A new diagnostic for Alzheimer's?

There is a report of research suggesting that a test of spinal fluid can identify many (perhaps all) Alzheimer's patients. That is a very positive research result, deservedly getting a lot of publicity.

Note that this is a preliminary result, and it will have to be replicated (ideally in larger samples of patients) for scientific credibility. Even it it is replicated, there would be have to be more work to figure out the probability that someone testing poverty would not have Alzheimer's and that someone testing negative would indeed have Alzheimer's, and to determine the risk to the patients involved in obtaining the sample.

The first rule of medical screening is not to screen if there is nothing that medicine can do based on the information. Without Alzheimer's specific treatment to cure or at least ameliorate the disease, a screening test for the disease would not be medically useful.

Perhaps the most important meaning of this result is further evidence that Alzheimer's is a disease. Only a few decades ago Dementia was thought to be a senility that was a normal part of aging. The increasing recognition that it is in fact an abnormal condition encourages research and development that may eventually lead to medical interventions to cure or ameliorate the disease.

Of course the discovery that proteins implicated in Alzheimer's are to be found in spinal fluid itself provides information on the evolution of the disease and contributes to the stock of knowledge of the disease.

I would say this is a result that should be exciting for those doing research and development on Alzheimer's disease, interesting for medical professionals treating patients with the disease, and of little immediate meaning for those suffering from the disease and their families.