干细胞疗法可能终结第一型糖尿病

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语言: 中文  
　　April 10, 2007 -- 在移植完自体的血液干细胞后，15位第一型糖尿病中，有14位维持1至36个月的不等时间，不需要施打胰岛素，状况好的甚至还持续下去。

　　第一型糖尿病为人体无法制造所需的胰岛素，因此治疗方法就是施打胰岛素；在进行完移植后，研究中大部分的患者变得不需要再施打胰岛素；这是该疗法初次应用在第一型糖尿病，然而，它却有益于合并其它自体免疫疾病的患者，初期的成功是令人振奋的，但还不能算是「治癒」。

　　干细胞疗法的有效作用方式、或是它到底有没有效，目前尚未完全清楚，同时患者不需使用胰岛素的时间能维持多久，也完全没有相关资料显示；巴西Sao Paulo大学的研究员Julio C. Voltarelli医学博士及研究同仁总结指出，从早期发病的少数患者身上，得到令人振奋的研究结果。

　　巴西研究团队预先通知将需要对试验患者进行更长期的追踪、更进一步的生物实验，以及最后的临床试验，以确认该疗法有效；巴西的研究报告发表于4月11日的《美国医学协会期刊》中。

　　【早期结果 极大成果】
　　第一型糖尿病中，失控的免疫细胞攻击胰脏中制造胰岛素的β细胞，这代表第一型糖尿病患无法自行产生体内所需的胰岛素，而需要施打胰岛素补充剂；此疗法的目标是除法这些失控的「坏」免疫细胞，用「还没学坏」的免疫细胞替代，如此将能不让β细胞再受损，并回复妥当的免疫功能。

　　该疗法称为自体骨髓造血干细胞移植（autologous nonmyeloablative hematopoietic stem cell transplantation），疗程有4个步骤：
1. 第一型糖尿病确诊后（趁著患者仍有大量的β细胞留存），立即给予病患能**血液干细胞产生的药。
2. 血液干细胞从病患的体内移出并冷冻，以供未来使用。
3. 病患被投药及施打抗体，以清除免疫细胞，并保持其它血液细胞的完好。
4. 先前冷冻的血液干细胞经处理，再灌输进入病患体内。

　　自体骨髓造血干细胞移植疗法对第一位患者并无效，可能是因为他在开始进行治疗时，体内的β细胞数量过少；不过，接下来的14位经过仔细筛选过的患者，状况则好得很多；这14名患者全都在第一型糖尿病确诊后，立即接受治疗，后来全都不再需要施打胰岛素补充剂，并持续1至35个月。

　　与该研究共同发表的一篇评论中，迈阿密大学糖尿病研究员Jay S. Skyler医师提出「不切实际的希望，是建立在研究结果的初步本质之上」的警告。

　　Skyler医师警告，仍需要再进行许多的研究，理由是：
* 该研究并未安非控制（对照）组，这将不可能知道，若相似病况的患者未接受治疗，会发生什么状况—有一个很重要的因子，确诊后不久，许多第一型糖尿病患者会进入症状缓解的「蜜月」期。
* 还太早去论断该疗法是多有效，或接受治疗患者最后将是否会比未治疗的患者表现得更好。
* 并不完全清楚，疗法有效是因为它停止β细胞的破坏，或是否它允许了β细胞的再生。

　　Skyler医师并提到，此疗法并非目前唯一研发来针对第一型糖尿病的细胞疗法，其它的疗法，包括调节细胞（ regulatory cell）的灌输，以重新调整自体免疫细胞、脐带细胞、胚胎或成人干细胞，以及骨髓移植。

　　Skyler医师指出，当这些更深入的研究确认并建立在Voltarelli博士及同仁研究的基础上，或许届时才真正到了开始逆转和预防第一型糖尿病的时机。
  
Stem Cells May Stop Type 1 Diabetes
语言:  English  
After transplants of their own blood stem cells, 14 of 15 type 1 diabetes patients are insulin free for one to 36 months -- and counting.


Stem Cells May Stop Type 1 Diabetes
Blood Stem Cell Transplant Leaves Diabetes Patients Insulin Free -- So Far

April 10, 2007 -- After transplants of their own blood stem cells, 14 of 15 type 1 diabetes patients are insulin free for one to 36 months -- and counting.

In type 1 diabetes, the body can't make the insulin it needs, and so insulin injections are necessary for treatment. After their transplants, most of the patients in the study became free from insulin injections.

It's the first time the treatment has been used in type 1 diabetes, although it's helped patients with other autoimmune diseases. The early success is encouraging -- but nobody is using the word "cure."

It's not yet clear exactly how the stem cell treatment works, or even whether it truly works at all. And it's far from clear how long treated patients will remain insulin free.

"Very encouraging results were obtained in a small number of patients with early onset disease," conclude researchers J缴lio C. Voltarelli, MD, PhD, of the University of S琼o Paulo, Brazil, and colleagues.

The researchers warn that longer follow-up of trial patients, further biological studies, and, finally, a clinical trial will be needed to confirm that the treatment works. Their report appears in the April 11 issue of TheJournal of the American Medical Association.


Early Results, Enormous Promise


In type 1 diabetes, haywire immune cells attack the insulin-making beta cells in the pancreas. This means people with type 1 diabetes can't make the insulin they need and require the use of supplemental insulin. The goal of the treatment is to get rid of these bad immune cells and to replace them with immature cells that have not yet learned bad habits -- thus stopping beta-cell damage and restoring proper immune function.

The treatment is called autologous nonmyeloablative hematopoietic stem cell transplantation. It's a four-step process:

Soon after diagnosis of type 1 diabetes -- while a person still has plenty of beta cells left -- the patient is given drugs that stimulate production of blood stem cells.
The blood stem cells are removed from the patient's body and frozen for later use.
The patient is given drugs and antibodies that kill off immune cells, leaving other blood cells intact.
The blood stem cells are reinfused into the patient.
The treatment didn't work in the first patient, probably because he had too few beta cells when he started.

But the next 14 carefully selected patients did much better. All were treated soon after diagnosis of type 1 diabetes. All eventually stopped needing insulin -- for one to 35 months.

In an editorial accompanying the study, University of Miami diabetes researcher Jay S. Skyler, MD, warns against "false hope based on the preliminary nature of the study results."

Skyler warns that much work remains to be done:

The study did not include a control group. This makes it impossible to know what would have happened if similar patients had received no treatment -- an important factor, given that soon after diagnosis, many type 1 diabetes patients enter a "honeymoon" period of remission.
It's simply too soon to know how well the treatment worked, or whether patients eventually will do better than untreated patients.
It's not at all clear whether the treatment works because it stops beta cell destruction or whether it allows beta cells to regenerate.
Skyler also notes that this treatment isn't the only cellular treatment now being developed for type 1 diabetes. Other treatments include infusions of regulatory cells to reorient autoimmune cells, umbilical cord cells, embryonic or ** stem cells, and bone marrow transplant.

"As these further studies confirm and build on the results of Voltarelli and colleagues -- the time may indeed be coming for starting to reverse and prevent type 1 diabetes mellitus," Skyler suggests.