"k", I think there are several reasons AI's can fail to show up in labs. Some auto-antibodies are hard to detect because they come and go: the immune system misfires & puts out autoantiboies &/or causes general things like inflammation, then the flare recedes. So testing can be like trying to hit a moving target. Timing of labs is important. During my first appt., my rheumatologist remarked, when he saw that I had a brand-new lupus rash starting up, "Good, we're catching it 'on the rise.'"
And in some people, an AI builds steam slowly & can take years to evolve.
Also, some labs are far more proficient at running AI tests than others. Many are titer tests & are notoriously hard to perform accurately.
Another pitfall: were all necessary tests ordered? My sis assured us for 5+ years that "all her labs" were OK. Problem was, he'd never ordered thyroid tests! When he finally did, he dagnsoed her immediately with Hashimoto's thyroiditis and prescribed Synthroid. And for my first two deep-punch skin biopsies, the pathologists only performed microscopic exams of the tissue, omitting step 2, immunofluorescent stain tests, because the dermatologists hadn't ordered the stain tests.
I probably had something like 6-8 sets of AI labs done before positive results showed.
This is out of left field, but can gallbladder problems cause pancreatitis? My sister had multiple mild-ish attacks after certain foods, like peanut butter. Sis still has her gallbladder whereas my mother's was so bad she required surgery.
Do you have any vitamin deficiencies? I had a lot of twitching & neuro-like tingling when my B-12 and Folate were low as part of slow-building lupus. I think various vitamin deficiencies can cause such things. Hugs, Vee