Methods. Study Design Prospective, randomised, multicentre study. Centers
- Dott. E. Guffanti, IRCCS INRCA Casatenovo, Varese Italy
- Prof. F. Blasi, Università degli Studi di Milano, IRCCS Ospedale Maggiore Milan Italy
- Dott, M. Confalonieri, Ospedale Trieste, Italy Patients
We plan to enrol 30 patients :
Exhaled breath condensate (EBC) The breath condensate samples is collected using a specially designed condensing chamber (Ecoscreen; Jaeger, Hoechberg, Germany). The exhaled air entered and left the chamber though one-way inlet and outlet valves, thus keeping the chamber closed. The subjects wear noseclips and breathed tidally through a mouthpiece connected to the condenser for ten minutes. Approximately 1 ml of the sampled material is transferred to 2-ml plastic tube and stored at -70°C.
Interleukin-6 assay Interleukin-6 concentrations in the breath condensate will be measured using a specific enzyme immunoassay kit (EIA) (Cayman Chemical, Ann Arbor, USA). The assay is directly validated by means of gas chromatography/mass spectrometry in order to obtain a high correlation (r=0.95) between known amounts of IL-6 and the concentration measured by the EIA. The detection limit of the assay was 1.5 pg/ml after a two-hour development period.
TNF alfa TNF-alfa? serum levels will be measured by enzyme immunoassay (Cayman Chemical, Ann Arbor, USA)
Microbiology Quantitative culture of tracheal aspirate will be performed at steady state, every 3 months and at exacerbation. Molecular biology techniques for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, Chlamydia pneumoniae and Mycoplasma pneumoniae identification will be also applied on the same specimens.
Timetable Enrolment: between January 2004 and December 2005 Visits : Every 3 months and on each exacerbation/hospitalization a visit will be performed. Every month a phone call will be performed.
Follow-up: 12 months. End of the study : July 2006
- Visit 1. A complete history will be recorded. Inclusion and exclusion criteria will be checked. Informed consent will be collected and QoL questionnaire completed. Tracheal aspirate will be performed and divided into two aliquots : one for the local microbiology lab for quantitative cultures, and one for central lab for bacterial detection by PCR (stored at -80°C). Exhaled breath samples will be obtained.
- Follow-up visits. Every 3 months the patients will be recalled at the center and all Visit 1 procedures will be repeated. Number of exacerbations/hospitalisation will be recorded and QoL questionnaire completed.
- Exacerbation/hospitalisation visit. In presence of symptoms deterioration patients will be instructed to contact the center for a visit. All Visit 1 procedures will be repeated.
- End of the study visit. At the end of the 12 month follow-up all Visit 1 procedures will be repeated. Number of exacerbations/hospitalisation will be recorded and QoL questionnaire completed.
Treatment Patients will be randomised to receive usual care or usual care + Azithromycin 500 mg o.d. three day-a-week (Monday, Tuesday, Wednesday) for 6 months.
- reduction of inflammatory cytokines in EBC
- reduction of colony counts/eradication of bacteria on bronchial aspirates
- reduction of number of exacerbations/hospitalisations
- reduction of steroids and antibiotics use
- Quality of life