C-Reactive Protein: Re-evaluation of a Diagnostic Laboratory Test

C-reactive protein has been a measure of acute phase reactions to inflammation for 40 years. Recently improved quantitative assays in serum and cerebrospinal fluid (CSF) have allowed a re-evaluation of its potential as a diagnostic laboratory test. The main advances in the newer methods have been that they can provide rapid (hours) information on the hepatocyte synthesis of this molecule during immune response. We have tested its value in patients with presumed bacterial meningitis. Based on our experience, newer standardized, quantitative assessments of C-reactive protein can be very useful in distinguishing between bacterial and other forms of meningeal irritation during the first few days of hospitalization. Other investigators have indicated that by serial measurements important information on the resolution or continuation of inflammatory processes can be obtained. We recommend improved standardization of this test, and recalculation of its usefulness as a diagnostic laboratory test.