Alzheimer’s blood test catches 90% of early dementia cases, study finds
Blood tests that can detect 90% of Alzheimer’s cases could revolutionize access to Alzheimer’s treatment, studies say.
A new study has found that a combined blood test for cognitive decline can accurately determine whether memory loss is due to Alzheimer's disease with 90% accuracy. This is significantly more accurate than the diagnoses made by neurologists and other memory specialists, who correctly identified Alzheimer's in only 73% of cases. Primary care doctors had an even lower accuracy rate of 61%.
One component of the blood test is the plasma phosphorylated tau 217, or p-tau217. This biomarker is one of several that scientists are evaluating for the diagnosis of mild cognitive impairment and early-stage Alzheimer's disease. The test measures the level of tau protein 217, which is a strong indicator of amyloid pathology, a key feature of Alzheimer's disease.
According to Dr. Sebastian Palmqvist, an associate professor and senior consultant neurologist at Lund University in Sweden, the levels of p-tau217 in the blood can increase significantly in patients with Alzheimer's disease. At the dementia stage, the levels of this protein can be more than eight times higher compared to elderly individuals without Alzheimer's.
Previous research has also supported the effectiveness of p-tau217 tests in identifying elevated levels of beta-amyloid and tau, which are hallmark signs of Alzheimer's disease. The new study combined the p-tau217 test with another blood biomarker called the amyloid 42/40 ratio, which measures different types of amyloid proteins. The combination of these tests, known as the amyloid probability score, was found to be highly predictive.
Dr. Maria Carrillo, chief science officer of the Alzheimer's Association, expressed her enthusiasm for the potential of blood tests in the early diagnosis of Alzheimer's disease. She highlighted the p-tau217 blood test as the most specific and valid marker for Alzheimer's among the current options. Carrillo also emphasized the impact of highly accurate blood tests on accelerating Alzheimer's research and the development of new medications.
The p-tau217 blood test is unique as it can only detect the presence of amyloid plaques in the brain, which is an early indicator of Alzheimer's disease. This test offers valuable insights into the neuronal damage caused by tau, an essential biomarker for Alzheimer's diagnosis and differentiation from other types of dementia.
The study, published in JAMA Neurology, involved 1,213 individuals with an average age of 74 who underwent cognitive evaluations in primary care and specialty clinics in Sweden. The blood tests combined p-tau217 with blood measures of beta-amyloid 40/42 to develop a final score. The accuracy of the combined blood test was confirmed through a spinal fluid tap, currently considered a gold standard for Alzheimer's diagnosis.
However, the current tools available to doctors, such as patient interviews, brief cognitive tests, and CT scans, have led to relatively low accuracy rates in Alzheimer's diagnosis. The study highlights the need for more accurate and accessible diagnostic tools, such as blood tests, to improve patient care and speed up the development of effective treatments for Alzheimer's disease.
While the positive results of blood tests for Alzheimer's are promising, more research and guidelines are needed before they become routinely available in primary care settings. In the meantime, individuals can take proactive steps to prevent or slow cognitive decline through regular exercise, a healthy diet, and managing vascular risk factors. The development and validation of highly accurate blood tests for Alzheimer's disease represent hopeful advancements in the field, bringing us closer to transformative improvements in patient care and treatment options.
One component of the blood test is the plasma phosphorylated tau 217, or p-tau217. This biomarker is one of several that scientists are evaluating for the diagnosis of mild cognitive impairment and early-stage Alzheimer's disease. The test measures the level of tau protein 217, which is a strong indicator of amyloid pathology, a key feature of Alzheimer's disease.
According to Dr. Sebastian Palmqvist, an associate professor and senior consultant neurologist at Lund University in Sweden, the levels of p-tau217 in the blood can increase significantly in patients with Alzheimer's disease. At the dementia stage, the levels of this protein can be more than eight times higher compared to elderly individuals without Alzheimer's.
Previous research has also supported the effectiveness of p-tau217 tests in identifying elevated levels of beta-amyloid and tau, which are hallmark signs of Alzheimer's disease. The new study combined the p-tau217 test with another blood biomarker called the amyloid 42/40 ratio, which measures different types of amyloid proteins. The combination of these tests, known as the amyloid probability score, was found to be highly predictive.
Dr. Maria Carrillo, chief science officer of the Alzheimer's Association, expressed her enthusiasm for the potential of blood tests in the early diagnosis of Alzheimer's disease. She highlighted the p-tau217 blood test as the most specific and valid marker for Alzheimer's among the current options. Carrillo also emphasized the impact of highly accurate blood tests on accelerating Alzheimer's research and the development of new medications.
The p-tau217 blood test is unique as it can only detect the presence of amyloid plaques in the brain, which is an early indicator of Alzheimer's disease. This test offers valuable insights into the neuronal damage caused by tau, an essential biomarker for Alzheimer's diagnosis and differentiation from other types of dementia.
The study, published in JAMA Neurology, involved 1,213 individuals with an average age of 74 who underwent cognitive evaluations in primary care and specialty clinics in Sweden. The blood tests combined p-tau217 with blood measures of beta-amyloid 40/42 to develop a final score. The accuracy of the combined blood test was confirmed through a spinal fluid tap, currently considered a gold standard for Alzheimer's diagnosis.
However, the current tools available to doctors, such as patient interviews, brief cognitive tests, and CT scans, have led to relatively low accuracy rates in Alzheimer's diagnosis. The study highlights the need for more accurate and accessible diagnostic tools, such as blood tests, to improve patient care and speed up the development of effective treatments for Alzheimer's disease.
While the positive results of blood tests for Alzheimer's are promising, more research and guidelines are needed before they become routinely available in primary care settings. In the meantime, individuals can take proactive steps to prevent or slow cognitive decline through regular exercise, a healthy diet, and managing vascular risk factors. The development and validation of highly accurate blood tests for Alzheimer's disease represent hopeful advancements in the field, bringing us closer to transformative improvements in patient care and treatment options.