CRP is an acute-phase protein in inflammatory processes. Which among the following is the expansion of ‘C’ in CRP?
**Core Concept**
C-Reactive Protein (CRP) is an acute-phase protein synthesized in the liver in response to inflammation, infection, or tissue damage. It is a marker of systemic inflammation and plays a crucial role in the acute phase response.
**Why the Correct Answer is Right**
The 'C' in CRP stands for C or Capsular polysaccharide, as CRP was first discovered by Tillett and Francis in 1930 as a substance in the serum of patients with pneumococcal pneumonia that precipitated with the C polysaccharide of the pneumococcus. CRP binds to the C polysaccharide of the pneumococcus, marking it for phagocytosis by neutrophils and other immune cells. This is a key mechanism by which CRP contributes to the elimination of pathogens during an inflammatory response.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not provide any relation to the discovery of CRP or its function.
**Option B:** This option is incorrect as it is related to another acute-phase protein, Serum Amyloid A (SAA), which is also elevated in response to inflammation but is distinct from CRP.
**Option D:** This option is incorrect as it is related to another protein, Complement Component 1 (C1), which is part of the complement system but is not directly related to CRP.
**Clinical Pearl / High-Yield Fact**
CRP is a useful marker of inflammation and infection, but its levels can also be elevated in other conditions such as malignancy, autoimmune diseases, and tissue damage.
**Correct Answer:** C. Capsular