RT Journal Article
SR Electronic
T1 Nerve growth factor levels and localisation in human asthmatic bronchi
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1110
OP 1116
DO 10.1183/09031936.02.00205402
VO 20
IS 5
A1 C. Olgart Höglund
A1 F. de Blay
A1 J-P. Oster
A1 C. Duvernelle
A1 O. Kassel
A1 G. Pauli
A1 N. Frossard
YR 2002
UL http://erj.ersjournals.com/content/20/5/1110.abstract
AB Nerve growth factor (NGF) has recently been suggested to be an important mediator of inflammation. In support of this, serum levels of NGF have been shown to be enhanced in asthmatics. However, it has not yet been shown whether the levels of NGF are also altered locally in asthmatic airways, when compared with healthy subjects, and the localisation of potential sources of NGF in the human bronchus have not yet been described. The aim of the present study was to assess NGF levels in bronchoalveolar lavage fluid (BALF) from asthmatics and to compare them to those of control subjects. Furthermore, the authors wanted to localise potential sources of NGF in bronchial tissue, and to number NGF-immunopositive infiltrating cells in the bronchial submucosa. BALF and bronchial biopsies were obtained from seven control subjects and seven asthmatic patients by fibreoptic bronchoscopy. NGF protein levels were quantified by enzyme-linked immunosorbent assay in BALF. NGF localisation was examined by immunohistochemistry on bronchial biopsy sections. The asthmatics exhibited significantly enhanced NGF levels in BALF. Intense NGF-immunoreactivity was observed in bronchial epithelium, smooth muscle cells and infiltrating inflammatory cells in the submucosa, and to a lesser extent in the connective tissue. The asthmatics exhibited a higher number of NGF-immunoreactive infiltrating cells in the bronchial submucosa than control subjects. This study provides evidence that nerve growth factor is locally produced in the airways, and shows that this production is enhanced in asthmatics. These findings suggest that nerve growth factor is produced by both structural cells and infiltrating inflammatory cells in human bronchus in vivo, and the authors suggest that the increase in nerve growth factor protein in bronchoalveolar lavage fluid observed in asthmatic patients may originate both from structural cells, producing increased nerve growth factor levels in inflammatory conditons, and from the increase in nerve growth factor-immunopositive cells determined in the bronchial submucosa. This study was founded by INSERM. C. Olgart Höglund was supported by the Swedish Research Council (Sweden), Torsten and Ragnar Söderberg's Foundation, Erik and Edith Fernström's Foundation, Comité Départemental du Bas-Rhin Contre les Maladies Respiratoires et la Tuberculose, UCB Institute of Allergy (Brussels, Belgium).