Alzheimer’s disease in men associated with loss of the Y chromosome
A group of Swedish researchers has found evidence that may help explain why some men could be more likely to develop Alzheimer’s than others. The researchers looked at men with lifetime-acquired loss of chromosome Y, or LOY for short. Biological females have two X chromosomes, while males have one X and one Y chromosome. Age-related loss of the Y chromosome is a fairly common condition, affecting at least 15% of men over the age of 70. LOY is associated with a greater risk of mortality (i.e., greater likelihood to die at any given age), as well as higher incidence of certain cancers. It’s not known for sure what causes LOY, though studies have found that it can be induced by smoking.
The researchers in this study looked at the prevalence of LOY in men’s blood cells to see if it was related to their risk of Alzheimer’s. They found that men with Alzheimer’s tended to have greater levels of LOY in their blood, on average nearly three times the levels of the control subjects. The reverse was also true, in that men with LOY were 6.8 times more likely to be diagnosed with Alzheimer’s during the course of the study. These results suggest a possible mechanism for the link between smoking and an increased risk of Alzheimer’s. Further studies with a larger sample size are being planned in order to confirm these results. Click to read more
A possible blood test to detect preclinical Alzheimer’s disease
Researchers from Rowan University have designed a test that may be able to detect the early stages of Alzheimer’s disease. Though these kinds of tests have been suggested before, they’ve often required extraction of cerebrospinal fluid, a painful and potentially dangerous procedure. Other tests that rely on neuroimaging are less invasive but can be expensive and less accurate. The newly-announced test is unique in that it requires only a simple blood draw. The test works by detecting autoantibodies, molecules that can target our own body’s cells for destruction by the immune system, normally as a way of clearing away dead cells and tissues. The levels of these autoantibodies are unique to each person and can be used to detect certain diseases.
The researchers first used the older test to examine cerebrospinal fluid from individuals with mild cognitive impairment. Individuals who the test deemed were likely to develop Alzheimer’s then had their blood analyzed to search for differences in the levels of various autoantibodies. The researchers identified a small set of autoantibodies whose levels in the blood could be used to distinguish people likely to develop Alzheimer’s from healthy control subjects with 100% accuracy. This test might be a faster, easier, and less expensive method than current methods for allowing early diagnosis of Alzheimer’s. However, one possible flaw with the study is that the researchers assumed the cerebrospinal fluid test to which their new blood test was compared is also 100% accurate, which so far has not been definitively proven. The test will need to be further analyzed over a longer period and with a larger sample size before it’s ready to be introduced to clinics. Click to read more
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