Correlation between Serum C-Reactive Protein Levels and CURB-65 in Elderly Patients With Community-Acquired Pneumonia

Background: CURB-65 is an important clinical score for severity of community-acquired pneumonia (CAP). C-reactive protein (CRP) is an acute phase protein marker for bacterial infection or tissue inflammation. Serum CRP levels are well correlated with the severity of CAP. Objective: To investigate whether serum levels of CRP correlates with CURB-65 ranking in hospitalized patients with CAP. Methods: We studied 858 patients aged 18-90 years who were hospitalized with CAP during a period of two years in the departments of Internal Medicine at Ziv Medical Center in Safed, Israel. Five hundred patients who met the inclusion and exclusion criteria were included. CURB-65 and serum levels of CRP within 24 hours of admission were collected for each participant. The correlation between serum CRP levels and CURB-65 was analyzed by Spearman's rank correlation test presented by correlation coefficient (R). Results: The mean CRP levels and CURB-65 score were 114 ± 100 mg/dL, 1.4 ± 1.1 points, respectively. No significant correlation was found between CRP and CURB-65 for all study group (r = -0.014, p = 0.768). Nevertheless, we found a significant correlation between CRP levels and CURB-65 in 320 patients aged ≥ 65 years (r = 0.126, p = 0.024). Conclusions: In this study we found a significant correlation between CRP levels and CURB-65 among elderly patients aged ≥ 65 years but not among patients below the age 65 years. CRP measurements could be used as adjuvant biomarker to CURB-65 for disease severity assessment in elderly patients with CAP.