The most common cause of bronchiectasis is infection. Years ago before we had good antibiotics you would see this very frequently often causing the need for lobectomy (removal of the affected area of the lung). These days you just dont see it that often and certainly not to that degree because antibiotics are better. It is also seen with immunoglobulin deficiency (leads to increased risk of resp infections) so usually when the diagnosis is made, screening for this by measuring IG's is recommended. Its is also what happens with cystic fibrosis as well as in much more rare disorders such as disorders of the cilia. I've only seen the later twice in my career. (Im a pulmonologist btw). Frequently mild bronchiectasis is picked up incidentally on CT scan and doesnt have any real consequence. But, clearing mucous is extremely important with this, if its severe enough to cause excessive mucous production. Lots of ways of treating it often if its really mild nothing is needed but, I would recommend getting IG levels done if you havent already. Dont know anything specific about interferon, Id have to do some research on that. Good luck!

I was on Disease Modifying Drugs for more than seven years before becoming "Progressive," and neither I or my vast group of cohorts around the country developed a new chronic condition.

Unfortunately, just because we have one disease doesn't mean we can't get another unrelated to the first! They can be two separate things.

I don't know yet how to treat it. It seem the cough it less and less week by week, i'm still hoping it will go away all together.

Sorry for being late about this ...But the final answer is...
When I saw the Hematologist / Oncologist for a consult about the low IGg levels, he gave me this answer.
When a person has MS thier immune system is not working properly such as having an elevated T cell production, and the T cells being part of the immune system. When you have one part of the immune system that is elevated(T cells) you are most likely to have another area that is lowered (the IGg),
The Doctor explained that the entire immune system is like a balancing act.
In order to bring the IGg levels up, there would be more testing and monthly infusions, which are very expensive, as there was nothing to correct the issue since the problem was the autoimmune disease itself (MS).
The best way to deal with this is to see my primary doctor at the first sign of a illness, get my flu shots and stay away from sick people.

Ok .....heres an update to all who are interested. I got the IGg test done and 2 of the sub-classes were deficient the pulmonologist referred me on to a oncologist, I declined this initially in order to talk to my neurologist because i wanted his opinion due to taking the betaseron he said that he has never encountered a deficient IGg level ever due to use of this drug but wanted to confer with a doctor from the drug company that mades the drug, and the answer that i got was the betaseron will not cause a deficient IGg level. So off to the oncologist I go.