Assistant-in-Charge: Steven Wu(吳信賢)
Member-in-Team: Shelley Chu(朱琪), Yen-Han Peng(彭雁函)
Article Reference: CNN Health
(https://edition.cnn.com/2018/10/31/health/appendectomy-parkinsons-disease-study/index.html)
Pubilshed Date of Article: 1st November 2018
Original Article:
Had your appendix removed? Your Parkinson’s risk may be 20% lower
It may be painful, but there could be an unusual upside to appendicitis: Those who have had their appendix removed are 20% less likely to develop Parkinson’s disease, according to a new analysis of more than 1 million people in Sweden.
The tiny organ, which is attached to and opens into the lower end of the large intestine, may contribute to this brain disorder that affects nearly a million Americans, the researchers say. Their study was published Wednesday in the journal Science Translational Medicine.
“Parkinson’s disease is multisystem disorder,” said Viviane Labrie, senior author of the study and an assistant professor at the Van Andel Research Institute in Michigan. “And so there’s likely to be many sites of origin in terms of where Parkinson’s disease starts, the [gastrointestinal tract] being one of them. For other people, it may begin in the brain.”
‘Not just a movement disorder’
Parkinson’s disease is not only common, with 60,000 new diagnoses each year, it is also incurable. Symptoms include tremors or shaking of the fingers, hands, legs or feet; stiffness; difficulty balancing; depression; and gastrointestinal disturbances including constipation. Research has shown that gastrointestinal symptoms can begin up to 20 years earlier than movement symptoms.
“In the last decade, it’s become evident that Parkinson’s disease is not just a movement disorder,” Labrie said in a podcast. One of the most common non-motor symptoms of Parkinson’s is gastrointestinal tract issues, so some scientists believe the disorder might begin there, she said. In fact, the appendix contains a protein, alpha-synuclein, that is known to accumulate or clump together in the brains of Parkinson’s patients, she noted.
Searching for connections between Parkinson’s and the appendix, Labrie and her colleagues analyzed medical data for 1.6 million people in Sweden. This general population survey showed that having an appendectomy is linked to a 19.3% reduced risk of developing Parkinson’s disease, according to the researchers.
Separately, they examined the records of 849 Parkinson’s patients and found that an appendectomy was associated with delayed onset of the disorder by 3.6 years, on average.
“Alpha-synuclein is a protein that doesn’t like to stay put. It’s able to move from neuron to neuron, and it has been shown that it can travel,” Labrie said. Potentially, the protein can travel up the vagus nerve connecting the gastrointestinal tract and the brain.
“If it were to enter the brain, it can seed and spread from there and have neurotoxic effects that could eventually lead to Parkinson’s disease,” she said.
The study earned applause from some and criticism from others.
Do not get an appendectomy to ward off Parkinson’s, experts say
James Beck, chief scientific officer of the Parkinson’s Foundation and an adjunct associate professor in the Department of Neuroscience and Physiology at New York University School of Medicine, said the new study is “solid.”
Although the research shows that the disorder “may start in the gut,” he said, “it is not an indication that people should get an appendectomy if they’re worried about Parkinson’s.”
Beck, who was not involved in the study, said it lays the foundation for more research into other contributors to Parkinson’s disease, including environmental factors. At the same time, he said, the research raises questions such as, are people having bad gastrointestinal illness that may lead to proteins leaving the gut and getting into the brain?
Overall, finding a link between the appendix and Parkinson’s is significant, he said. “Understanding where that 20% is coming from could be useful in the bigger scheme of things for all people with Parkinson’s disease,” Beck said.
Kevin McConway, emeritus professor of applied statistics at the Open University in the UK, told the Science Media Centre that the study is “competent,” yet he also had a criticism based on the researchers’ use of statistics.
“People who had their appendix removed in early life will, on average, differ from people who didn’t, in several ways,” said McConway, who was not involved in the research. “Any of these differences might be the cause of the decreased risk of Parkinson’s disease in those who had their appendix out, rather than the removal of their appendix.”
He said that it's "not the case that cause and effect has been established beyond doubt" by the study.
