美国国家公共电台 NPR--More pollen, more allergies: Personalized exposure therapy treats symptoms

More pollen¹, more allergies²: Personalized exposure therapy treats symptoms

Transcript³

If you're sniffling and sneezing you're not alone. Mild winters, like the one the eastern U.S. has had, can bring longer allergy⁴ seasons, as warmer temperatures prompt some plants to produce more pollen.

For the millions of Americans who battle allergies, taking over the counter antihistamines⁵, often combined with a steroid nasal spray, is enough to tamp⁶ down symptoms temporarily. But Abigail Bortnick, 41, wanted a way to prevent allergic⁷ reactions over the long term.

"I had really bad seasonal⁸ allergies," Bortnick says. Tests showed she was allergic to grasses and weeds, and she recalls feeling lousy when pollen counts rose. "I would have a runny nose, itchy eyes, the whole deal," says Bortnick, who lives in the Washington, D.C. area.

Allergy shots were one option, but with young children and a busy career, it wasn't convenient to drive to the doctor's office each week to get a shot. So, her allergist offered her an alternative, called sublingual immunotherapy, known as SLIT⁹, a form of exposure therapy. She was given liquid drops she can administer herself. "I liked the idea of not having to go in for shots and being able to do it at home," Bortnick says.

Five drops, personalized serum¹⁰

The serum comes in a small bottle with a pump on top. Once each day she puts five drops under her tongue. "It makes it easy," Bortnick says. She can't eat or drink for 30 minutes, so she aims to take them at the same time every day, so they don't interfere¹¹ with meals.

She started the allergy drops a few years ago and has seen a significant improvement. "I've absolutely noticed that my allergies are much better," Bortnick says. She's also noticed she has more energy, perhaps because she's sleeping better due to less congestion¹² and inflammation. When she starts a new vial she sometimes gets a "slight bit of itchiness" in her mouth, but that subsides¹³ quickly. And at the height of grass pollen season she still takes Claritin, but her symptoms are much less severe.

Both allergy shots and SLIT are forms of allergy immunotherapy. Patients are exposed to very small amounts of the specific things they're allergic to with the goal of training the immune system to tolerate them, gradually, over time. Doctors make SLIT allergy drops the same way they make allergy shots, mixing extracts of allergens. For each patient, the serum is personally tailored to include the specific mix of irritants that trigger their allergies.

"Part of the beauty of the therapy is its convenience," says Dr. Rachel Schreiber, an allergist in Rockville, Maryland who treats Bortnick. Schreiber says patients typically stay on SLIT for several years. "We reevaluate yearly to determine whether we should continue the therapy," she explains. Sometimes patients stop too early and symptoms can recur¹⁴. "It's easy to restart," in those cases, Schreiber says, and many of her patients improve over time.

Tablets, too

There are two kinds of sublingual immunotherapy, the liquid drops mixed by allergists that Bortnick takes, as well as dissolvable tablets, available for single allergens. The Food and Drug Administration has approved four tablets, including one for ragweed, one for dust mites¹⁵, and two grass pollen allergy tablets, including one for timothy grass. The tablets melt within a minute or two of being placed under a person's tongue. The American Academy of Allergy, Asthma¹⁶ and Immunology says the tablets have been shown to provide long-term improvement.

The most common side effects of the tablets are temporary itching¹⁷ or burning in the mouth, which typically resolves quickly. Studies show the tablets have a good safety profile, though a severe allergic reaction is possible, so patients on SLIT tablets are also prescribed an epinephrine auto¹⁸ injector, known as an Epi-Pen. Typically, insurance covers the cost of these tablets.

"They're very effective," says Dr. Howard Boltansky, an allergist at Johns Hopkins, but the main downside is that the SLIT tablets each target only a single allergen. Since most people are allergic to multiple things, many patients prefer the drop option.

Off-label use

Boltansky has been in practice more than 35 years, and recently started offering SLIT allergy drops. (He sees patients at Hopkins' otolaryngology center in Lutherville, Maryland.) "The use of sublingual immunotherapy drops has increased because of the ability to include multiple allergens that are not available in the currently FDA approved tablet, " Boltansky says. And, as patients learn about this option, they like the flexibility¹⁹ and convenience, which helps explain the increased interest too, he says.

