It's enough to make your blood curdle: Theranos, a one-time hot start-up, has voided or restated results from 2014 to 2015 for tests run on its proprietary blood-testing device.

The company has issued tens of thousands of corrected reports, with some results voided and others corrected, according to The Wall Street Journal. Theranos spokeswoman Brooke Buchanan declined to specify the number of corrected or voided results, although she told CBS MoneyWatch that the decision was voluntary and that the company did so "out of an abundance of caution." Letters and emails were sent to both physicians and patients, she said.

That may not be reassuring to the thousands of customers who received a notice that their blood tests over a two-year period are faulty or no longer valid. Theranos said patients should review the data with their physicians. Consumers who received voided results may have their blood retested through Theranos or can receive a refund, Buchanan said. Corrected results don't need to get retested, she added.

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It may be an understatement that the company has lost patients' and the medical industry's goodwill and tarnished its reputation over the past year. The latest revelation comes just weeks after a government report found that Theranos' blood-testing at its California lab was plagued by problems, ranging from unqualified personnel to failing to keep freezers at the proper temperatures.

Earlier this year, the Icahn School of Medicine at Mount Sinai found that Theranos' tests were more often outside the normal range than rival testing services. Theranos disputed the report. In January, the Centers for Medicare and Medicaid Services said its practices "pose immediate jeopardy to patient health and safety."

Theranos has taken steps to remedy the problems, including putting in new laboratory leadership and corrective measures, Buchanan said. Asked about why consumers should continue to have faith in the company and its testing after the missteps, she said, "Patient safety is our utmost priority." The company is working "to make sure this never happens again."

The corrected and voided results are from its proprietary Edison machines, which were geared toward testing blood from just a pinprick. That revolutionary idea attracted venture capitalists and lifted Theranos' value to a massive $9 billion. But the company stopped using the Edison devices in June 2015, according to the Journal.

The problems were associated with its California lab, "which has since been shut down," Buchanan said. "Our Arizona lab, that did over 90 percent of our tests, has gone through the same CMS audit and was passed. There were no major issues that were raised," Buchanan said.

The Centers for Medicare and Medicaid Services didn't immediately return a request for comment.

Asked if the voided or corrected results had been linked to health issues with patients, Buchanan said Theranos had "no indication" of any patient harm.

According to the Journal, many of the voided test results were for calcium, estrogen and testosterone levels, and it added that one corrected report was for a patient that a doctor had sent to the ER after the initial Theranos result indicated abnormally high levels. The revised report showed normal levels.