My immune (blood ) system shows perfectly fine. However, my lungs are shot. With each and every bacteria infection I get in my lungs, it does more and more damage. I eat healthy as well but it doesn't help with picking up these environmental bacteria if you have lung damage. MAC can colonize in your lungs. It goes dormant and then will kick up its ugly little head at the most inopportune time. However, by taking Azithomyzin 500 mg 3x per week I have not had it reappear since 2017. I have picked up many other environmental bacteria since then though. So many I finally quit asking what I had for a period of time. I do the sputum sample thing when I know I am sick , they tell me what to take, and I take it. I am back to asking again at this point.