Laboratory Developed Tests

[Mabel Adams]

Someone online said that anything not in an FDA-approved kit or reagent system purchased from a vendor is a lab developed test and thus subject to the new FDA rules, including all those ancient procedures that are in the methods section of the Technical Manual. I could argue that the titer procedure is really just specimen treatment, not a test different from any other tube AHG test.  Generally, the tube AHG tests are defined in the manufacturer's instructions.  Is saline replacement a test?  I wonder what the Lab regulatory bodies will say about the new rule in regard to BB tests.  Anyone have any extra knowledge about this for BB?

[Neil Blumberg]

I think most blood bank reagents and tests have been grandparented in.  The FDA knows there is no alternative to these home brew reagents and testing procdures.

[Arno]

2024-08935.pdf (federalregister.gov) 

I have not read it all but some BB tests seem to be out of scope such as the use of rare antisera/red blood cells when no reagent is commercially available as well adsorption techniques, Donath Landsteiner test, Drug Induced hemolysis tests and the Monocyte Monolayer Assay... not an exhaustive list but I might have missed while going though quickly these 500+ pages. 

[BankerGirl]

1 hour ago, Neil Blumberg said:

I think most blood bank reagents and tests have been grandparented in.  The FDA knows there is no alternative to these home brew reagents and testing procdures.

I attended a webinar presentation on this and the presenter stated specifically that NOTHING has been grandfathered.  There are some items that the FDA has said it would still use enforcement discretion, but was very much above my understanding.

 

[Neil Blumberg]

"the presenter stated specifically that NOTHING has been grandfathered. "

I think the presenter is mistaken.  The FDA specifically noted that the area of rare reagents and cells, and similar testing would not be subject to LDT enforcement.  Of course, all the opinions in the world matter not a bit until the FDA actually acts or does not act.  I cannot imagine they want to be inspecting every tertiary care hospital and blood center reference laboratory for this purpose.  And most of the things we are discussing in the transfusion service and immunohematology lab are not used to provide diagnostic results to practitioners,  but rather used for internal resolution of therapeutic decisions. Quite different from your average laboratory test which provides quantitative or semi-quantitative result to physicians and other practitioners who make decisions based upon lab results.  Perhaps a nuance, but a real difference.  If the FDA insists we validate the use of a potent anti-HPA1 anti-platelet antibody in our decision making, we're out of luck :).  Ain't happening.

Interestingly, much of what we do in clinical medicine has not been "validated" or subjected to FDA-like regulation.  Such as using autologous or allogeneic stem cell transplants, liver transplants, using a stethoscope or looking at a patient's retina with an ophthalmoscope.  No validation.  No data to speak of at all.

[Tynuvm]

Does anyone know, if laboratory made antisera (i.e. spike diluent with known commercial antisera), would be considered a LDT if used as a quality control of antibody screening cells? 

[Neil Blumberg]

I believe internal QC or non-patient testing is not covered by the FDA regs.  Only tests used to report patient results.

[pinktoptube]

I believe most of these tests will fall under 1976-Type LDTs which fall under enforcement discretion. The immunohematology tests that may fall the new rule would be modifications to manufacturers' instructions (i.e., you use the reagent/test in another method, you use a different specimen type or extend the specimen acceptable time limit). 

[Mabel Adams]

With the Supreme Court decision is all of this moot?  Is the FDA still able to regulate LDTs since congress didn't specifically address this?

[Neil Blumberg]

Your guess is as good as anyone else's. . I suspect the FDA will continue doing regulatory stuff until told to stop by Congress or some court.  I'd assume they will regulate LDTs as they have proposed.