In this era of biologic asthma medications, like Mepolizumab(Nucala), Benralizumab(Fasenra), Dupilumab(Dupixent), Reslizumab(Cinqair)and others, terms like “E” asthma or “Eosinophilic Asthma” pop up a lot.
Eosinophils are a type of white blood cells, that when activated by common triggers such as pollen, mold, dust and dander, can cause inflammation leading to severe and chronic asthma symptoms. Appx 5-10 % of people who suffer from asthma, have a severe form of disease. For those who fall in that category, its estimated that more than 60% have elevated levels of Eosinophils in their airways.
Well, it got me thinking about my own asthma. Early in life I definitely fit into the “E” category of asthma. I can vividly recall an instance at the age of 24, where blood tests taken during a hospital stay for a severe asthma exacerbation, revealed an absolute eosinophil count of over 1500 or 15%! That’s pretty high. The normal range is generally 100-400 (1-4%). This was back in the late 1970’s, but even then I remember the Pulmonologist telling me that a high eosinophil count was the hallmark of severe allergic asthma and that I would probably have to stay on steroids the rest of my life to control them.
Ah, but that was more than 40 years ago. In more recent times that hasn’t been the case. Now every time I meet with my Pulmonologist to discuss new treatment strategies, he looks at my labs and says…”You don’t have any eosinophils, so a biologic probably wouldn’t work on you”. Indeed, in reviewing my online labs records dating back more than 20 years, he’s right. My blood eosin levels have either been really low or non existent. This must certainly mean that I have non-eosinophilic, or non-Th2 type asthma, right?
BUT HOLD ON A SECOND… Its also a fact that steroids can wipe out eosinophils. And most, if not all of the eosinophil measurements done on me over the past 2 decades were done while I was hospitalized and receiving high-dose steroids. On top of that, I’ve been on and off steroids (mostly on) for 50+ years, so isn’t it possible that my eosinophils have just been suppressed or hiding? I wonder what my eosin count would be if I weren’t on steroids?
Well now’s probably good time to find out, because for the last 16 days I’ve been completely off prednisone… the longest I’ve been off them in over a year. My Immunologist who believes my asthma is too severe not to have eosinophils, agrees with me that we should take advantage of this steroid pause, by checking my eosin levels every couple of weeks and see if those little devils start appearing again.
Nobody really knows how long you have to be steroid free for eosinophils to start showing up again in your blood. But, assuming I can go that long, 2-3 months seems like a sufficient amount of time for this to happen, if its going to. And while high the presence of eosinophils in one’s sputum or airway is much more accurate in diagnosing “E” asthma, blood eosin levels serve as a pretty reliable surrogate marker.
Whether or not my eosinophils levels will reach the higher range remains to be seen. But, if yesterday’s tests results (below) are any indication, and the trend line continues, it would appear that I do indeed have eosinophilic or “E” asthma after all. Regardless of what we find, after living with such complex airway disease for so long, I’m just happy that we might be able to finally rule in or out with some certainty, which type of asthma I actually have.
If the verdict is that I indeed have “E” asthma, at least I have some treatment options that I didn’t have before. Namely, biologic meds like the ones I mentioned above. If the verdict is that I don’t have “E” asthma, then nothing lost except a few extra blood draws.