The patient is given radiation or chemotherapy to kill the unhealthy cells. Healthy cells are harvested from the donor - either extracted from the pelvic bones or taken from the arm in a way that is similar to having blood drawn - and prepared in a laboratory. Once they're ready, they're given to the patient through a vein - the same way as one would receive a blood transfusion. Once these transplanted donor cells get settled within the patient's bone marrow, they make the healthy red blood cells, white blood cells and platelets necessary to support life.

捐赠者与受赠患者的骨髓经鉴定相匹配时，就进行下一步，即通过放疗或化疗杀死病人的病变细胞，再用类似于抽血的方法从捐赠者骨盆中或手臂上提取健康的细胞，送到实验室培养，然后再像输血一样，通过静脉注入病人体内。这些被移入的细胞一旦进入患者的骨髓被吸收后，就可制造出生命必需的健康的红细胞、白细胞和血小板。

One of the major problems currently faced by transplant centers is that while bone-marrow transplants can cure more than 70 different diseases, there aren't enough donors on the registry to treat the more than 3,000 patients awaiting transplants. The National Marrow Donor Program, the largest registry in the country, has approximately 4.8 million adult volunteer donors, but that isn't nearly enough for the thousands who need transplants.

尽管骨髓移植能治疗70多种疾病，但许多移植中心面临的主要问题之一是相对于3000多位等待移植的患者，却没有足够的注册捐赠者。美国最大的骨髓捐赠组织---全美骨髓捐赠者计划---已登记在册了近480万名成人志愿捐髓者，但这仍不能满足数千名需要移植的病人。

Why isn't a pool of more than 4 million donors isn't enough to cover 3,000 needy patients? Here's the reason: in the vast majority of cases, finding a suitable match isn't easy. Because we are unique individuals with a variety of ancestral backgrounds and integration patterns, finding someone similar to us is a major task. In the end, it comes down to a numbers game-the more potential donors listed on the registry, the greater a chance of finding a match, especially for those with unusual genetic characteristics.

为什么四百多万的捐髓者还不能满足3000位病人的需要？这是因为在大多数情况下，要找到适合自己的骨髓是十分不易的。因为我们每个人都具有不同的遗传背景和综合类型，找到与自己相似的人真是大海捞针。最终，骨髓捐赠便成了数字游戏，登记在册的捐赠者越多，发现匹配者的可能性就越大，对那些有特殊遗传特征的病人来说尤其如此。