英衆多父母爲孩子儲存臍帶血

Future proofed: Alex Silver and daughter Scarlett. She has banked her daughter's umbilical cord blood in case of any future medical emergencies

Today there are about ten businesses in the UK offering to freeze and store cord bloodand industry insiders estimate that up to 100,000 parents have chosen to do so in the UK. The global stem-cell market is forecast to trebleto a staggering￡40 billion by 2015.

Cord blood contains embryonicstem cells. They can be made into more specialised cells and can reproduce copies of themselves almost indefinitely. There is currently research into a host ofapplications – from growing new organs to curing paraplegia. In theory, stem cells treat disease by replacing damaged or diseased cells. They are used in bone-marrow transplants to treat leukaemia– but in these cases, donor blood taken in the usual way is used to harvest the stem cells.

To bank cord stem cells, the cord blood is extracted minutes after the birth of the baby and rushed by courierto be processed. Any cells that could be of future value are frozen at minus 180C and can then be stored for 25 years.

There are no published examples of a child’s own cord blood being used to cure them of leukaemia – one of the most common childhood diseases mentioned by the banks in their sales pitches. There are two cases of successful sibling transplants for children with the hereditary condition thalassemia, where the body makes an abnormal form of haemoglobin– the protein in red blood cells that carries oxygen. These were carried out in Singapore and Germany.

Lavish promises of future treatments tend to be based on preliminary clinical trials – and should a child fall ill today, in many cases the technology doesn’t exist to actually use the harvested stem cells. In fact, some experts believe that reintroducing banked cord blood into a child could increase the chance of relapse– as disease-causing cells that existed from birth would be stored alongside useful stem cells.

‘Parents are worried that by not storing cord blood, they aren’t giving their child the best possible chance for future health,’ says leading consultant gynaecologistand obstetricianMr Dickinson Cowan, who admits that when he first came across private banking, he thought it was a good idea. ‘I’d never recommend it now,’ he says.現在英國約有十家公司提供冷凍儲存臍帶血的服務，業內人士估計，英國有10萬父母選擇爲孩子保存臍帶血。據預測，全球幹細胞市場份額在2015年將多達400億英鎊，增至原來的三倍。

臍帶血含有胎兒的幹細胞。它們可以發展成更專門的細胞，而且幾乎能無限地被複制。目前有針對一系列應用的研究——從生成新器官到治療截癱。理論上，幹細胞可通過替換受損或病變的細胞來治療疾病。它們被用在骨髓移植中，用來治療白血病。不過，在這些情況下，幹細胞從捐贈者按正常方式抽取的血液中獲得。

爲了儲存臍帶血幹細胞，臍帶血在嬰兒出生後數分鐘內被抽取，並迅速由專遞員送去處理。任何在未來會有使用價值的細胞都要在零下180攝氏度的環境中儲存，這樣才能保存25年。

當前公開報道中還沒有能夠用孩子自己的臍帶血治療白血病的例子。白血病是臍帶血庫在他們的廣告宣傳中提到的最常見的兒童疾病。曾經有兩例患遺傳的地中海貧血病的小孩被成功移植了兄弟/姐妹的幹細胞。地中海貧血病患者的身體會產生異常的血紅蛋白（血紅蛋白是紅細胞中運載氧氣的蛋白質）。這兩次成功移植分別發生在新加坡和德國。

臍帶血給人帶來的在未來治療中的巨大希望一般是基於初步的臨牀試驗，但假如現在某個小孩生病了，大多情況下並不存在可以真正運用儲存的幹細胞的技術。事實上，一些專家認爲，將儲存的臍帶血重新輸入孩子的體內會增加舊病復發的機率，因爲從出生時就存在的致病細胞將和有用的幹細胞一起保存在臍帶血內。

首席顧問醫生、婦產科專家迪金森 考恩先生說：“父母們擔心如果不儲存臍帶血，他們就沒有爲孩子的未來健康提供最好的機會。”考恩承認，當他最開始聽說自體庫時，他認爲這是個好主意。但他說：“我現在絕對不會建議儲存臍帶血。”