Thanks Suev! They did that blood test on me but it was negative... as are most of my antibody tests (with the exception of a high ANA).. I have never mounted antibodies that they can measure- after vaccinations my titers were always negative as they were also after I knew I Had a virus (like chicken pox).. so most of those antibody tests don't really rule out that process for me.. The treatment as far as I know is IVIG.. so that part is good.. I just worry if i had some underlying cancer, which a lot of LEMS patients do, if I need a PET scan just to make sure?? humm.... Thank you! hope all is well!