C-reactive protein

 C-reactive protein

C-reactive protein(CPR) is an acute phase reactant synthesized by the liver, which opsonizes invading pathogens. Circulating concentrations of CPR increase within 6 hours of the start of an inflammatory stimulus. Serum concentrations of CPR provide a direct biomarker of acute inflammation and, because the serum half-life of CPR is 18 hours, levels fall promptly once the inflammatory stimulus is removed. Sequential measurements are useful in monitoring disease activity. For reasons that useful in monitoring disease are associated with only minor elevations of CPR despite unequivocal evidence of active inflammation. These include systemic lupus erythematosus(SLE), systemic sclerosis, ulcerative colitis and leukemia. An important practical point is that if the CRP is raised in these conditions, it suggests intercurrent infection rather than disease activity. Since the CRP is a more sensitive early indicator of the acute phase response, it is generally used in preference to the erythrocyte sedimentation rate(ESR). If both ESR and CRP are used, any discrepancy should be resolved by assessing the individual determinants of the ESR, while are discussed below.