I think part of the problem is that this isnt a test we normally employ. A quick review of the literature shows most research articles are from the last century and the test is positive in all sorts of people without asthma and the relationship between the test and asthma is unclear.....
I wonder why the CAA have started demanding this test and how they use the results??? I ask out of ignorance as someone who manages severe asthma on a daily basis.
Sadly when you need a rare test the places you can get it done and the prices demanded become a problem. Reading up on how to do it the test seems to be worthy of well under £50
Anyone else know anything more???? What am I missing????