Theranos Ignored Red Flags On Its Blood Clot Tests

Beleaguered laboratory company Theranos sent out unreliable blood clot tests on at least 81 patients, according to an article by John Carreyrou and Christopher Weaver in the Wall Street Journal.

Theranos, a former darling of Wall Street, Silicon Valley, and high technology medicine enthusiasts, has been the subject of a series of embarrassing revelations in the Wall Street Journal. The new report is the first containing information with specific information suggesting that patients taking warfarin may have received inaccurate test results used to monitor and adjust their therapy.

Carreyrou and Weaver report that an inspector from the Centers for Medicare and Medicaid Services (CMS) found “deficient practices” in five separate categories of lab tests. The greatest concern was with the hematology tests, which the inspectors said “posed ‘immediate jeopardy to patient health and safety’.”

The prothrombin time (PT) tests were not performed on Theranos’ proprietary (and also highly controversial) lab equipment. Instead the tests were performed on standard equipment manufactured by Siemens AG. The CMS inspection found that the lab sent out results despite multiple failures in its quality control system. “Labels for Siemens prothrombin time testing products recommend that labs that see aberrant quality-control results refrain from reporting patient data until documenting and correcting possible problems,” the WSJ writes. “At Theranos, there were seven quality-control failures in a single day.”

I asked Robert L. Michel, Editor-in-Chief of The Dark Report, an intelligence service covering the clinical laboratory industry, how often these kind of problems occur in the lab industry. “The reality is that we don’t know,” said Michel. “Because of the way CMS handles CLIA inspections of medical laboratories, the scale and scope of lab testing errors that may affect patient safety or put patients at risk is unknown. This is because CMS does not make public the results of all CLIA inspections for those labs that it regulates.”

Theranos said that it has “no reason to believe that these issues have affected patients’ health.”  It said it had “notified any potentially affected patients.”

Lab results should be “accurate and reproducible,” said Michel. PT tests in particular are particularly sensitive, since they are used to guide warfarin dosage. Too much anticoagulation can produce serious bleeding complications; too little anticoagulation can lead to heart attacks or stroke.

Theranos also used expired reagents in some of its PT tests, according to the WSJ. Further, the “lab’s director didn’t have responsibility for the lab’s quality-control program and the lab’s quality-control manager was unqualified.” The company has now hired a new director of the lab in California where the problems occurred.

“It is alarming that a company committed to patient care would knowingly send out questionable lab results. An accurate PT/INR is essential to patients taking warfarin,” said Beth Waldron,  an anticoagulation expert who co-founded a thrombosis education program at the University of North Carolina in Chapel Hill. Waldron is also a patient who used to take warfarin. “Anticoagulants are the most common medication to cause adverse events for good reason. Too little drug in the body can cause clotting while too much can cause bleeding and both these extremes bring potentially fatal consequences. Warfarin is a finicky drug which requires daily vigilance by patients like myself to ensure a good outcome. The anticoagulant effect of warfarin is highly influenced by diet, lifestyle and concomitant medications. This is why the PT/INR test is so vital…it tells us how we’re doing given all these influences, at staying within the optimal blood thinning target range and it guides our dosage adjustments accordingly.”



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