title: C-Reactive Protein in Stable Cystic Fibrosis: An Additional Indicator of Clinical Disease Activity and Risk of Future Pulmonary Exacerbations.
abstract: BACKGROUND
  In stable adult cystic fibrosis (CF) patients, we assessed the role of baseline high sensitivity C-reactive protein (hs-CRP) on CF clinical variables and frequency of intravenous (IV) treated pulmonary exacerbations (PExs) 1-year post-baseline.
  
  
  METHODS
  We recruited 51 clinically stable CF patients from our Adult CF Center. We incorporated collected parameters into Matouk CF clinical score and CF questionnaire-revised quality of life score (QOL). We used the clinical minus complications subscores as a clinical disease activity score (CDAS). We dichotomized our patients according to the cohort median baseline hs-CRP of 5.2 mg/L.
  
  
  RESULTS
  Patients in the high hs-CRP group (≥ 5.2 mg/L) demonstrated worse CDAS (r=0.67, p=0.0001) and QOL scores (r=0.57, p=0.0017) at a given FEV1% predicted. In both hs-CRP groups, prior-year IV-treated PExs and baseline CDASs were significant predictors of future IV-treated PExs. Interestingly, the association between baseline CDAS and future PExs frequency was more robust in the high compared to the low hs-CRP group (r=-0.88, p<0.0001, r=-0.48, p=0.017, respectively) with a steeper regression slope (p=0.001). In addition, a significant interaction was demonstrated between elevated baseline hs-CRP levels and CDASs for the prediction of increased risk of future PExs (p=0.02). This interaction provided an additional indicator of clinical disease activity and added another dimension to the prior year PExs frequency phenotype to identify patients at increased risk for future PExs.
  
  
  CONCLUSIONS
  Stable CF patients with elevated baseline hs-CRP (≥ 5.2 mg/L) demonstrated worse clinical disease activity and QOL scores at a given level of disease severity (FEV1% predicted). Elevated baseline hs-CRP values combined with clinical disease activity scores are associated with increased risk for future IV-treated PExs even in those with mild clinical disease activity scores.
authors.affiliation: Adult Cystic Fibrosis Clinic, Montreal Chest Institute, McGill University, Canada; McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada.
authors.forename: Elias
authors.initials: E
authors.lastname: Matouk
authors.affiliation: McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada; Meakins-Christie Laboratories, Montreal Chest Institute, McGill University Health Centre, Canada.
authors.forename: Dao
authors.initials: D
authors.lastname: Nguyen
authors.affiliation: McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada; Department of Epidemiology, Biostatistics and Occupational Health, Montreal Chest Institute, McGill University Health Center, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Benedetti
authors.affiliation: Adult Cystic Fibrosis Clinic, Montreal Chest Institute, McGill University, Canada.
authors.forename: Joanie
authors.initials: J
authors.lastname: Bernier
authors.affiliation: Adult Cystic Fibrosis Clinic, Montreal Chest Institute, McGill University, Canada; Department of Medicine, McGill University, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Gruber
authors.affiliation: Adult Cystic Fibrosis Clinic, Montreal Chest Institute, McGill University, Canada; McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Landry
authors.affiliation: Department of Medicine, McGill University, Canada; Meakins-Christie Laboratories, Montreal Chest Institute, McGill University Health Centre, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Rousseau
authors.affiliation: McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada.
authors.forename: Heather G
authors.initials: HG
authors.lastname: Ahlgren
authors.affiliation: McGill University Health Center Research Institute, Canada; Meakins-Christie Laboratories, Montreal Chest Institute, McGill University Health Centre, Canada; Division of Pediatric Respiratory Medicine, Montreal Children's Hospital, Canada.
authors.forename: Larry C
authors.initials: LC
authors.lastname: Lands
authors.affiliation: Department of Human Genetics, Respiratory Division, McGill University, Canada; McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Wojewodka
authors.affiliation: Department of Human Genetics, Respiratory Division, McGill University, Canada; McGill University Health Center Research Institute, Canada; Department of Medicine, McGill University, Canada.
authors.forename: Danuta
authors.initials: D
authors.lastname: Radzioch
keywords: Chronic pulmonary infections; Clinical disease severity; Clinical scoring; Inflammation; Lung function; Quality of life; Systemic biomarkers