主页 > 医学文档 >
【medical-news】特殊免疫系统导致抗肿瘤药物过敏
WASHINGTON (Reuters) - People who live in parts of the U.S. south may have pre-existing immunities that cause a severe allergic reaction to the cancer drug Erbitux, U.S. researchers reported on Thursday.
They found that patients who had sometimes life-threatening reactions had a pre-existing immunity to a sugar compound found in the drug made by ImClone Systems Inc..
The discovery, reported in the New England Journal of Medicine, might help explain why people living in certain regions of the United States are more likely to have the reaction, the researchers said.
And because the drug is so widely used -- it had global sales of $1.1 billion in 2006 for use in treating colon, head and neck cancers -- potential patients should be tested first, the researchers said.
Erbitux, known generically as cetuximab, is a monoclonal antibody, a genetically engineered immune system compound designed to home in specifically on cancer cells.
But some patients have a severe allergic reaction to the drug.
Dr. Thomas Platts-Mills of the University of Virginia and colleagues looked at reports of these cases, which suggest that as many as 22 percent of patients treated with Erbitux in Tennessee and North Carolina reported some kind of reaction, including anaphylaxis, which can rapidly lead to difficulty breathing, shock or fainting.
"It's stunning," Platts-Mills said in a telephone interview.
Even higher rates were reported from parts of Arkansas, Missouri and Virginia. But fewer than 1 percent of patients treated in the Northeast reported any reactions.
CLASSIC IMMUNE RESPONSE
Tests showed a significant number of these patients were having immunoglobulin E or IgE responses -- the classic immune response that causes anaphylactic seizures. Many had them almost instantly after getting the drug, which suggests they had a pre-existing immunity, Platts-Mills said.
His team tested 538 people, including 76 cancer patients who got Erbitux in Tennessee, Arkansas and North Carolina and healthy volunteers from Tennessee, California and Boston.
Of the 76 cancer patients, 25 developed hypersensitivity reactions and 18 had IgE antibodies to the drug.
Of the noncancer patients, antibodies against Erbitux were found in 21 percent of the samples from Nashville, 6 percent of the samples from California and fewer than 1 percent of the samples from Boston.
"We all said why? Why on Earth would they have them?" Platts-Mills said. Possible culprits included ticks, roundworms and certain microbes.
Then Platts-Mills went on a mountain hike. "My feet started itching and I took off my shoes and there were all these baby ticks -- little ones," he said.
He realized these small ticks. known locally as seed ticks, are found only in the south -- the same states where patients were reacting to Erbitux.
"We are making extracts of ticks to test people for IgE antibodies," Platt-Mills said. "We need to know much more about the immune response to ticks in these people."
"These intriguing research findings not only are potentially important to physicians treating certain cancer patients, but also may have broader implications for the use of immunotherapies for other diseases," added Dr. Anthony
Fauci, director of the National Institute of Allergy and Infectious Diseases, which helped pay for the study.
http://www.reuters.com/article/healthNews/idUSN1330426820080313 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 特殊免疫系统导致抗肿瘤药物过敏反应
华盛顿(路透通讯社) - 生活在美国南方部分地区的人们可能已存在引发严重的对肿瘤药物Erbitux过敏反应的预存免疫，美国研究员周四报道。
他们发现，有时经受危及生命的反应的病人具备对在ImClone Systems公司生产的药物中发现的一种糖复合物的预存免疫。
该发现报道在新英格兰医学杂志上，它可以帮助解释，为什么生活在合众国特定的部分地区的人们更易产生上述过敏反应，研究员说。
研究员说，因为该药物应用非常广泛，2006年全球营业额达到11亿美元，用以治疗结肠和头颈部肿瘤，病人首次应用应该测试。
Erbitux归属于cetuximab类，是一种单克隆抗体，一种遗传学上的免疫系统复合物，设计以保护宿主对抗特定的癌细胞。
但一些病人对该药有严重的过敏反应。
弗吉尼亚大学Thomas Platts-Mills博士和同事们注视着这些案例的报道，案例表明，在田纳西州和北卡罗来纳州，多达22%用Erbitux治疗的病人报道了一些反应，包括能迅速引起呼吸困难、休克或晕厥的过敏反应。
“令人震惊”，Platts-Mills在电话采访中说。
阅读本文的人还阅读：
作者:admin@医学,生命科学 2011-01-25 17:14
医学,生命科学网