Increased CD69 expression on peripheral blood eosinophils after specific inhalation challenge.
BACKGROUND
CD69 is a molecule expressed on human eosinophils after cytokine-activation. Different studies have described the eosinophil activation, evaluated by CD69 expression, at the site of an allergic inflammation. In this study we evaluated the expression of CD69 on peripheral blood eosinophils after a specific inhalation challenge (SIC), in order to better define the state of activation of peripheral blood eosinophils after exposure to sensitizers.


METHODS
CD69 expression was evaluated by flow cytometry in nine asthmatic patients before and after a positive SIC with high or low molecular weight agents (pollens, house dust mites, Penicillia, isocyanates) and in 11 asthmatic patients who underwent an inhalation challenge with placebo. CD69 expression was evaluated at baseline, 120 min, and 240 min after the SIC or the placebo.


RESULTS
Baseline (before challenge) CD69 expression was comparable between the group of SIC positive patients and the placebo group. CD69 expression on peripheral eosinophils significantly increased 240 min after the challenge in positive SIC patients compared to placebo. In patients with a positive SIC the percentage of peripheral blood eosinophils significantly decreased at 120 and 240 min after the inhalation challenge with respect to the baseline.


CONCLUSIONS
CD69 expression on peripheral blood eosinophils is significantly increased in asthmatic patients after exposure to the sensitizing agent. These data show that the effects of a bronchial stimulation are also detectable on peripheral blood eosinophils.
Pignatti
Patrizia
P
Servizio Autonomo di Allergologia e Immunologia Clinica, Fondazione S. Maugeri, IRCCS, Istituto Scientifico di Pavia, Centro Medico di Pavia, Loc. Cravino, Via Ferrata 8, 27100 Pavia, Italy.
Perfetti
L
L
Galdi
E
E
Pozzi
V
V
Bossi
A
A
Biale
C
C
Moscato
G
G
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000096:biosynthesis* / Q000097:blood*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis* / Q000097:blood*; D001249:Asthma / Q000097:blood / Q000276:immunology; D001775:Blood Circulation / Q000276:immunology; D001798:Blood Proteins / Q000276:immunology / Q000378:metabolism; D001985:Bronchial Provocation Tests; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D005541:Forced Expiratory Volume / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D037181:Lectins, C-Type; D008297:Male; D008875:Middle Aged; D012260:Ribonucleases; D013223:Statistics as Topic; D013997:Time Factors; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D007073:Immunoglobulin E; D037181:Lectins, C-Type; D012260:Ribonucleases; D000099192:CD69 Antigens