Oct. 25, 2021 — Once valued at over $9 billion {dollars}, it appeared like Theranos was going to vary the world of routine blood testing. Their declare was revolutionary: Using blood from a finger prick, they may run over 200 totally different exams. With a visit to an area pharmacy, somebody might get testing executed with out getting blood drawn and obtain the ends in hours, moderately than days. What’s extra, Theranos mentioned dozens of exams may very well be run on one drop of blood alone, and these exams would value a fraction of conventional lab work.
But famously, Theranos’s home of playing cards got here tumbling down. The microwave-sized machine that supposedly might run these exams, dubbed the “Edison,” merely didn’t work. What got here as a shock for Silicon Valley and the funding world was no shock to these within the blood testing business.
“It was like saying you could build a flying car that is also a submarine, for the same price as an entry-level Toyota,” says Sheldon Campbell, MD, PhD, a professor of laboratory drugs at Yale School of Medicine.
Unlike the world of computing expertise, the place one breakthrough can revolutionize your entire discipline, progress in blood evaluation is steadier and slower, just like the automotive business, Campbell says. While the automotive business has developed hybrids and electrical autos, the foundations of a automotive have remained the identical.
“The drive trains haven’t changed, and the tires haven’t changed,” he says. “It’s pretty mature technology.”
Similarly, course of in blood testing is evolutionary, moderately than revolutionary.
When you get blood exams executed, the technician makes use of a needle to attract blood from a vein in your arm right into a blood assortment tube. Each tube collects between 1/2 to 1 teaspoon of blood, and the technician will fill one to a number of tubes in the course of the draw, relying on the variety of exams your physician ordered. This provides lab technicians loads to work with, and medical doctors may even request further exams after a pattern is taken.
About half of blood is made up of crimson and white blood cells, whereas the opposite half is liquid. Most diagnostic exams use the liquid portion, which means that solely half of a normal pattern is often used for testing. You can even use blood from a finger prick, often known as a capillary pattern, for testing, however it may be tougher. These samples — a couple of drops of blood — are 30 to 100 instances smaller than your normal blood draw. Unlike blood taken instantly from a vein, capillary blood is combined with liquid from tissues, which may contribute to an inaccurate outcome.
For easier exams like checking glucose ranges, one thing that folks with diabetes do a number of instances a day, utilizing a small quantity of blood from a finger works simply tremendous. In truth, essentially the most superior glucose screens may even produce correct outcomes with a fraction of the blood wanted for a typical capillary pattern.
“You’re literally able to take the capillary sample, place it on your test strip, put it into your device, and this simple one-step chemical reaction takes place in that testing chamber so that you can get a glucose measurement,” says Kimberly Sanford, MD, president of the American Society of Clinical Pathology.
But transferring extra sophisticated exams that require a number of chemical reactions out of central laboratories and into clinics will get trickier, Sanford says. Running a number of exams on a couple of drops of blood additionally provides further engineering challenges, as a specific amount of blood is critical for every outcome.
Diagnostic testing that happens outdoors of the lab, often known as point-of-care testing, can also be costlier than testing executed in a centralized lab. While these bigger labs are constructed to handle a number of samples at one time, point-of-care testing is completed separately.
To actually get your bang in your buck, the exams have to be simple, quick, and, most significantly, correct. Unless these in-office exams can present clinicians with all the data they should make a medical determination, it makes extra sense to ship off samples to a lab.
“No point of care test, however simple, is easier than checking off one more box on a lab order form,” Campbell says.
But regardless of these hurdles, bits and items of laboratory testing have been making their method to clinics and bedside care.
“They’re similar technologies to what we would use in the main laboratory on the larger analyzers, but they miniaturize them make them more portable,” says James H. Nichols, PhD, a professor of pathology, microbiology, and immunology at Vanderbilt University Medical Center in Nashville.
Advances in microfluidics — techniques that course of very small quantities of liquid for testing — have made it doable to run a number of diagnostic exams on a couple of drops of blood, simply not as many as Theranos had promised.
Abbott Laboratory’s i-STAT, for instance, a handheld blood analyzer with test-specific, single-use cartridges, can ship a number of outcomes from a normal finger-prick pattern. Their Chem 8+ cartridge can ship outcomes for 9 metabolic measures with a couple of drops of blood. To carry out a check, the person locations two or three drops of complete blood on the check cartridge, which is then inserted into the analyzer. A brand new check cartridge is used for every affected person.
The i-STAT delivers lab-accurate testing for blood gases, electrolytes, chemistries, coagulation, hematology, glucose, and cardiac markers, an Abbott spokesperson says. Results can be found in 2 minutes.
While the machine was designed for pressing care settings, it’s now additionally used at well being gala’s, medical tents at occasions, and lots of different cell care settings, Nichols says.
A number of tabletop blood chemistry analyzers that carry out these similar varieties of exams are additionally obtainable for each emergency care in addition to outpatient clinics. The Piccolo Xpress, for instance, a transportable analyzer roughly the dimensions of a shoebox, can run as much as 14 exams on a finger-prick pattern of blood and ship ends in 12 minutes.
Complete blood counts, a standard group of exams that depend the variety of white blood cells, crimson blood cells, and platelets in your blood, have additionally begun to make their manner into main care and different outpatient clinics, Nichols says. With a couple of drops of blood, a clinician can get ends in 3 minutes or much less.
Looking ahead, “there’s also going to more infectious disease [testing] moving from the main laboratory and out into the community,” Nichols says, which partly has been pushed by the significance of speedy COVID-19 testing. For instance, creating further speedy, easy-to-use exams for illnesses extra frequent outdoors of the United States, like malaria and dengue fever, might assist enhance entry to laboratory diagnostics in creating nations, he says.
“It’s going to be an evolutionary process,” Campbell says, as bits and items of laboratory testing proceed to be tailored to extra speedy and moveable applied sciences. “And it will work for both directions. The point-of-care market is clearly expanding, and people are coming up with clever ideas and ways of doing things at point-of-care, but the lab-based side won’t be static either,” he mentioned. “They’ll sort of grow toward each other.”
