do you think that your immune system can be so poor that it can't even create some antibodies? I don't know enough about the mechanisms that create antibodies to know if this is at all viable, but I think this might be true for my body.... Mostly because of #1 & #2... I'm think I'm forgetting some other examples, too. When I had mono in 2001, I tested negative for mono, but the doctor said that he had seen enough cases of mono to say I had it... Last Fall I had extensive allergy testing (skin prick and serum) and came up with NO allergies. I know that allergy testing is not 100% reliable, but, NO allergies with all the symptoms of allergies?? I am hypothyroid, and believe I possibly have autoimmune hypoT - but i don't have the antibodies. I have VERY weak adrenals, so that could be the root cause of my hypoT, or it could be my crap immune system or a combo of the two.