- Immune response to bacterial antigens in pediatric atopic asthma patients

CONSTANZA OTERO; R. PAZ; N. GALASSI; A. TEPER; M. KOHAN; L. BEZRODNIK; S. GOLDSTEIN DE FINK; M. FINIASZ

Berlín, Alemania

Congreso; 2nd European Immunology Congress; 2009

European Federation of Immunology Societies

In Argentina more than three million people suffer from asthma, and the number is rising. Asthma is defined as a disorder characterized by chronic airways inflammation that results in high mucus production and airways hyperresponsiveness. A Th2 mediated immune response prevails in these patients. In the asthmatic exacerbation period, Crisis (Cr), triggered by viral infections or other factors, there is a high prevalence of bacterial overinfection. Our objective is to compare immunological parameters and in vitro response of lymphocytes to bacterial antigens in the same patient, at that moment and at a time of stability between episodes (I) . We studied 12 asthmatic patients both at Cr and I. We evaluated Eosinophils, Basophils and IgE expressing B lymphocytes; as well as T regulatory cells (by expression of CD4 and CD25 high (Treg)), that might inhibit the development of a Th2 response, together with ãäT cells, which function in asthma is not completely understood, but could have a role in the increased airway responsiveness. To evaluate the T cell response, mononuclear cells were cultured for 48 hours in the presence of M. tuberculosis (M) or S. pneumoniae (Spn), or absence of them (C). Then the percentage of activated cells was determined (Expression of CD69 or CD25 at 48 hours). All the parameters were evaluated in peripheral blood by Flow Cytometry. Results: % mean  + SEM. Eo: Cr 5,7+1,4; I: 7,4+ 1,1; Ba: Cr: 0,2+0,04; I: 0,4+0,1; BIgE: Cr: 8,9+1,5; I: 8,4+1,5. Treg: Cr: 2,2+0,5; I: 1,7+0,5. ãäT: Cr: 3,2+0,6; I: 3,0+0,5. CD69: Cr: C 6,0+1,6; M 13,5+3,1; Spn 10,1+2,8; I: C 7,8+2,3; M 15,3+2,7; Spn 10,7+2,0. CD25: Cr: C 9,1+1,1; M 10,0+1,1; Spn 9,3+0,9; I: C 9,7+1,0; M 12,6+0,9; Spn 11,4+1,1. Discussion: Even though the pathophysiological characteristics of asthmatic patients in periods of Cr and I are different, no significant differences were observed in the parameters (cell populations and cell response to bacterial antigens) evaluated when compared for the same patient at Cr and I. We might be able to detect differences if we studied cells from the lungs, the target organ.