coughing with green phlemg for nearly a year what could be going on?

I developed a cough with green phlemg last early August my GP thought it was a thing going around and treated me with antibiotics , however it's never cleared up .  I do have asthma and lupus.After a winter and spring of being on and off antibiotics a visit to a ENT and pulmonary Dr. We can't get it to clear up.  In april I developed pneumonia which did resolve but the cough & green stuff has continued. I have been on all the normal protocal for sinuitis nasal washes etc.  I take a lot of meds due to lupus.  My Rheumy thinks mayby it could be my lupus and is considering a plan of 40mg pred and 2.5 mg metotrexate 3 tabs weekly. I am very sensitive to pred and blow up fast so I am leary of doing this. I'm currently in the middle of a 30 d Zithromyacin 250 mg course and at first things were good and a few days ago it came back.  I'm continuing it but wonder what to do next any suggestions or thought on what could be wrong?  any help greatly appreciated.  I take celebrex, plaquenile, advair 250/50, combivent, singular , loratadine, normadyne 200mg and norvasc 5mg for HBP.

[National Jewish]

Green phlegm usually, although not always, indicates infection.  This phlegm could be coming from your sinuses and/or your lungs.  It would be unrelated to your lupus.  It may be a sign of a non-infectious, hypersensitivity or allergic problem such as allergic bronchopulmonary aspergillosis (ABPA).

To find out what could be wrong your phlegm needs to be carefully examined, both under a microscope and by culture.  It should be cultured for bacteria, fungi and mycobacteria.  A CT scan of your chest may show if there is another problem effecting your lungs.