CRP and infection: Infection of the lung with either evidence of increased infection parameters (C-reactive protein > 2 mg/dl and/or leukocytes > 10,0000 cells/ml) that are not caused by a different pathologic process or evidence of pulmonary infiltration in the chest X-ray, requiring antibiotic therapy. Decrease of lung function testing results (forced expiratory volume in 1 s and vital capacity) by 20% or more in comparison with the baseline lung function testing.