A Wall Street Journal report published Thursday alleges that Theranos, the $9-billion health startup whose blood tests can allegedly be done with a single drop, has a problem.
For one thing, the report finds, its tests don’t give the most accurate results.
One potential reason for that inaccuracy is that a majority of the samples Theranos processes are actually done with traditional blood testing, which means the samples have to be diluted to meet those machine’s diagnostic standards.
“Anytime you dilute a sample, you’re adulterating the sample and changing it in some fashion, and that introduces more potential for error,” says Timothy R. Hamill, vice chairman of the University of California, San Francisco’s department of laboratory medicine told the Journal.
And that resulted in inaccurate results, the Journal found.
In particular, the results for Theranos’ potassium test for one Arizona woman came back at the “threshold considered critical,” the Journal reported. Having high potassium levels could be a sign of kidney problems. Follow-up tests using a normal testing method came back normal.
Former employees that spoke with the Journal also said they saw problems with the potassium test.
Yet Theranos’ general counsel Heather King denied the test had any problems.
In another example, the Journal noted another Arizona woman who had abnormally high levels on all six of the Theranos tests she took:
- For calcium, the Theranos test told her she had 11.8 milligrams per deciliter (above the normal range), while a hospital test told her she had 9.2 milligrams per deciliter, which was in the normal range. High calcium levels, while fairly common, can be an indication of more serious conditions, including kidney disease, cancer, and a condition called primary hyperparathyroidism. These results were similar on the total protein and liver enzymes tests she took. Having high levels of total protein or liver enzymes could also be linked to some serious conditions. For the glucose test, the Theranos result was still above the hospital test results, though that gap was much closer (Theranos’ test reported 103 milligrams per deciliter, while the hospital reported 99 milligrams per deciliter, at the higher end of the normal range). High glucose levels could be a sign of diseases such as diabetes.
Theranos has since fired back against the Journal’s claims. In a release, Theranos said it had “presented the facts to [the Journal] reporter to prove the accuracy and reliability of its tests and to directly refute these false allegations, including more than 1,000 pages of statements and documents.”
Theranos deferred to its press release for comment, and did not respond to a request to see the statements and documents they referred to.
Read the full report from the Wall Street Journal.