Elizabeth Holmes, the 30-year-old founder of the blood-test company Theranos who dropped out of Stanford at 20 because classes were getting in the way of her work, recently told the New Yorker that her mother and grandmother both fainted at the sight of syringes. “I really believe that if we were from a foreign planet and we were sitting here and said, ‘O.K., let’s brainstorm on torture experiments,’ the concept of sticking a needle into someone and sucking blood out slowly, while the person watches, probably qualifies,” she said.
So Holmes, who may have a stronger backbone than her forebearers but still claims an aversion to needles, has spent the past decade developing a new approach to blood draws: namely, that a simple finger prick can and should do the trick faster and even better, at a fraction of the cost of a traditional blood draw.
The importance of Holmes’ work, of course, leans heavily on the past decade’s progress in gene sequencing. Blood tests can now tell us so much more about our health and our genetic makeup than ever before, and promise to expand on that even further in the coming years. (Seven billion lab blood tests are already done every year, accounting for nearly 2.5 percent of all health spending.)
“It’s kind of amazing,” Dr. Stephen Quake, a bioengineer at Stanford University whose lab invented the new prenatal tests that can screen for genetic anomalies using only a maternal blood draw, recently told me. “It’s changing incredibly rapidly. We published the paper in 2008 – a purely academic paper, just a small number of samples showing how to do it and that the principal worked.
“I thought it would take a decade before any real tests came out, but within three years big clinical trials were validating this on thousands of women, and by 2014 a million women got tested. It’s just astounding to me. People have told me they think it’s the fastest molecular diagnostic ever developed.”
Prenatal testing is just one of several areas where blood draws are proving vital. Dr. Quake and his colleagues call the new generation of testing a “molecular stethoscope” because these tests allow us to see inside the body at the molecular level. (The actual stethoscope, they argue, was misnamed; it doesn’t scope at all, but listens, and therefore should have been called a stethophone.)
“Blood is kind of like the septic system of the body; it touches everything,” Quake told me. “So every part of your body is contributing molecules to your blood, and if you have the right lens, the right molecular stethoscope, you can glean all sorts of interesting things.”
In many instances, blood draws provide information about our health that is otherwise only gleaned through more invasive procedures – such as, in the case of prenatal testing, amniocentesis. Many of these procedures are not only costly and uncomfortable but come with complications; amniocenteses actually run the risk of fetal injury and even death, something Quake calls “unacceptable.”
Quake’s team has also recently shown how to sequence the whole genome of a baby in utero through a maternal blood draw, opening the door for even more lines of investigation into an unborn child’s health. (Whether it will be developed into a clinical test remains to be seen.) And a group out of Temple is working on a test that could spot abnormal fetal neurodevelopment, including from alcohol, antidepressants, and methamphetamines. (In the U.S., alcohol is the leading known preventable cause of both developmental and physical birth defects.)
Beyond prenatal testing, a large chunk of new blood tests are being developed to quickly diagnose and track cancers and infectious diseases. The FDA recently approved a new test that distinguishes between two viruses that can cause adult T-cell leukemia/lymphoma and myelopathy. It may soon be possible to diagnose breast cancer before a patient is even symptomatic. (Overriding mammograms and X-rays has many appeals, not least of which is the cost savings.) And one new test being studied could diagnose colorectal and lung cancers with just a drop of blood.
Blood tests can now catch such subtle clues to the development of diseases that they can also be predictive rather than just diagnostic. One has recently been shown to accurately predict a patient’s risk of developing heart disease in the next 15 years – which could better inform the development of medications, and the adoption of better diets and lifestyles, which taken together may even prevent the disease altogether. Ditto tests that can predict the development of Alzheimer’s a decade before a patient exhibits symptoms. Even if its development cannot be prevented, many argue it can be slowed, or at least better managed, if caught so early.
Still, better tests don’t necessarily result in better health. The main value in diagnosing diabetes, for instances, is simply to “confirm what we already know: that people should be eating a better diet and exercising more,” Andy Ellner, co-director of the Harvard Medical School Center for Primary Care, told the New Yorker in Holmes’ profile. So even given, as Ellner put it, “a big shift in power, control, and authority of health data from doctors to patients,” it is ultimately up to the patients to use it to their own benefit.