Common Lead Test Can Give False Results, FDA Warns

Posted May 18, 2017

The U.S. Food and Drug Administration and Centers for Disease Control and Prevention are warning Americans that certain lead tests manufactured by Magellan Diagnostics may provide inaccurate results for some children and adults in the United States.

Because of these inaccuracies, the CDC recommended that healthcare professionals re-test children under 6 years of age as of May 17, 2017 who had a venous blood test result of less than 10 µg/dL using the Magellan testing system.

The blood tests were made by Magellan Diagnostics and it's the only FDA-approved test used in most doctor's offices, the FDA said. They added that now pregnant women and nursing mothers who had a venous blood draw with this system should also be re-tested. "The AAP will work with our pediatrician members to provide those families impacted by today's warning with the resources and guidance they need to protect their children from lead exposure", said Fernando Stein, MD, FAAP, president of the AAP.

Patrick Breysse, director of the CDC's National Center for Environmental Health, said that the CDC is keeping a close eye on communities like Flint, Michigan, where lead has contaminated the water.

Pregnant or lactating women who had one of these tests also should be retested.

A blood test is the only way to know if a child has too much lead in his or her body. The FDA believes this error may date back to 2014.

The FDA indicated that all four of Magellan Diagnostic's lead testing systems - LeadCare II, LeadCare, LeadCare Ultra, and LeadCare Plus - may have provided faulty results by performing tests on vein-drawn blood.

FDA's diagnostic review team first learned of the potentially inaccurate results when reviewing a 510 (k) submission for a new version of the LeadCare system earlier this year, Shuren said.

On November 4, 2016, Magellan notified its customers of a similar problem when processing venous blood samples taken with their LeadCare II testing systems, and by November 11 they notified customers by bulletin that the rubber caps of some of the blood collection tubes may introduce a substance into the blood sample when used with the LeadCare II systems.

The agency "did not feel that the data was either adequate regarding what they thought may have been the cause of the problem, the extent of the problem or the effectiveness of the mitigation they put in place", the FDA's Shuren said. While no level is considered safe, the federal safety limit is half that level. Lead can impair cognitive abilities and cause other damage in children.

The government officials noted that lead exposure can cause damage in almost every system in the body and produces no symptoms.

Officials say they understand that people affected by this issue are going to be concerned about their health, and note that while most children likely received an accurate test result, it is important to identify any whose exposure may have been missed or underestimated.