An Update on C-reactive Protein for Intensivists

Abstract

This review aims to summarise the physiology of C-reactive protein (CRP), its possible roles and limitations as an inflammatory and infective marker in intensive care medicine, and also the emerging roles of CRP in the pathogenesis of cardiovascular and autoimmune diseases. Observational and animal studies on uses of CRP were retrieved from the PubMed database without any language restrictions. Quantitative data were not pooled because of the heterogeneity of patient characteristics and disparate ways in which CRP was studied. Serum CRP concentrations are determined by the synthetic rate of its production in the liver regulated predominantly by interleukin-6. It has a half-life of 19 hours and is relatively slow in its onset and offset in response to an acute inflammatory process when compared to procalcitonin. It has some favourable properties and limitations as an inflammatory marker. An elevated CRP concentration is not specific to infections and the absolute CRP concentrations cannot be used to differentiate between bacterial, fungal and severe viral infections. The dynamic response of CRP to therapy that aims to modify the underlying inflammatory process and the clinical context of a patient are of pivotal importance when CRP concentrations are interpreted. CRP is found to be a significant partaker and prognostic factor in a wide range of cardiovascular and chronic diseases. In summary, CRP concentration is an important prognostic factor of many acute and chronic diseases. Serial CRP measurements may be useful to reflect a patient's response to therapy that aims to modify the underlying inflammatory process.

Impact of inflammation and concomitant glucocorticoid administration on plasma concentration of triazole antifungals in immunocompromised patients

“…First, CRP in patients with a triazole may not completely reflect the degree of inflammation. CRP has a half-life of 19 h and is relatively slow in its onset and offset [30]. Although the time lag between the profile of serum CRP and inflammatory state may have affected our results, this study was able to detect the influence of CRP on plasma exposure parameters of VRCZ in immunocompromised patients.…”

Comparison of the Effects of Lobectomy on Immunologic Function Between Video-Assisted Thoracoscopic Surgery and Traditional Open Surgery for Non–Small-Cell Lung Cancer

“…14 CRP was identified in 1930, and subsequently recognized as "acute-phase protein," an early indicator of inflammatory or infectious conditions; and then CRP has been used as a biomarker of disease activity, a test for tissue inflammation, a monitor of reflector therapy as well as a predictive tool of many acute and chronic diseases. 15,16 SAA, one of the chief positive acute-phase proteins, has been reported involving the regulation of numerous immunological responses when the inflammatory response to trauma, infection, or stress; it is often found to increase significantly within the first 48 hours after the event as well as has a quick decline for their short half-life. 17,18 Various diseases have been correlated with elevated IL-6 levels, including cancer, cardiovascular disease, and diabetes; IL-6 levels have been regarded as a vital inflammatory biomarker for the risk and severity of progression of the above diseases.…”

Infection and systemic inflammation, not ammonia, are associated with Grade 3/4 hepatic encephalopathy, but not mortality in cirrhosis

“…CRP concentrations are determined by the synthetic rate of its production in the liver, which is regulated predominantly by interleukin-6 [42]. Therefore, low CRP concentrations are likely to be explained by the fact that all these patients had significantly impaired or disrupted liver synthetic function [median MELD score 29 (IQR [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]].…”