FEATURE
It ’ s a change that promises to re-shape not only laboratory processes , but also how public health laboratories both respond and innovate .
“ It ’ s a shift in mindset and it will change approaches and which LDTs you choose to bring on ,” said Kara Levinson , PhD , MPH , D ( ABMM ), director of the Tennessee Department of Health Division of Laboratory Services .
Her laboratory uses LDTs on the clinical side for infectious disease testing and in the newborn screening program . “ We ’ re part of LRN-B and LRN-C ,” she said . “ We have an environmental testing division and while we do use lab-developed tests in that division , they ’ re done in accordance with ISO 17025 standards , which are different compared to where this LDT rule impacts .”
Levinson stressed the critical role of LDTs in public health . “ I don ’ t want people to stop doing LDTs because we can ’ t stay stagnant in public health ,” she said . “ We absolutely need to continue to bring on new tests and modify tests to meet needs . We ’ re just going to have to go about it a different way based on this LDT rule .”
The Power of LDTs
Meshel Lange , MS , laboratory manager and chemical threats coordinator for the LRN-C Program at the Wisconsin State Laboratory of Hygiene ( WSLH ), oversees the laboratory ’ s Chemical Emergency Response Section . “ A significant percentage of clinical testing work done in our public health lab is LDTs ,” she said . “ As the state public health lab , WSLH utilizes LDTs to meet a variety of needs to serve the people of Wisconsin .”
LDTs are a powerful tool to help states , counties , and municipalities meet emerging public health threats . Lange cited a multi-state chemical threat event that occurred in 2018 as an example . Multiple individuals were exposed to brodifacoum ( an anticoagulant rodenticide ) via smoked synthetic marijuana products .
Healthcare professionals use vitamin K to treat brodifacoum exposure . Yet at that time , no clinical quantitative testing capability for brodifacoum exposure existed , Lange said . This left doctors without critical information to determine the appropriate vitamin K dosage for treatment .
WSLH sprang into action , standing up a new LDT in about three weeks , according to Lange .
Use of LDTs lowers test cost when compared to commercially available kits ... Using LDTs allows newborn screening programs to add screening for new disorders in a relatively rapid manner , thus alleviating the delay of waiting for FDA clearance .”
Joseph J . Orsini , PhD
“ We were the only lab in the country that had this capability at the time , and we were able to meet a multi-state need for testing to support the response ,” Lange said . “ The high degree of technical skill and capability to stand up what ’ s needed , when it ’ s needed , has been and will continue to be found within state public health laboratories and the response partnerships established throughout the country .”
LDTs have also helped expand testing for new disorders at a faster rate in newborn screening programs . Joseph J . Orsini , PhD , deputy director for the Newborn Screening ( NBS ) Program in the Wadsworth Center at the New York State Department of Health , said his laboratory has used LDTs to initiate screening for several new disorders , including Krabbe disease , Pompe disease , adrenoleukodystrophy and guanidinoacetate methyltransferase ( GAMT ) deficiency , among others . NBS also uses LDTs for amino acid / acylcarnitine testing , as well as for biotinidase and galactosemia . “ Because we are an early adopter of new tests , we have relied on LDTs to test for conditions ,” Orsini said . “ We have provided these data for evidence review and served on technical expert panels for the Advisory Committee on Heritable Disorders in Newborns and Children .”
Both Lange and Orsini noted the costeffectiveness of LDTs . “ Use of LDTs lowers test cost when compared to commercially available kits ,” Orsini said . LDTs also lower programmatic costs , which Orsini said “ allows us to evaluate and implement tests for other disorders , including newly approved tests and those under consideration for addition to the federally recommended uniform screening panel ( RUSP ). Using LDTs allows newborn screening programs to add screening for new disorders in a relatively rapid manner , thus alleviating the delay of waiting for FDA clearance .”
Orsini said New York has been able to implement LDTs before some FDA-cleared kits become available . “ Without the LDTs , the FDA-cleared kits may not have been developed ,” he said . “ I believe data generated from LDTs facilitate a manufacturer ’ s development of a test that ultimately becomes cleared by the FDA .”
LDTs also enable states to meet statutory requirements for testing for conditions within a predetermined timeframe , according to Orsini . “ Without LDTs , at least to start , states are at risk of violating their own laws ,” he said .
Lange said LDTs help ensure access to certain tests in under-served communities , such as clinical blood lead testing . Using LDTs , public health laboratories can continue to advance technology while developing costeffective testing , she said .
A Changing Process
Developing a new LDT begins with identifying a specific need , Lange said . Proposed tests go through an approval process that includes investigation development , proof of concept , methodology validation and testing of system compliance with all regulatory standards . At WSLH , a Clinical Laboratory Improvement Amendments ( CLIA ) - certified and College of American
12 LAB MATTERS Spring 2025
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