In addition to checking for autoimmune thyroid disease, I would recommend you see an immunologist to check for immune deficiency because of the MAC. Paradoxically, one can have autoimmune disease and immune deficiency both. Excess antibodies against your own body cells but insufficient antibodies against germs. I have lupus plus 4 other AI diseases plus immune deficiency. Your pulmonologist might be able to check a screening test for the deficiency ( immunoglobulins IGG IGM IGA). Immune deficiency can be treated also if you’re prone to infections and antibody levels are low enough.
When I was first diagnosed with lupus, my ANA was 1:40 and no other tests were positive but I had had numerous symptoms and signs of lupus for a decade.