|To detect Huntington's disease, new blood tests have been developed for the improvement of patient care / Photo by: angellodeco via 123rf|
New blood tests have been developed to accurately determine the time of the internal body clock and to diagnose neurodegeneration in Huntington’s disease. Both of these tests have been developed for the improvement of patient care.
A blood test laboratory analysis is usually performed on a blood sample that is extracted from a vein in the arm using a hypodermic needle or a fingerpick. A blood panel, on the other hand, is a multicomponent test for items such as glucose, or cholesterol. Common clinical blood panels include a basic metabolic panel or a complete blood count.
Blood tests may be used to detect substance abuse. Other applications include the detection of infectious disease, cancer, or autoimmune diseases. The tests may be broad or designed to detect a specific disease.
|Blood test is done by extracting blood from a vein in the arm using a hypodermic needle or a fingerpick. / Photo by: Alexander Raths via 123rf|
A Blood Test to Determine Your TimeSignature
A circadian rhythm is any biological process that shows a repeatable cycle or waveform over the course of approximately twenty-four hours. It is a common phenomenon in plants, animals, fungi, and cyanobacteria. The study of circadian rhythms is called chronobiology.
Circadian rhythms are self-sustaining or endogenous, whereas diurnal rhythms also occur over twenty-four hours, but must be actively maintained and do not necessarily always follow a twenty-four-hour cycle. Circadian rhythms are modulatable or entrainable by factors including light, temperature, and redox cycles.
A simple blood test called TimeSignature has been developed by a team of researchers led by Ravi Allada of the Department of Neurobiology, Northwestern University, Evanston, Illinois, and published in the journal PNAS.
According to an article published in Northwestern Now, TimeSignature identifies a person’s exact internal time compared to official external time. It requires just two blood draws, and the test is accurate to within 1.5 hours of the true internal state.
Previous circadian tests, that were as accurate as this, required blood draws every hour for several hours, making them impractical for clinical applications.
The ability to test whether a person’s body clock is misaligned with the external official time will allow research questions to be asked, like whether this is associated with disease states, such as Alzheimer’s or diabetes, or whether it impacts patient outcomes when admitted to hospital.
When the test becomes clinically available, it could be used to optimize dosing of medications.
The software and the algorithm behind it are openly available for other researchers, and interested parties. The Northwestern University has submitted a patent application for the blood test itself.
The test measures 40 different gene expression markers in the blood and can be taken at any time of day regardless of the quality of sleep the patient had the previous night.
The algorithm started out predicting the internal clock using the data from the entire genome of approximately 20,000 genes, however, these genes were whittled down to 40 through a process of iterative machine learning, as this panel had the strongest predictive power.
This approach identifies 40 genes in an unbiased way that are associated with circadian rhythms. Investigating these genes in the lab could lead to further insights into chronobiology.
Links between circadian misalignment, diabetes, depression, heart disease, and asthma have already been identified preclinically.
A New Blood Test for Very Early Stage Huntington’s Disease
One disease that may also be affected by circadian rhythms is the Huntington’s disease. It is an inherited autosomal dominant progressive neurodegenerative disorder caused by the mutation in the HTT gene.
It is characterized by a general lack of coordination and unsteady gait. Mood disorders and decline into dementia may occur. Moreover, coordination continues to worsen until the person cannot walk. Huntington's disease may occur at any age where about 8% of cases occur before the age of 20.
Prevalence rates per 100,000 have been reported by Liam Smeeth of the Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, as between 0.4 in Asia, and 7.33 in North America.
A new simple blood test has been developed to detect the earliest changes caused by Huntington's disease. It has been developed by a team of researchers led by Edward Wild of the Huntington’s Disease Centre, University College London, Institute of Neurology in the UK, published in the journal Science Translational Medicine.
The team developed a toolkit for the measurement of two early biomarkers of Huntington’s found in the brain and blood, neurofilament light protein, and mutant HTT. The test is intended to be used to select the earliest stage or prodromal patients for the clinical trial.
Furthermore, the blood test can detect neurodegeneration even before it is revealed by brain scans. The diagnostic is not approved for use in patients outside of clinical trials and the researchers envisage that it could become available as part of a package with a Huntington’s drug that successfully clears clinical trials. However, there are no approved treatments for the disease currently.
|Huntington disease is an inherited autosomal dominant progressive neurodegenerative disorder caused by the mutation in the HTT gene. / Photo by: Vitaliy Vodolazskyy via 123rf|