C-reactive protein fifty years on

Area of Science:

• Biochemistry
• Immunology
• Molecular Biology

Background:

• C-reactive protein (CRP) discovery led to understanding the acute-phase reaction, a fundamental response to injury.
• CRP and serum amyloid P component (SAP) form a unique, evolutionarily conserved plasma protein family.
• These proteins bind to damaged cells and microorganisms, playing roles in innate immunity and inflammation.

Purpose of the Study:

• To review the structure, function, and clinical significance of CRP and SAP.
• To highlight the role of CRP in the acute-phase response and its clinical applications.
• To describe the structural similarities and functional differences between CRP and SAP.

Main Methods:

• Review of existing literature on CRP and SAP.
• Analysis of the binding properties and complement activation by CRP.
• Examination of the distribution and function of SAP in normal tissues and amyloid deposits.

Main Results:

• CRP specifically binds to a diverse range of substances from damaged cells and microbes.
• Complexed CRP activates the complement system, acting as a protective mechanism against injury.
• Serum CRP measurement is a valuable clinical tool for diagnosing organic disease and monitoring inflammatory conditions.
• SAP shares structural similarity with CRP but is not an acute-phase reactant in humans.
• Amyloid P component (AP), identical to SAP, is consistently found in amyloid deposits and normal vascular tissues.

Conclusions:

• CRP is a crucial component of the acute-phase reaction, with significant diagnostic and prognostic value.
• While primarily protective, CRP can also contribute to inflammatory processes.
• SAP, despite structural resemblance to CRP, has distinct biological roles, particularly in amyloidosis and tissue structure.