The late asthmatic response is associated with baseline allergen-specific proliferative responsiveness of peripheral T lymphocytes in vitro and serum interleukin-5.
BACKGROUND
Increasing insights into the mechanism underlying the allergen-induced late asthmatic response (LAR) have been gained with implication of activated eosinophils and CD4+ T lymphocytes. However, the patient characteristics that indicate the individual capacity to develop a LAR are not well-defined.


METHODS
In 22 subjects with mild to moderate house dust mite-allergic asthma, we investigated the relationship between the LAR and two other models of late-phase allergic inflammation, i.e. the allergen-specific proliferative response of peripheral blood T lymphocytes in vitro and the late cutaneous response. Non-specific bronchial responsiveness (PC20histamine), lung function (FEV1), peripheral blood eosinophil count, early phase allergic skin sensitivity, and levels of total and specific immunoglobulin E (IgE) were determined prior to bronchial allergen challenge. Serum levels of interleukin-5 (IL-5) were measured before and at several time points after allergen inhalation.


RESULTS
A significant correlation was found between the magnitude of the LAR and the allergen-specific proliferative response of peripheral T lymphocytes (r = 0.44, P = 0.04) but not the late cutaneous response. Stepwise-multiple linear regression of the magnitude of the LAR on the parameters analysed at baseline, resulted in a model combining PC20 histamine, early phase allergic skin sensitivity, and the allergen-specific proliferative response of peripheral T lymphocytes (R2 = 0.84, P<0.001). No contribution of the late cutaneous response to the prediction of the LAR was found. Serum levels of IL-5 increased significantly at 6 h (P = 0.01) and 24 h (P = 0.003) after bronchial allergen challenge and correlated with the allergen-specific proliferative response of peripheral T lymphocytes in vitro (rho = 0.48, P = 0.02).


CONCLUSIONS
The findings in this study point to a role of TH2-lymphocyte responses in the development of the allergen-induced LAR. In allergic asthmatic patients, allergen-specific responsiveness of peripheral T-lymphocytes in vitro may serve as a model to determine the individual capacity to develop a LAR after allergen inhalation.
Department of Pulmonology, Academic Medical Center, University of Amsterdam, The Netherlands.
M J
MJ
van der Veen
R J
RJ
Van Neerven
E C
EC
De Jong
R C
RC
Aalberse
H M
HM
Jansen
J S
JS
van der Zee
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D039741:Antigens, Dermatophagoides; D001249:Asthma / Q000276:immunology*; D001985:Bronchial Provocation Tests; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006632:Histamine; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D015848:Interleukin-5 / Q000097:blood; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D008925:Mites / Q000276:immunology*; D012867:Skin / Q000276:immunology; D012882:Skin Tests; D013601:T-Lymphocytes / Q000276:immunology*
D000485:Allergens; D039741:Antigens, Dermatophagoides; D006023:Glycoproteins; D015848:Interleukin-5; D007073:Immunoglobulin E; D006632:Histamine