I recently got a blood test at Quest Diagnostics. These were the standard tests that doctors order for patients. My test measured kidney function, liver enzymes, cholesterol, testosterone and dozens of other metrics of bodily functions. Blood tests may become more comprehensive in the future, however. New research has identified proteins, found in a single drop of blood, that may hold clues to our health and the diseases we’re likely to develop years into the future. The following is from a summary from Drugs.com MedNews:
A single drop of blood might be able to predict the onset of dozens of diseases, a new study claims.Analysis of the protein “signatures” in a droplet of blood can predict 67 diseases, including blood cancers, degenerative nerve diseases, lung disease and heart failure, researchers reported July 22 in the journal Nature Medicine.These protein “signatures” outperformed other standard tests that used measures like blood cell counts, cholesterol levels, kidney function and blood sugar levels to predict the 67 diseases, researchers report.
Will identifying diseases earlier result in better treatment and diseases avoided? It remains to be seen. Current blood tests identify when blood chemistry is out of range but do not necessarily explain why.
Furthermore, some bodily functions have chemistry with a broad range of normal. Of course, improvements in blood chemistry laboratory testing are always welcome.
“Several of our protein signatures performed similar or even better than proteins already trialed for their potential as screening tests, such as prostate specific antigen for prostate cancer,” said lead researcher Julia Carrasco Zanini Sanchez, a postdoctoral researcher with the Precision Healthcare University Research Institute at Queen Mary University of London.Such a simple blood test could not only improve early detection of diseases, but might also help in the search for new medicines, said senior researcher Robert Scott, vice president and head of human genetics and genomics at the pharmaceutical company GSK.“A key challenge in drug development is the identification of patients most likely to benefit from new medicines,” Scott said.
Years ago, the newsletter, Access to Energy, predicted that at some point in the future mass spectrometry could be used to identify all manner of diseases and conditions. The idea again appeared four years ago in Empowering Clinical Diagnostics with Mass Spectrometry:
Advances in mass spectrometry (MS)-based disease biomarker discoveries are continuously expanding the clinical diagnostic landscape. Although a number of MS-based in vitro diagnostics are already adopted in routine clinical practices, more are expected to undergo transition from bench to bedside in the near future.
Identifying or predicting the onset of disease has been the holy grail of medicine for quite some time. It is easy to understand the benefits with identifying cancer earlier, but would it help prevent the plethora of other diseases that we already know are correlated with unhealthy lifestyles?
What could go wrong with identifying potential diseases and conditions early? Plenty. Let’s assume the blood tests have an accuracy rate of, say, 75%. That sounds good until you realize your false positive (or negative) rate is 25%. There currently exist diagnostic tools such as MRIs, CT scanners and other devices. Medical experts advise against using diagnostic tools on asymptomatic patients, since the risk of false positive results increases unnecessary medical care in the face of no apparent problem. The solution, at least so far, is the U.S. Preventive Services Task Force. The Task Force studies preventive services and decides which ones should be performed and how frequently. This link leads to their current recommendations. I also wonder about the moral hazard of having blood tests that can identify potential health risks much earlier. Recommendations aimed at preventing diseases attributed to unhealthy lifestyles go unheeded. Would newer tests change that? Many people may take the attitude they can eat unhealthy food since blood tests can tell whether it’s influencing their health in a measurable way.
This all goes back to an earlier post I wrote about the economics of prevention. Preventive care costs money rather than saves money since you must screen healthy people to find the few unhealthy ones. Some people will also ignore results until they become much more dire. That should not be construed to mean preventive care is a bad thing. It’s an investment in both health and peace of mind.