[anabanana]

Hello,

Quest uses EIA on neuropathy antibody testing, while Athena uses ELISA.

On some Neuro. Antibody tests, it says Athena does both , ELISA and WESTERN BLOT (re-confirming). Does it mean the ELISA has to be positive for the WESTERN BLOT to be run, or are these 2 methods run at the same time and then compare results?

It does not say that Quest runs more than EIA on most tests, do they run western blot also if EIA is positive?

ELISA or EIA better, no difference?

Any insight anyone?
Ana

[glenntaj]

--run the ELISA test first for a number of infectious conditions, and the run a Western Blot if there are suspicious results from the ELISA. This is mainly due to cost concerns more than anything else.

The ELISA (enzyme-linked immunoabsorbent assay) is a subtype of the overall EIA (enzyme linked immunoassay) that is generally used on liquid samples (such as serum).

I prefer the Western Blot myself, as it is more sensitive for a lot of antigens.

There is also the possibility of using a PCR (polymerase chain reaction) test to more directly test for the presence of an infectious agent, but this involves an attempt to culture the agent and takes more time (and is therefore even more expensive).

[anabanana]

[QUOTE=glenntaj;896467]--run the ELISA test first for a number of infectious conditions, and the run a Western Blot if there are suspicious results from the ELISA. This is mainly due to cost concerns more than anything else.

Hi Glen, I was more wondering if there is an order to the methods: ELISA positive, then WESTERN BLOT. or Are both these tests run concurrently?
The ELISA (enzyme-linked immunoabsorbent assay) is a subtype of the overall EIA (enzyme linked immunoassay) that is generally used on liquid samples (such as serum).

I was meaning the ELISA vs EIA(agglutination assay-QUEST) for the neuropathy antibody tests. It seems that the EIA(agglutination assay-QUEST), which was developed by DR Latov, is cheaper and quicker to perform, but is it necessarily as good as the ELISA(more time consuming, intensive stepwise process)?

One study (on pubmed), ran the EIA(agglutination assay-QUEST) of GM-1 antibody AFTER the Guill-Barr patients already had a positive(high/low titers) ELISA(original method, time consuming, more expensive process) antibodies run. The results were:

Patients with High titers on ELISA also tested High on the EIA (QUEST); however, the patients that had Low titers on ELISA tested "absent or weak" on the EIA. It concluded: The sensitivity of our agglutination assay(EIA-QUEST) was much lower than that of ELISA.

I prefer the Western Blot myself, as it is more sensitive for a lot of antibodies.

Are you saying that the western blot can be run first, without running ELISA and give answers without using ELISA?
My understanding from what is online anyway, it tends to be the process to run ELISA first, then run WESTERN BLOT if the ELISA is positive?
What are your thoughts, experience on this?

Thanks!
Ana

[glenntaj]

--that generally, if an ELISA is positive for antigens, then a western Blot will be performed for confirmation.

The agglutination assays are very specific tests, designed to show autoantibody activity to peripheral nerve--but you are right in that they tend to be more sensitive than specific. During the acute phase of my neuropathic attack I had a series of ELISA's run through Quest for autoantibodies to peripheral nerve, and all turned out negative (so no Western Blots were done--though I did have some Western blots done for other things, such as Lyme and West Nile virus, while possible causes ere being investigated, even though initial ELISA tests on these were negative--so were the Western blots). However, Dr. Latov's own lab at the Cornell Weill Center for Peripheral Neuropathy ran his own ganglioside agglutinin test on me (EIA) and came back with a slight positive. It was speculated at the time that this might have been picking up autoantibody activity that was unique to me, but which would not fall into any of the categories that Quest tested for. It is theorized that in acute onset and some longer term "idiopathic" small fiber neuropathies autoimmune molecular mimicry processes are at work, and that these may be very individual--and that we have not yet recognized what antigens are being attacked yet. (I am reminded that even the antibodies Latov lists and that Quest tests for have only been known about for around two/three decades.)

[anabanana]

Originally Posted by glenntaj

--that generally, if an ELISA is positive for antigens, then a western Blot will be performed for confirmation.

The agglutination assays are very specific tests, designed to show autoantibody activity to peripheral nerve--but you are right in that they tend to be more sensitive than specific. During the acute phase of my neuropathic attack I had a series of ELISA's run through Quest for autoantibodies to peripheral nerve, and all turned out negative (so no Western Blots were done--though I did have some Western blots done for other things, such as Lyme and West Nile virus, while possible causes ere being investigated, even though initial ELISA tests on these were negative--so were the Western blots). However, Dr. Latov's own lab at the Cornell Weill Center for Peripheral Neuropathy ran his own ganglioside agglutinin test on me (EIA) and came back with a slight positive. It was speculated at the time that this might have been picking up autoantibody activity that was unique to me, but which would not fall into any of the categories that Quest tested for. It is theorized that in acute onset and some longer term "idiopathic" small fiber neuropathies autoimmune molecular mimicry processes are at work, and that these may be very individual--and that we have not yet recognized what antigens are being attacked yet. (I am reminded that even the antibodies Latov lists and that Quest tests for have only been known about for around two/three decades.)

Hi Glen,
I appreciate your detailed response! Hope you take no offense if I correct something you said, just that it's relevant to know this fact in context of testing: QUEST doesn't run the original ELISA(time consuming, more expensive), they run the EIA version (Latovs ganglioside agglutinin test I believe, quicker, cheaper). The only thing I could find on the QUEST website is stating in general terms: That the ELISA has more sensitivity than the EIA. It's interesting that they would point this out, as the neuropathy tests they run are EIA based, not ELISA. I know these methods share similarities, but are performed slightly differently, ELISA being more work, more time, more cost.

I'm conflicted whether to run the cheaper EIA at QUEST(Latovs test), or the Athena method (using ELISA). Studies showed that EIA was less sensitive to low titers, so I'm concerned. I wish more people would chime in

Cheers!

[glenntaj]

--back when I had all these done, in 2003-2004, the specific nerve antibody tests--for the GD, GQ, anti-sulfatide, etc., antigens--were all ELISA (says so right on the test results page, all of which I have). I had the less specific ganglioside agglutinin test for gross autoantibody activity at Latov's office--that's the one I had the mild positive on.

It is possible this may have changed (again, I would think, due to cost considerations).