I have been on MTX for 3 months and doing well. I also have bronchiectasis as a result of lung damage from whooping cough when I was 3 years old and had a partial lobectomy (part of lung removed ) when I was 16. I am now 63. I have a productive cough all the time but how would I know the difference from my normal cough and a MTX related cough. Anyone had this problem?