I agree with you....falsely negative bloodwork is very common in MANY autoimmune diseases, if not all of them!
The bloodwork and intestinal biopsies done to diagnose celiac disease are notorious for false negatives, for example. I myself am seronegative for rheumatoid arthritis, but you can see the damage in the joints in my hands and feet on xrays and I'm developing rheumatoid arthritis nodules on my fingers. All of my rheumies have agreed that I do have RA, despite the negative bloodwork.
The problem with autoimmune disease is that the doctors always test for certain well-known types of antibodies. But what if you are one of the (sometimes significant) percentage of people whose body makes a more exotic type of antibody that is NOT tested for? In other words, a "custom" antibody peculiar to you...or at least, not one of those tested for. Even though I'm not a microbiologist, I've been told by microbiologists that this is possible.
What if you are on immunosuppressants (like prednisone or Imuran) when you have the blood work done? Those meds suppress the formation of antibodies so if you're not making any that means your meds are doing their job! Of course your bloodwork will be negative in these cases!
Which should mean that your doctor will try to diagnose you a different way, without the bloodwork. Unless he or she is a doctor like the one you encountered...and there are far too many doctors like that out there. I'm so sorry you had to run into one of them!!
Are you able to see someone else for a second opinion?? You might want to carry copies of all your previous medical records with you to the appt if you are able to get one with a different doctor!
Lyme Disease, AIH, Hashimoto's, "lupus-like" CTD?, fibro, RA, celiac disease, asthma, psoriasis, Raynaud's, hypertension, osteopenia, sleep apnea, RLS, GERD, degenerative disc disease, cubital tunnel, tarsal tunnel, Doxycycline, Prednisone, Imuran, Plaquenil, Lyrica, Cymbalta, Levothyroxine, Atenolol, Cozaar, Zyrtec, Fosamax, Albuterol, Prilosec, CPAP, Darvon, Morphine Sulfateautoimmunediseasesgfliving.blogspot.com