subject of attention objectives: Neutrophilic inflammation is a major feature of COPD Several factors in bronchial secretions have been identified as chemoattractants for neutrophils.

subject of attention objectives: Neutrophilic inflammation is a major feature of COPD Several factors in bronchial secretions have been identified as chemoattractants for neutrophils. The not past nor future study was designed to assess the contribution of interleukin (IL)-8 and leukotriene [Bsub4] (LT[Bsub4]) to neutrophil chemotaxis evok by dint of sputum obtained from patients with established COPD

Design: Sputum supernatant of 20 patients with COPD was used as chemoattractant in a 96-well chemotaxis chamber, with later quantification of migrated cells from a luminescence assay. The contribution of IL-8 and LT[Bsub4] to chemotaxis was determined by the agency of addition of a neutralizing antibody and a selective receptor antagonist, respectively.

Measurements and results: COPD sputum caused neutrophil chemotaxis in a concentration-dependent manner, with a maximum reply evoked with a 10-fold dilution of the original sample. Pretreatment of sputum or neutrophils with either an anti-IL-8 antibody or the LT[Bsub4] antagonist, SB 201146 l to a concentration-dependent inhibition of sputum-induced neutrophil chemotaxis, with a maximum suppression (mean [+ or -] SEM) of 292 [+ or -] 49% (p < 0001) from baseline through 100 ng/mL of anti-IL-8 antibody, and 456 [+ or -] 7% (p < 002) by means of 10 [micro]mol/L of SB 201146 The combination of the anti-IL-8 antibody and SB 201146 inhibited neutrophil chemotaxis, further this was not significantly greater than the issue of SB 201146 or anti-IL-8 alone.

Conclusions: These data confirm the importance of IL-8 and LT[Bsub4] as chemoattractants for neutrophils in bronchial secretions from patients with COPD and glance at that specific inhibitors may have therapeutic potential in COPD

tonic words: chemotaxis; COPD; human neutrophils; induced sputum; interleukin 8; leukotriene [Bsub4]

Abbreviations: BSA = bovine serum antigen; E[Csub50] = effective concentration causing a 50% fall; HBS = Hanks' balanced salt solution; HEPES = hydroxylethyl piperazine-ethanesulfonic acid; IL = interleukin; LT[Bsub4] = leukotriene [Bsub4]; PB = phosphate-buffered saline solution

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COPD is a debilitating inflammatory disease of the lung characterized by the agency of an increased presence of neutrophils and macrophages in the airways of affected patients. (12) Neutrophils cause proteinases such as neutrophil elastase, matrix metalloproteinases, and cathepsins that may lead to emphysema and mucous hypersecretion. (34) Recruitment of neutrophils to the airways requires their adhesion to pulmonary and bronchial epithelial small cavitys and subsequent migration into the airways and alveoli. (56) Previous studies have indicated that airway secretions from patients with cystic fibrosis, bronchiectasis, (7) or COPD contain chemoattractants for neutrophils. (8) However, the contribution of different neutrophil chemoattractants may vary between different diseases, or smooth in different stages of the same disease.

Understanding the mechanisms leading to airway neutrophilia in COPD is important, since several chemoattractants may forward as targets for future anti-inflammatory mix with drugss These anti-inflammatory agents may potentially bring the rate of decline of lung function in these patients on ameliorating neutrophil-mediated tissue destruction. Several neutrophil chemotactic factors have been implicated, including interleukin (IL)-8, tumor necrosis factor-[alpha], (8) and leukotriene [Bsub4] (LT[Bsub4]) with a predominant part for IL-8 in cystic fibrosis, (9) LT[Bsub4] in bacterial exacerbations of COPD (10) and a combination of the one and the other IL-8 and LT[B.sub.4] in bronchiectasis. (7) Moreover, unlike IL-8, (11) LT[Bsub4] has also been shown to postpone neutrophil survival by inhibiting apoptosis. (12) To further investigate the contribution of IL-8 and LT[Bsub4] to neutrophil chemotaxis in stable COPD we used sputum supernatant from steroid-naive COPD patients as a chemoattractant. The parts of LT[B.sub.4] and IL-8 were determined using a selective LT[Bsub4] receptor antagonist, SB 201146 (13) and a monoclonal anti-IL-8 antibody, respectively.

There is still ongoing debate about the benefit of inhaled or oral corticosteroids in patients with stable COPD (14) While corticosteroids have no result on neutrophilic inflammation, (15,16) they may influence cytokine plains (17,18) or neutrophil survival and activation. (19-21) Hence, solitary steroid-naive patients were chosen to omit a possible influence of concomitant anti-inflammatory treatment in succession sputum chemotaxis.

MATERIALS AND METHODS

Patients

Twenty patients with diagnosed COPD underwent sputum induction. All patients fulfilled the diagnostic criteria of the British Thoracic Society. (22) None of the patients had actively smok for at least 6 month prior to the study; received inhaled or oral corticosteroids, or other systemic mix with drugss including theophylline, antibiotics or nonsteroidal anti-inflammatory drugs; or reported any acute exacerbations for at least 4 weeks prior to sputum induction. The contemplation was approved by local regulatory authorities, and each patient gave informed written consent

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