阿尔茨海默病的基因检测可能提高诊断的可靠性

在全国26个联邦资助的阿尔茨海默病中心(adc)迄今为止最大的合作调查中，哥伦比亚大学内科和外科医学院的研究人员与美国国家衰老研究所(NIA)合作发现，阿尔茨海默氏病的载脂蛋白e基因测试加上全面的临床评估可能有助于确诊该病。这项研究报道,在2月18日的《新英格兰医学杂志》上,强调ApoE-4基因测试的结果——检测的载脂蛋白E基因的DNA (ApoE)患者的血液,本身是不确定的,不提供足够的证据来诊断阿尔茨海默氏症。研究人员发现，当ApoE测试与彻底的检查一起进行时，阿尔茨海默病的临床诊断的验证可能会大大提高。1995年，针对阿尔茨海默病风险的首次商业测试促使公共卫生专家呼吁进行更多的研究，并为个人基因信息提供特殊法律保护。当时，科学界对“阳性测试”的含义没有达成共识。美国每年花在老年痴呆症患者身上的钱超过1000亿美元。“载脂蛋白E基因型可能是不可否认的阿尔茨海默病的遗传危险因素,但其作为辅助诊断手段却没有得到足够关注直到现在,”理查德马斯说,医学博士,M.S.E,资深作者和格特鲁德·h·Sergievsky神经学教授,哥伦比亚长老会大学精神病学和公共卫生(流行病学)。“这项研究首次澄清了载脂蛋白e检测在帮助诊断和治疗阿尔茨海默病方面的作用。”美国国立卫生研究院的医学博士Creighton Phelps说:“我们不能低估增加医生诊断这种严重疾病的信心的作用。” "When facing a family who must bear the weight of such devastating news, a majority of doctors would appreciate as many tools as possible to help them in their certainty of diagnosis and based on this research, ApoE testing may be one such tool." Investigators, led by Dr. Mayeux, reviewed the eligibility of men and women referred to ADCs for diagnosis of dementia. The study examined records of 1,108 women and 1,080 men. Each patient examined had a battery of clinical and behavioral tests, followed by numerous laboratory and brain imaging studies. The patients were followed throughout the course of their disease and their brains were examined upon death. Based on brain autopsies Dr. Mayeux found that 93 percent of the patients who were found to have Alzheimer's, i.e, their brains showed clear evidence of Alzheimer's-related changes, had been diagnosed by a physician as having the disease. However, 45 percent of those found to have other forms of dementia at the time of brain autopsy had also been diagnosed by physicians as having Alzheimer's. This high rate of false positive diagnoses (45 percent) shows the limitations of using recommended clinical criteria alone. Dr. Mayeux and colleagues examined the effect of the ApoE genotype in reducing false positive diagnoses and in adding to the assurance of clinical diagnoses. By using the ApoE genotype only in patients who first met clinical criteria for Alzheimer's, the false positive rate of diagnosis decreased from 45 percent to 16 percent. The addition of ApoE genotyping to an arsenal of other tests that are used to determine Alzheimer's status may be useful, but Dr. Mayeux cautions that the study was "done in a selected group of people who receive treatment in specialized centers for Alzheimer's disease, and that the results do not apply to individuals of other ethnic groups or health care situations. More broad-based study is needed before these results can be assumed to be universally applicable." Other Columbia authors were Steven Shea, M.D., and Ming-xin Tang, PhD.