Local release of B cell-activating factor of the TNF family after segmental allergen challenge of allergic subjects.
BACKGROUND
Local production of IgA and IgE in the airways has been proposed to be an important event in both immune protection from pathogens and the pathogenesis of airway allergic diseases.


OBJECTIVE
The objective of this study was to investigate the production of B cell-activating factor of the TNF family (BAFF), an important regulator of B-cell survival and immunoglobulin class-switch recombination, in bronchoalveolar lavage (BAL) fluid after segmental allergen challenge of allergic subjects.


METHODS
Segmental allergen challenge with saline or allergen was performed in 16 adult allergic subjects. BAL was performed at both saline- and allergen-challenged sites 20 to 24 hours after challenge. Concentrations of B cell-active cytokines, including BAFF, IL-6, and IL-13, were measured by using specific ELISA and cytometric bead array assays.


RESULTS
Levels of BAFF protein were significantly increased in BAL fluid after allergen challenge (53.8 pg/mL [range, 0-407.4 pg/mL], P = .001) compared with those at saline-challenged sites (0 pg/mL [0-34.7 pg/mL]). In the BAL fluid after allergen challenge, BAFF levels were significantly correlated with absolute numbers of total cells (r = 0.779, P < .001), lymphocytes (r = 0.842, P < .001), neutrophils (r = 0.809, P < .001), and eosinophils (r = 0.621, P = .010) but did not correlate with macrophages. Normalization to albumin indicated that BAFF production occurred locally in the airways. BAFF levels were also significantly correlated with the other B cell-activating cytokines IL-6 (r = 0.875, P < .001) and IL-13 (r = 0.812, P < .001).


CONCLUSIONS
The antigen-induced production of BAFF in the airway might contribute to local class-switch recombination and immunoglobulin synthesis by B cells.
Kato
Atsushi
A
Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill, USA.
Xiao
Huiqing
H
Chustz
Regina T
RT
Liu
Mark C
MC
Schleimer
Robert P
RP
D000328:Adult; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000276:immunology*; D053264:B-Cell Activating Factor / Q000096:biosynthesis* / Q000187:drug effects / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D002452:Cell Count; D005260:Female; D006801:Humans; D017578:Immunoglobulin Class Switching / Q000276:immunology*; D007136:Immunoglobulins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D018793:Interleukin-13 / Q000096:biosynthesis / Q000276:immunology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology
D000485:Allergens; D053264:B-Cell Activating Factor; C508600:IL6 protein, human; D007136:Immunoglobulins; D018793:Interleukin-13; D015850:Interleukin-6; C505719:TNFSF13B protein, human