2011年3月11日，日本發生規模9.0的強震，並伴隨海嘯的發生，大地震造成位在福島核電廠的發電機產生輻射外線。15日，日本官方證實，搶救福島核電廠危機的工作人員，所暴露到的輻射量已從每年的100豪西氟(mSv/y)上升至每年的250豪西氟(mSv/y)。

輻射線最易破壞人體的腸胃道與血液系統，局部的破壞也會擴大到全身，內部也會延伸到外部。根據研究，人體暴露於2戈雷(Gy)以上的輻射量，骨髓會受到破壞，引響造血功能，此時可以注射造血生長因子以補救，如果暴露於5戈雷(Gy)以上的輻射量，就需要注射造血幹細胞。(1Gy=0.8Sv)

1986年車諾比事件，有9位暴露於高劑量輻射能的病患，接受異體骨髓的移植；1999年日本茨城縣東海村的核能燃料處理場事件，2位犧牲者接受異體幹細胞的移植。然而異體移植淺在許多風險：1.等待配對的時間。2.植入失敗。3.移植物抗宿主疾病(GVHD)等，因此專家建議能多利用自體的幹細胞移植。

日本衛生機關25日提出，收集並保存福島發電廠勇士的自體周邊血幹細胞(peripheral-blood stem cells;PBSCs)的計畫。自體移植的治療效果更好，是因為：1.不會產生GVHD：輻射暴露的病人會有更強烈的排斥反應。2.移植後不需施打免疫抑制劑：避免病人更易受到微生物的感染。3.加快血球生成：與施打生長因子和骨髓移植相比，周邊血移幹細胞更能促進血球的生成。4.方便儲存：與骨髓幹細胞相比，周邊血幹細胞可事先儲存，以提供移植時使用。5.移植後安全性佳：經證實，利用周邊血幹細胞治療惡性血液疾病，不論是短期或長期都具有安全性。

目前已有107個移植團隊願意幫忙採集福島勇士的周邊血，不只日本，歐洲的血液與骨髓移植組織也認同並重視這項計畫，已有50個醫療院所願意加入收集與儲存周邊血幹細胞的工作團隊。

再生醫學領域正在發展，幹細胞的臨床運用越來越廣，幹細胞是真正能達到治療疾病、器官修補、細胞重建的醫療資源。除了周邊血幹細胞，配對成功的臍帶血幹細胞更是治療的最佳來源，因為臍帶血幹細胞更原始，分化與複製能力更強，能提供福島勇士另個治療的選擇。

Stem Cell Collection, Storage Proposed for Japanese Nuclear Workers

 

April 18, 2011 — Japanese health organizations are proposing the collection and storage of nuclear workers' autologous peripheral-blood stem cells (PBSCs) at the Fukushima Daiichi nuclear power plant, despite opposition from some industry groups.

The 9.0-magnitude earthquake and subsequent tsunami that occurred on March 11, 2011, swamped emergency generators at the Fukushima Daiichi nuclear power plant and disabled the cooling systems, according to a letter published online April 15 in The Lancet.

According to the authors, some of the advantages of autologous PBSC transplantation include the fact that it does not result in graft-vs-host disease, which exacerbates radiation-induced gut injury. In addition, autologous PBSC transplantation does not require immunosuppressants and can induce more rapid hemopoietic recovery than other approaches. Furthermore, storage is simple, and the procedure is safe and well validated.

"Long-term autologous PBSC banking might also have a therapeutic role for possible leukaemia in future, because radiation is a well known carcinogen in the long term," they add.

However, several groups have stated their objections to this plan. "The Nuclear Safety Commission of Japan, an advisory panel made up of non-government experts, reportedly stated that there is no need to collect and store autologous PBSCs," the authors note.

Those opposed cite reasons such as the physical and psychological burden and the fact that a consensus among authorities and the public is lacking. However, the authors point out that "the officials and authorities related to the industry seem to be reluctant to admit the seriousness of the problem to protect the industry's reputation as much as possible."

Banking of autologous PBSCs will become increasingly important, the authors conclude. "Toranomon Hospital in Tokyo is ready to harvest and bank autologous PBSCs for the nuclear workers upon request."

Lancet. Published online April 15, 2011. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2811%2960519-9/fulltext