By: Jess Aloe

Lab directors of major medical centers across the nation have written a letter against proposed federal regulation of so-called LDTs – the custom made laboratory developed tests frequently used by doctors to help diagnose everything from cancer to birth defects to Lyme disease.

 Twenty-three laboratory directors, from institutions such as Harvard, Yale, Stanford and the Mayo Clinic, signed a letter July 16 urging Obama administration officials not to release Food and Drug Administration draft recommendations that would spell out how diagnostic tests for medical conditions might be regulated in the future.

While many diagnostic tests on the market undergo U.S. Food and Drug Administration review, thousands of others do not because they take advantage of an exemption in FDA regulations that frees them from having to prove that their tests correctly diagnose the disease.  In 2010, the FDA announced its intention to regulate at least some of the tests, but has been met with opposition by many clinical labs.

“FDA regulation of LDTs would be contrary to the public health,” states the letter addressed to Brian Deese, acting director of the Office of Management and Budget.   “Numerous critical tests are only available as LDTs, including many ‘gold standard’ DNA sequencing assays, newborn screening tests, and tests for rare diseases.”

The group argued that the tests are already highly regulated. In addition, they also said the tests are services – not devices – and therefore are not subject to FDA oversight.

The  letter  comes two weeks after Sen. Edward J. Markey and other lawmakers urged the OMBto release the draft recommendations, called guidance, because some tests on the market may be misdiagnosing patients.

The laboratory directors’ letter also pointed out that the FDA process is slow, and would not adequately respond to the needs of small patient populations, or to quickly develop tests for emerging infectious diseases such as was done SARS or H1N1.

The New England Center for Investigative Reporting recently reported on labs using tests that have not been approvedby the FDA to diagnose Lyme disease. In Markey's letter to OMB, he specifically referenced an LDT frequently used to detect Lyme, which was reviewed by the Centers for Disease Control and found it to be seriously flawed. 

OMB did not immediately respond to a request for comment.