The drawback is that the SLIT allergy drops are not FDA-approved, so they are not covered by most insurance, Medicare or Medicaid.

Boltansky explains, when he makes the allergy drops, he uses the same FDA-approved extracts he uses to make allergy shots. The only difference is, instead of injecting the serum into a person's arm, it's put into a dropper-bottle, for the patient to administer at home. So, the drops are an 'off-label' use of the extracts. "I am completely comfortable using allergy extracts that are FDA approved in an 'off-label' fashion," Boltansky says, pointing to an excellent safety record.

In Europe, many doctors have used this approach for years, Boltansky says. And, just like with the SLIT tablet, doctors also prescribe an Epi-Pen to patients taking the allergy drops, though he says serious allergic reactions are rare.

When a patient begins sublingual immunotherapy, the exposure to the allergens is very controlled. "We start off giving people small amounts of what they're allergic to," Boltansky says. "Gradually, as their body says it's OK, we increase the dose a little more," he says. The drops are made from purified extracts, so Boltansky has a bottle of ragweed pollen, another for tree pollen, as well as extracts for dust mites and cats. So, if a person is allergic to all four of these, "we mix them together into a customized vial of allergy drops," he explains.

"When we start someone on immunotherapy, whether it be drops or a shot, we approach it as initially²⁰ a test," Boltansky says. They try it for about six months, and if they're doing well, they continue the treatment. He says about 80% of patients respond well, and the treatment usually lasts 3 to 5 years.

Not all allergists offer SLIT allergy drops, given the "off-label" status, and the lack of insurance coverage²¹. "There is a wide range of effective and ineffective doses of SLIT liquid formulations," according to the American Academy of Allergy, Asthma and Immunology. That's why people should find a doctor who is experienced at testing and formulating²² an immunotherapy treatment, such as a board-certified allergist. Also, some board-certified otolaryngologists (ear, nose and throat doctor, known as ENT's) have expertise²³ in SLIT.

Abigail Bortnick pays about $600 a year out of pocket for her allergy drops. "I did not love that it's not covered by insurance, but I thought the convenience factor outweighed²⁴ the cost," she says.

Boltansky says he'd like to see more research to show how effective SLIT allergy drops are in preventing symptoms. "I'm hopeful that over time the studies will get done and the FDA will review them, and that they will be approved," Boltansky says. In the meantime, doctors will continue the off label use for patients who are good candidates for immunotherapy.

1 pollen   

n.[植]花粉

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。
• He developed an allergy to pollen.他对花粉过敏。

2 allergies   

n.[医]过敏症；[口]厌恶，反感；（对食物、花粉、虫咬等的）过敏症( allergy的名词复数 )；变态反应，变应性

参考例句：

• Food allergies can result in an enormous variety of different symptoms. 食物过敏会引发很多不同的症状。 来自辞典例句
• Let us, however, examine one of the most common allergies; hayfever. 现在让我们来看看最常见的变态反应的一种--枯草热。 来自辞典例句

3 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

4 allergy   

n.(因食物、药物等而引起的)过敏症

参考例句：

• He developed an allergy to pollen.他对花粉过敏。
• The patient had an allergy to penicillin.该患者对青霉素过敏。

5 antihistamines   

n.抗组织胺药( antihistamine的名词复数 )

参考例句：

• Cough suppressants and some antihistamines may help quiet an annoying cough. 镇咳药和一些抗组织胺类药物能帮助驱除烦人的咳嗽。 来自互联网
• Antihistamines are the medications most commonly used to diminish allergic symptoms. 抗组胺药是药物最常用的，以减少过敏症状。 来自互联网

6 tamp   

v.捣实，砸实

参考例句：

• Then I tamp down the soil with the back of a rake.然后我用耙子的背将土壤拍实。
• Philpott tamped a wad of tobacco into his pipe.菲尔波特往烟斗里塞了一卷碎烟叶。

7 allergic   

adj.过敏的，变态的

参考例句：

• Alice is allergic to the fur of cats.艾丽斯对猫的皮毛过敏。
• Many people are allergic to airborne pollutants such as pollen.许多人对空气传播的污染物过敏，比如花粉。