Translation of Article:
闌尾炎(又稱為盲腸炎)也許會令你感到疼痛不已，但它可能有一個顛覆你想像的益處。根據最新研究指出，在超過一百萬名的瑞典受試者中，切除闌尾的人得到帕金森氏症的機率比一般人少了兩成。
研究者指出，這個開口於大腸底部的微小器官將會對影響超過一百萬個美國人的腦部失調疾病有所貢獻。這項研究在本周三（2018年10月31日）被發表在《科學轉化醫學Science Translational Medicine》期刊上。
此項研究的主導人，美國密西根州范安德爾研究所（Van Andel Research Institute）的助理教授薇薇安•拉布莉（Viviane Labrie）說道：「帕金森氏症是一個牽涉到眾多體內系統失調的疾病，因此帕金森氏症的發生可能源自於很多地方，有些人可能源於腸胃道，而對於另一群人來說則可能是源於腦部。」
不只是行為失調
伴隨著每年新增六萬病例的發生率，帕金森氏症常見卻難以治癒。其症狀包含了震顫、四肢發抖、肢體僵硬、平衡失調、抑鬱以及腸胃道功能障礙，例如便秘。研究證實腸胃道症狀比行為症狀可能提早至多二十年出現。
「十年前，帕金森氏症即被證實並不只是行為失調的疾病。」拉布莉在播客（podcast，一種數位媒體）上說道。她談到，許多科學家認為在帕金森氏症的症狀中，最常見的非行為失調症狀與腸胃道有所相關，故此種生理失調疾病可能來源於此。同時她提及，在闌尾中含有一種稱作α-突觸核蛋白（α-synuclein）的蛋白質，會在帕金森氏症病人的腦中累積或形成塊狀聚集。
為了尋找闌尾與帕金森氏症之間的關聯性，拉布莉和她的研究團隊分析了160萬名瑞典人的醫療資料。研究者由這項大規模的人口調查中得知，進行過闌尾切除手術的人得到帕金森氏症的機率降低了19.3%。
此外，調查849位帕金森氏症患者的病歷後發現，闌尾切除手術平均能讓帕金森氏症的發病時間晚3.6年。
「『α-突觸核蛋白』是一種不安定的蛋白，它會在神經之間穿梭，並且已被證實可以到處傳播。」Labrie說道。這個蛋白有可能進入連結腦與腸胃的迷走神經。
「假使它進入腦部，它會從此扎根並且散播，產生神經毒性，最終導致帕金森氏症。」她說。
然而外界對這項研究的評價趨於兩極。
專家認為，千萬別以切除闌尾的方式來避免帕金森氏症
帕金森基金會的科學負責人、同時也是紐約大學醫學院神經科學與生理學系的兼任副教授，James Beck說，這項新研究是「可信賴的」。雖然研究顯示這個疾病「可能」從腸道開始，但「這並不表示人們應該要為了避免帕金森氏症而選擇切除闌尾。」
雖然並沒有參與探討，Beck教授認為這份研究能為其他帕金森氏症影響因素子的往後研究奠定基礎，包括環境因素等。與此同時，他認為這也延伸出一些值得探究的問題，例如：胃腸道疾病的患者是否會導致蛋白質離開腸道並進入大腦？
Beck教授也表示，不論如何，找到闌尾和帕金森氏症之間的關聯很有意義。「了解這所謂因割除闌尾所降低的20%致病率從何而來將會有利於擴大研究規模，而對帕金森氏症患者有所幫助。」
英國公開大學（the Open University in the UK）應用統計學的榮譽教授，Kevin McConway告訴科學媒體中心，這項研究「很優秀」，但他對研究者的統計方式略帶質疑。
「平均而言，於早年移除闌尾的人，本來就會跟未移除的人有某些方面的不同。」雖然McConway教授沒有參與研究，但他認為，「造成帕金森氏症風險降低的差異來源，可能就是源於這些方面的差異，而非源於移除闌尾這件事。」
他表示，經由這項研究，「它們之間的因果關係仍未有明確的定見」。