冷卻過濾技術 Cryofiltration

Cryofiltration 冷卻過濾技術

 

Latest Technical Trend of Cryofiltration

米川 元樹
Yonekawa Motoki特定医療法人北楡会 札幌北楡病院
Sapporo Hokuyu Hospital

川村 明夫
Kawamura Akio特定医療法人北楡会 札幌北楡病院
Sapporo Hokuyu Hospital

Cryofiltration is a double filtration plasmapheresis (DFPP) and, besides the DFPP system, requires the cooling system and the washing-out procedure of the second filter for reuse. We developed the cooling system. At first, we soaked the cooling coil and second filter in ice and water, which was simplest, but it was difficult to control the temperature. The second version of the cooling system was an electric refrigerator, which required more than one-and-a-half hours to get ready. The coolers capacity was 55L. The third version was soaking the coil in propylene glycol, which was the cooling medium. It required one hour to prepare. To make the cooling system smaller, we adopted the Pertier element for cooling. A thin cooling bag was sandwiched between the two cooling plates, which consisted of 13 pieces of Pertier element. This system could attain a constant temperature within 5 min. The washing-out procedure of the second filter was so complicated that we devoloped an automatic washing-out system with computer control. The automatic cryofiltration system, which consists of the cooling plate system and the automatic washing-out system, is useful not only for cryofiltration, but also for DFPP and adsorption apheresis.

Japanese journal of apheresis日本アフェレシス学会雑誌  21(1)  pp.20-27 20020228
Japanese Society for Apheresis

Woman receives ‘incompatible’ kidney
with ground-breaking operation
http://www.timesonline.co.uk/tol/life_and_style/health/article7015508.ece#comment-have-your-say

A British woman has undergone a life-saving kidney transplant after having her blood plasma frozen and filtered to ensure that the organ was not rejected.

Maxine Bath, 41, is the first person in the world to have the groundbreaking operation, which allowed her to receive an “incompatible” donor kidney from her sister despite having dangerously low blood pressure.

Ms Bath, who had been on dialysis for 15 years after kidney failure, waited a decade for a kidney that would not trigger tissue rejection by her body. Doctors feared that she had only months to live after developing blood pressure problems over the past year.

The operation, carried out at University Hospital in Coventry at the end of November, involved the use of a cryofiltration system to remove plasma from the blood and chill it, turning proteins and antibodies into a gel-like substance.

This allowed the antibodies, which can prevent a transplanted organ from being accepted, to be filtered away before the plasma was warmed up and returned to the patient.

Rob Higgins, a renal consultant, told The Times that it was the first time the technique had been used in a tissue incompatible transplant. He added that it had been essential because other antibody-removal procedures would have lowered Ms Bath’s blood pressure even further.

The family of Ms Bath, from Wolverhampton, was tested ten years ago to see if any were suitable donors but none was compatible.

A total of 927 kidney transplants from living donors were carried out in Britain last year — more than one in three of all kidney transplants — but thousands more remain on waiting lists. About a quarter of patients requiring kidney transplants have some antibody against other people’s tissue types.

Among the members of Ms Bath’s close family, it was her younger sister, Michelle Titmus, who was the closest match. Both sisters had five sessions of cryofiltration before Ms Bath was able to receive a kidney from her sister.

Dr Higgins, of University Hospitals Coventry and Warwickshire NHS Trust, said that the technique offered the potential to carry out life-saving operations on many more people who would otherwise be ineligible due to rejection and blood pressure problems. “This is an innovative measure we have implemented at the trust which opens the doors of donation for more kidney patients awaiting transplants,” Dr Higgins said.

“If Maxine had carried on with dialysis her chances were pretty slim.” He added that had she survived further dialysis, she would have gone blind because of her low blood pressure. The number of people with severe kidney disease that require dialysis and transplantation is increasing in all western societies, mostly because of the increase in diabetes and ageing populations. In some cases replacement plasma is used, rather than cryofiltration, but this is not always tolerated and can produce further drops in blood pressure.

Ms Bath said that after completing six months of rehabilitation she had a job as a cleaner lined up. “Although it’s not been long since I had the operation I’m already feeling healthier,” she said.

“I am looking forward to being able to eat food I couldn’t have at all before like nuts and chocolate. I just want to get back to a normal life.”

Mrs Titmus, of Kingstanding, Birmingham, said that it had been heartbreaking to see her sister’s health declining. “knowing there wasn’t anything we could do to help her”.
“It’s been very difficult to see Maxine getting slowly worse over the last few years,” she said. “It may sound silly but it really hits home when I can watch her eat food that could have killed her before, like a jacket potato.”

Mrs Titmus, 40, will return to her job as an office worker after three months of recuperation.

Chris Rudge, the Department of Health’s national clinical director of transplantation, said that the technique was a valuable extension of continuous research into how to transplant kidneys from living donors in circumstances where the recipient had antibodies.

He said that although the number of patients that would benefit would not be large, it was to be welcomed. “Traditionally [antibodies] would mean that a transplant was not possible but there is an increasing range of methods being used to remove the antibodies and so allow the transplantation to go ahead,” he said.

“While the technique may apply to a limited number of patients, to the individual, if it makes the difference between no transplant and a transplant, then it’s hugely important.”

冷卻過濾手術 換腎婦免排斥
http://hk.news.yahoo.com/article/100205/4/gh9c.html

器官移植者要找一個合適不排斥的器官，往往要等上數年，英國一名婦人最近接受全球首宗冷卻過濾系統腎臟移植手術，成功移植一個本來不適合她的腎臟而無排斥現象，不但挽回一命，還可重過正常生活。

41歲婦人巴思（Maxine Bath）因腎衰竭    需要洗腎長達15年，由於久候不到合適腎臟，去年出現血壓問題。醫生表示，若不及時換腎，巴思將活不過數月；就算她靠洗腎暫時活過去，也會因血壓過低而失明。巴思的家人早在10年前已接受過捐贈測試，證實勉強移植必會令巴思產生排斥反應，但在無計可施下，家人最後仍決定由妹妹米歇爾捐贈。

冷卻血漿 濾走排斥抗體

英國考文垂大學醫院去年11月底，為巴思進行一項突破性手術。醫生使用冷卻過濾系統（cryofiltration system ），先抽取巴思血液裏的血漿，用冰水予以冷卻，令血漿裏的蛋白質    和抗體變成啫喱狀物質，再濾走會引發排斥的抗體，然後把血漿弄暖重新輸入患者體內。雖然這過程中，巴思的血壓一度低至危險程度，但她最終移植了腎臟而沒出現無排斥。

負責手術的腎臟顧問醫生希金斯（Rob Higgins）說，這是全球首次在「不相容組織移植上」應用此技術。他表示，此法適用於那些因排斥和血壓有問題的瀕危病人，亦可為等待移植的腎病患者大開方便之門。

換腎後的巴思說﹕「雖然距離接受手術不算久，但我已感到健康許多了。我期待可以吃所有我以前不能吃的食物，我只想重新過正常生活。」