Diagnostic and Prognostic Significance of Serum C-Reactive Protein Levels in Patients Admitted to the Department of Medicine

Background: Despite its apparent role as a marker of different disease processes, to date, no study has presented comprehensive comparative data regarding the distribution of serum C-reactive protein (CRP) levels in all admitted patients. We aimed to examine the distribution of serum CRP levels in internal medicine patients and to find whether initial serum CRP value had a diagnostic and prognostic significance. Methods: Serum CRP levels together with epidemiologic, clinical, and laboratory data were analyzed for 370 consecutive adult patients admitted to the department of internal medicine during a 2-month period. Results: The median CRP level on admission was 24 mg/L, with a range between 0 and 346 mg/L. Infections had significantly higher median CRP than noninfections (99 versus I I mg/L), and bacterial infections had distinctively higher CRP (120 mg/L) compared with nonbacterial infections (32 mg/L). The highest noninfectious median CRP was recorded in inflammatory bowel disease exacerbation (107 mg/L). Moreover, serum CRP was divided into 5 ranges. Very high CRP >200 mg/L was a marker of sepsis. In contrast, low CRP range (<10 mg/L) was characteristic to cardiovascular diseases and viral infections, but included none of the patients with severe infections or sepsis. Furthermore, higher CRP was significantly associated with mortality, the need for intubation, and longer hospitalization, and had better distinguishing ability compared with erythrocyte sedimentation rate or platelets count for the comparison of major disease categories, such as bacterial infections, inflammatory and rheumatic disease, viral infections, and cardiovascular disorders. Conclusions: Initial serum CRP has an important role as a diagnostic and prognostic tool in patients admitted to internal medicine.