title: Low-dose clarithromycin therapy modulates Th17 response in non-cystic fibrosis bronchiectasis patients.
abstract: BACKGROUND
  Th17 cells play a crucial role in neutrophilic inflammation and tissue injury in non-cystic fibrosis (non-CF) bronchiectasis. Clarithromycin demonstrates anti-inflammatory and immunomodulatory properties but the effect of long-term clarithromycin prophylaxis on the Th17 response in non-CF bronchiectasis is still unexplored.
  
  
  METHODS
  Th17 response was studied in 22 patients with stable non-CF bronchiectasis receiving daily 500-mg clarithromycin for 12 weeks. We analysed IL-17 concentrations in exhaled breath condensate (EBC) and peripheral blood Th17 cells, whereas functional parameters and clinical data were recorded in parallel.
  
  
  RESULTS
  Both, post-treatment absolute counts of CD4+IL17+ cells in peripheral blood and IL-17 levels in EBC decreased significantly (post-treatment CD4+IL17+ mean 2.418 ± 0.414 cells/μl versus pre-treatment 3.202 ± 0.507 cells/μl, p = 0.036 and post-treatment IL-17 mean levels 7.16 ± 0.47 pg/ml versus pre-treatment 9.32 ± 0.47 pg/ml, p < 0.001, respectively). Post-treatment EBC IL-17 levels decreased significantly in both patients who exhibited exacerbations and those who remained stable during the study period (mean 6.72 ± 0.37 versus 9.12 ± 0.64 pg/ml, p = 0.01 and 7.69 ± 0.9 versus 9.53 ± 0.72 pg/ml, p = 0.042, respectively), while pre-treatment and post-treatment levels did not differ between the two groups (p = 0.665 and p = 0.465, respectively). PaO(2) improved significantly (post-treatment mean 77.73 ± 2.23 mmHg versus pre-treatment 73.18 ± 2.22 mmHg, p = 0.025), while PaCO(2), post-bronchodilation FEV1, and post-bronchodilation FVC remained unaltered.
  
  
  CONCLUSIONS
  Our results argue for a reduction of both systemic and local Th17 response after prophylactic, low-dose clarithromycin administration in patients with non-CF bronchiectasis, suggestive of a potential anti-inflammatory and/or immunomodulatory action.
authors.affiliation: Department of Pneumonology, General Hospital G.Papanikolaou, Aristotle University of Thessaloniki, Exohi, 57010, Thessaloniki, Greece, evafouka@gmail.com.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Fouka
authors.forename: Eleftheria
authors.initials: E
authors.lastname: Lamprianidou
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Arvanitidis
authors.forename: Eirini
authors.initials: E
authors.lastname: Filidou
authors.forename: George
authors.initials: G
authors.lastname: Kolios
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Miltiades
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Paraskakis
authors.forename: Antonios
authors.initials: A
authors.lastname: Antoniadis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kotsianidis
authors.forename: Demosthenes
authors.initials: D
authors.lastname: Bouros
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D001944:Breath Tests; D001987:Bronchiectasis / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D017291:Clarithromycin / Q000008:administration & dosage*; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020381:Interleukin-17 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012494:Sampling Studies; D012720:Severity of Illness Index; D058504:Th17 Cells / Q000187:drug effects* / Q000276:immunology; D016896:Treatment Outcome
chemical_list: D020381:Interleukin-17; D017291:Clarithromycin