If you do not have an "active" A/I condition, the lack of antibodies in your blood circulation will return mostly negative results in any relevant blood testing.
There are cases where also healthy individuals would
have positive ANAs titres (antinuclear antibodies- used to test for A/I disorders) but usually in the lower ranges.
If you're really concerned three things you can do:
Optimize your lifestyle through proper diet (avoid wheat and too many carbs), exercise daily, stay hydrated by drinking ample spring water, do "oil pulling" every morning, meditate, do yoga, improve your breathing ( go to the normalbreathing website for details), no tobacco, limited alcohol (preferably just the occasional glass of red wine) and so on.
2. Hippocrates — "Let food be thy medicine and medicine be thy food."
Choose (carefully) natural supplements and nutritionally dense foods of highest quality possible (organic/fresh/unprocessed).
3. Consider genetic testing.
There are many gene mutations, where Epigenetics
(modification of gene expression to affect how cells read the genes) can often make a profound difference in disease prevention and treatment.
I hope this helps,