8 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

9 slit   

n.狭长的切口；裂缝；vt.切开，撕裂

参考例句：

• The coat has been slit in two places.这件外衣有两处裂开了。
• He began to slit open each envelope.他开始裁开每个信封。

10 serum   

n.浆液，血清，乳浆

参考例句：

• The serum is available to the general public.一般公众均可获得血清。
• Untreated serum contains a set of 11 proteins called complement.未经处理的血清含有一组蛋白质，共11种，称为补体。

11 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。

12 congestion   

n.阻塞，消化不良

参考例句：

• The congestion in the city gets even worse during the summer.夏天城市交通阻塞尤为严重。
• Parking near the school causes severe traffic congestion.在学校附近泊车会引起严重的交通堵塞。

13 subsides   

v.（土地）下陷（因在地下采矿）( subside的第三人称单数 )；减弱；下降至较低或正常水平；一下子坐在椅子等上

参考例句：

• Emotion swells and subsides. 情绪忽高忽低。 来自《现代汉英综合大词典》
• His emotion swells and subsides. 他的情绪忽高忽低。 来自《现代英汉综合大词典》

14 recur   

vi.复发，重现，再发生

参考例句：

• Economic crises recur periodically.经济危机周期性地发生。
• Of course,many problems recur at various periods.当然，有许多问题会在不同的时期反复提出。

15 mites   

n.（尤指令人怜悯的）小孩( mite的名词复数 )；一点点；一文钱；螨

参考例句：

• The only discovered animals are water bears, mites, microscopic rotifers. 能够发现的动物只有海蜘蛛、螨和微小的轮虫。 来自辞典例句
• Mites are frequently found on eggs. 螨会经常出现在蛋上。 来自辞典例句

16 asthma   

n.气喘病，哮喘病

参考例句：

• I think he's having an asthma attack.我想他现在是哮喘病发作了。
• Its presence in allergic asthma is well known.它在过敏性气喘中的存在是大家很熟悉的。

17 itching   

adj.贪得的，痒的，渴望的v.发痒( itch的现在分词 )

参考例句：

• The itching was almost more than he could stand. 他痒得几乎忍不住了。 来自《现代汉英综合大词典》
• My nose is itching. 我的鼻子发痒。 来自《简明英汉词典》

18 auto   

n.(=automobile)(口语)汽车

参考例句：

• Don't park your auto here.别把你的汽车停在这儿。
• The auto industry has brought many people to Detroit.汽车工业把许多人吸引到了底特律。

19 flexibility   

n.柔韧性，弹性，（光的）折射性，灵活性

参考例句：

• Her great strength lies in her flexibility.她的优势在于她灵活变通。
• The flexibility of a man's muscles will lessen as he becomes old.人老了肌肉的柔韧性将降低。

20 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

21 coverage   

n.报导，保险范围，保险额，范围，覆盖

参考例句：

• There's little coverage of foreign news in the newspaper.报纸上几乎没有国外新闻报道。
• This is an insurance policy with extensive coverage.这是一项承保范围广泛的保险。

22 formulating   

v.构想出( formulate的现在分词 )；规划；确切地阐述；用公式表示

参考例句：

• At present, the Chinese government is formulating nationwide regulations on the control of such chemicals. 目前，中国政府正在制定全国性的易制毒化学品管理条例。 来自汉英非文学 - 白皮书
• Because of this, the U.S. has taken further steps in formulating the \"Magellan\" programme. 为此，美国又进一步制定了“麦哲伦”计划。 来自百科语句

23 expertise   

n.专门知识(或技能等)，专长

参考例句：

• We were amazed at his expertise on the ski slopes.他斜坡滑雪的技能使我们赞叹不已。
• You really have the technical expertise in a new breakthrough.让你真正在专业技术上有一个全新的突破。

24 outweighed   

v.在重量上超过( outweigh的过去式和过去分词 )；在重要性或价值方面超过

参考例句：

• This boxer outweighed by his opponent 20 pounds. 这个拳击选手体重比他的对手重20磅。 来自《简明英汉词典》
• She outweighed me by ten pounds, and sometimes she knocked me down. 她的体重超过我十磅，有时竟把我撞倒。 来自百科语句