[Diagnostic value of C-reactive protein in comparison with erythrocyte sedimentation as routine admission diagnostic...

In a prospective study the diagnostic relevance of C-reactive protein (CRP) as a screening parameter for inflammatory diseases was compared to the erythrocyte sedimentation rate (ESR). At time of hospitalization CRP, ESR and other routine laboratory tests were performed. After taking history and clinical examination, the responsible physician had to answer a first questionnaire and a second at the time of patient discharge. At the time of admission, elevation of CRP was expected by the treating physician in 40.3% of patients, and elevation of ESR in 43.2%. An unexpected elevation of CRP or ESR was found in 38/303 cases (12.5%). In 22/38 patients only CRP was elevated, but ESR only was elevated in 13/38 cases. In summary, measurement of CRP and/or ESR was felt by the treating physician to have been helpful in 25.1% of all patients. Due to the fast rise of CRP, all patients with bacterial pneumonia showed increased CRP at the time of hospitalization (23/23), but the ESR was still in normal range in some of these patients (normal ESR in 5/23). Also in patients with COPD or asthma and clinical evidence for infection, or patients with bacterial gastroenteritis, CRP turned out to be the more sensitive parameter. In conclusion, CRP is a valuable screening test in acutely ill patients, has a higher sensitivity and (as shown by other authors) higher specificity than ESR. In addition, the short half-life of CRP makes it a useful parameter for the follow-up of patients with e.g. infections under antibiotic treatment.