The Food and Drug Administration and the Centers for Disease Control and Prevention said some blood tests have underestimated lead levels in children and adults. (Andrew Harnik/Associated Press)

Federal officials are warning that some blood tests may have “significantly” underestimated lead levels, and they are urging the retesting of some children, as well as pregnant and breast-feeding women.

The Food and Drug Administration and the Centers for Disease Control and Prevention said the tests in question were made by Magellan Diagnostics, a Massachusetts-based testing company whose products are used in laboratories and doctors' offices throughout the country. The problem may go as far back as 2014, the agency said. The warning applies only to tests in which blood samples are taken from a vein, not the more common, less invasive tests in which fingers or heels are pricked for a blood sample.

In a conference call with reporters, Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, said the agency's investigation was in its early phases, and that most people probably won't be affected. Still, he said, he was deeply concerned about the inaccurate results and that a “root cause” hasn't been identified.

The FDA and the CDC recommended that children younger than 6 be rechecked if their Magellan venous tests showed lead levels of less than 10 micrograms per deciliter. The agencies also said women who are pregnant or nursing should get retested, while other adults worried about lead exposure should talk to their doctors about possible repeat tests.

Each year, about 300,000 venous blood tests are performed in laboratories using Magellan technology, while more than 2.5 million tests are conducted in physicians' offices, typically using a finger or heel stick, said John Kraeutler, chief executive officer of Meridian Bioscience, Inc., which owns Magellan. He said Magellan is working closely with the FDA to resolve the situation, and is offering to move customers to finger-stick testing from vein-based testing.

Shuren said that Magellan got complaints about inaccurate results involving one of its testing systems in 2014, but that the company concluded “the risks were negligible” and that the problem could be fixed by delaying blood processing for 24 hours. Magellan submitted a malfunction report to the FDA in 2015, agency officials said, but they added they believe the company underestimated the risks involved by characterizing the situation as “not likely to cause adverse health consequences.”

Shuren said the FDA became concerned about the problem in April 2017, when the company requested changes to a device's label. (In clearing devices, the agency requires firms to demonstrate that the devices are at least as safe and effective — substantially equivalent — to one already on the market. In the case of diagnostics like blood tests, companies also must demonstrate that the tests are accurate and reliable.)

Patrick Breysse, director of the CDC's National Center for Environmental Health, noted that the agency has kept a close eye on communities like Flint, Mich., where the water was contaminated by lead. He estimated that “less than 1 percent” of children in Flint might be at risk for having lead levels that were inaccurately reported.  

Tim Hill, an official with the Centers for Medicare and Medicaid Services, said that Medicaid would pay for the retesting of children on the program and that people covered by private insurance should ask their health plan about retesting.

Typically, lead testing, especially for children, is done by a finger or heel stick known as a capillary test. If the results show elevated lead levels, the results are confirmed through a venous test.

“There is no safe level of lead exposure for children, and the best 'treatment' for lead poisoning is to prevent lead exposure before it happens,” said Jennifer Lowry, chair of the American Academy of Pediatrics Council on Environmental Health.

The CDC said that 4 million households have children that are exposed to high levels of lead, which can impair cognitive abilities and cause other damage.

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