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.)