P053 Use of extended-quantitative culture does not predict an imminent pulmonary exacerbation

Objectives: To determine if extended-quantitative culture, clinical or inflammatory markers could be used to predict an imminent PEx. Methods: Consecutive sputa (n = ≥2) were collected from 56 CF patients. Extended-quantitative bacterial culture was performed under aerobic, microaerophilic and anaerobic atmospheric conditions and total viable counts [TVCs] and ecological indexes were calculated. Patient metadata was recorded. Patients were stratified into groups: (1) those who remained clinically stable for >4 months (n = 37) and (2) thosewho experienced a PEx (n = 19) within 4 months of baseline. Logistic regression was performed to identify factors associated with a PEx. Results: Neither TVCs nor ecological indexes (e.g. community diversity) were independent predictors of an imminent PEx. However, in a univariable logistic regression, higher lung function (OR, 0.95; 95%CI, 0.91-0.98; P = 0.002) and BMI (OR, 0.80; 95%CI, 0.66-0.98; P = 0.03) at baseline were significantly associated with a reduced risk of a PEx. Higher CRP (OR, 6.3; 95%CI, 1.38-28.91; P = 0.02) and chronic azithromycin (OR, 3.96; 95%CI, 1.10-14.2; P = 0.04) at baseline were significantly associated with an elevated risk. Being female was associated with an elevated risk (OR, 3.0; 95%CI, 0.94-9.54; P = 0.06) and a higher CFQ-R respiratory symptom score at baseline was associated with a lower risk (OR, 0.96; 95% CI, 0.93-1.01; P = 0.09). The results of the multivariable logistic regression are shown in the Table. Conclusion: Baseline clinical parameters were better PEx predictors than sputum cultures, even when detailed microbiota were cultured and quantified. (Table Presented).