Welcome James. I have had many stem cell treatments. I also have COPD. At this point, I believe that all that has been accomplished was to tone down inflammation. I think that the answer will be in a treatment that combines stem cells with other therapies, not just stem cell treatment alone.
Be very careful of clinics that offer little or no evidence of safety or efficacy. They boast that their treatment is unique, better than anyone else's, but offer no more than a sales pitch and a few testimonials. There are numerous posts on here about other red flags to watch for. Clinics are popping up all over and the name of the game for far too many of them is not regenerating our lungs, but generating cash for their coffers.
The Ask the Doctor section is a good place to read about several clinics. Almost every host has been asked questions on treating COPD.