Hi Buggie,... I'm so sorry to read that you're suffering this complication from AS, tho I suppose it's a relief to know exactly what is going on, that it isn't allergies after all you've been through... hopefully now they'll be able to provide you with a better more effective treatment.

Found 2 links with info on this:

Lung findings on high-resolution computed tomography in idiopathic ankylosing spondylitis--correlation with clinical findings, pulmonary function testing and plain radiography

and

Thoracic high resolution computed tomography in patients with ankylosing spondylitis and without respiratory symptoms

My warmest hugs to you Angie
mig