www射-国产免费一级-欧美福利-亚洲成人福利-成人一区在线观看-亚州成人

US EUROPE AFRICA ASIA 中文
World / Kaleidoscope

Altered immune cells rid a girl of her cancer

By Denise Grady (The New York Times) Updated: 2012-12-16 08:17

Altered immune cells rid a girl of her cancer

 

Jeff Swensen for The New York Times 

PHILIPSBURG, Pennsylvania — Last spring Emma Whitehead, then 6, was near death from leukemia. She had relapsed twice after chemotherapy, and doctors had run out of options.

Desperate, her parents sought an experimental treatment at the Children’s Hospital of Philadelphia, one that had never before been tried in a child, or in anyone with the type of leukemia Emma had. It used a disabled form of the virus that causes AIDS to reprogram Emma’s immune system to kill cancer cells.

The treatment nearly killed her. But she emerged from it cancer-free, and about seven months later is still in complete remission. She is the first child and one of the first humans in whom new techniques have achieved a long-sought goal — giving a patient’s immune system the lasting ability to fight cancer.

Emma had been ill with acute lymphoblastic leukemia since 2010, when she was 5, said her parents, Kari and Tom. She is their only child.

She is among just a dozen patients with advanced leukemia to have received the experimental treatment, which was developed at the University of Pennsylvania. Similar approaches are also being tried at other centers, including the National Cancer Institute and Memorial Sloan-Kettering Cancer Center in New York.

"Our goal is to have a cure, but we can’t say that word,” said Dr. Carl June, who leads the research team at the University of Pennsylvania. He hopes the new treatment will eventually replace bone-marrow transplantation, an even more arduous, risky and expensive procedure that is now the last hope when other treatments fail in leukemia and related diseases.

Three adults with chronic leukemia treated at the University of Pennsylvania have also had complete remissions, with no signs of disease; two of them have been well for more than two years, said Dr. David Porter. Four adults improved but did not have full remissions. A child improved and then relapsed. In two adults, the treatment did not work at all.

Despite the mixed results, cancer experts not involved with the research say it has tremendous promise, because even in this early phase of testing it has worked in seemingly hopeless cases.

"I think this is a major breakthrough,” said Dr. Ivan Borrello, a cancer expert and associate professor of medicine at the Johns Hopkins University School of Medicine in Baltimore, Maryland.

Dr. John Wagner, the director of pediatric blood and marrow transplantation at the University of Minnesota, called the Pennsylvania results “phenomenal” and said they were “what we’ve all been working and hoping for but not seeing to this extent.”

A major drug company, Novartis, is betting on the Pennsylvania team and has committed $20 million to building a research center on the university’s campus to bring the treatment to market.

Researchers say reprogramming the patient’s immune system may also eventually be used against tumors like breast and prostate cancer.

To perform the treatment, doctors remove millions of the patient’s T-cells — a type of white blood cell — and, using a disabled form of H.I.V., insert new genes that enable the T-cells to kill cancer cells. The technique employs a disabled form of H.I.V. because it is very good at carrying genetic material into T-cells. The new genes program the T-cells to attack B-cells, a normal part of the immune system that turn malignant in leukemia. The T-cells home in on a protein called CD-19 that is found on the surface of most B-cells, whether they are healthy or malignant.

A sign that the treatment is working is that the patient becomes ill with raging fevers and chills — a reaction that oncologists call “shake and bake,” Dr. June said. Its medical name is cytokine-release syndrome, or cytokine storm, referring to the natural chemicals that pour out of cells in the immune system as they are being activated. The storm can also flood the lungs and cause perilous drops in blood pressure — effects that nearly killed Emma.

In patients with lasting remissions after the treatment, the altered T-cells persist in the bloodstream. Some patients have had the cells for years.

Dr. Michel Sadelain, who conducts similar studies at the Sloan-Kettering Institute, said:

"These T-cells are living drugs. With a pill, you take it, it’s eliminated from your body and you have to take it again.” But T-cells, he said, “could potentially be given only once, maybe only once or twice or three times.”

Researchers are not entirely sure why the treatment works, or why it sometimes fails. It is not clear whether a patient’s body needs the altered T-cells forever. The cells do have a drawback: they destroy healthy B-cells as well as cancerous ones, leaving patients vulnerable to certain types of infections.

So far, her parents say, Emma seems to have taken it all in stride. She went back to school this year with her second-grade classmates.

"It’s time for her to be a kid again and get her childhood back,” Mr. Whitehead said.

Trudeau visits Sina Weibo
May gets little gasp as EU extends deadline for sufficient progress in Brexit talks
Ethiopian FM urges strengthened Ethiopia-China ties
Yemen's ex-president Saleh, relatives killed by Houthis
Most Popular
Hot Topics

...
主站蜘蛛池模板: 亚洲美女黄视频 | 亚洲在线中文字幕 | 成年人视频网站免费 | 99免费精品| 国产极品喷水视频jk制服 | 久久一日本道色综合久久 | 一级片在线免费看 | 国产精品伦理久久久久 | 国产精品视频免费观看调教网 | 亚洲一区二区精品视频 | 97视频精品 | www.日本在线观看 | 一级毛片免费播放 | 久久久精品免费视频 | 国产看片一区二区三区 | 国产午夜精品免费一二区 | 女人把腿劈开让男人桶的网站 | 一级a毛片免费 | 成人97 | 午夜专区 | 女人张开腿让男人 | 97在线视频免费公开观看 | 在线欧美精品一区二区三区 | 欧美一级做一a做片性视频 欧美一级做一级爱a做片性 | 99在线热视频 | 亚洲最大网址 | 国产高清国产专区国产精品 | 久久www免费人成看国产片 | 午夜性激福利免费观看 | 精品免费视频 | 久草在线免费资源 | 精品综合久久久久久88小说 | 亚洲成人免费网址 | 国产成人一级片 | 女人叉开腿让男人捅 | 国产日韩欧美 | 国产亚洲精品看片在线观看 | 日韩欧美在线观看 | 日韩欧一级毛片在线播无遮挡 | 在线成人欧美 | 久艹在线观看 |