Usefulness of Serum C-reactive Protein in the Management of Adult Community-acquired Pneumonia

抄録

C-Reactive protein (CRP) is widely used as a marker of infection, but there is insufficient evidence as to its usefulness in patients with community-acquired pneumonia (CAP). In the present study, we investigated the clinical usefulness of CRP in a retrospective study of 242 patients aged ≥ 14 years who were hospitalized with CAP. Patients were classified into three groups according to the number of days between disease onset and the initial measurement of CRP as follows: Group 1, 0-1 day; Group 2, 2-4 days; Group 3, ≥ 5 days. Patients in Groups 2 and 3, who had more severe pneumonia, had higher CRP levels. Over time, CRP levels decreased in the responders in Groups 2 and 3; specifically, in Group 2, median CRP levels on Days 0, 3, and 7 were 9.85, 5.33, and 0.81mg/dL, respectively, compared with 9.99, 4.29, and 0.70mg/dL, respectively, in Group 3. In patients not responding to initial treatment, median CRP levels increased from Day 0 to Day 3 (4.32 vs. 11.70mg/dL, respectively). In all non-responders, CRP levels on Day 3 were>50% of levels on Day 0. In conclusion, when measured approximately 48 h after disease onset, CRP is useful for evaluating the severity of pneumonia and predicting the response to treatment. A good clinical outcome is likely when CRP levels on Day 3 are ≤ 50% of those on admission.