EOSINOPHIL ACTIVITY REFLECTS CLINICAL STATUS IN PATIENTS WITH ASTHMA BEFORE AND DURING A PREDNISOLONE COURSE

Background: Both overtreating and undertreating asthma can be harmful, either because of side effects or development of uncontrolled asthma. As the eosinophil granulocyte is of importance in asthma, it is logic al to study this cell in the search for a marker for the right level o f treatment. Objective: To study the changes in eosinophil activity an d the correlation to clinical status in asthmatic patients who have de teriorated and during prednisolone treatment. Methods: Nine patients w ere studied on two occasions: with exacerbation (visit 1) and during p rednisolone treatment (visit 2). Clinical evaluation was performed as well as analysis of percentage of eosinophils, eosinophilic cationic p rotein (S-ECP) in serum and expression of intracellular ECP, measured by cell flow cytometry using a monoclonal antibody (EG2) against the a ctivated form of ECP. Results: Visit 1: four patients had eosinophils above normal, mean 6.5%, range 1.5 to 13.8. S-ECP was measured in seve n patients of whom five had values above normal (16 mu g/L), mean 29.5 , range 1.5 to 13.8. Intracellular expression of ECP was above normal (mean 26.7 +/- 10.8) in seven out of nine (mean 48.1, range 28.8 to 69 .6). Visit 2: all patients improved and all eosinophil parameters decr eased. The eosinophil concentration fell to a mean of 3.0%, range 1.0 to 6.6, S-ECP to a mean of 10.5 mu g/L, range 3.2 to 17 and intracellu lar expression of ECP to a mean of 33.4, range 19.4 to 40.9. Conclusio ns: Reduction in eosinophil activity followed improvement in clinical condition. Measuring intracellular expression of ECP may be of value i n addition to eosinophil count and S-ECP in monitoring asthma.