Download CRP (C-Reactive Protein)

C- reactive protein (CRP)
• C- reactive protein (CRP) was so named because it was first
discovered as a substance in the serum of patients with acute
inflammation that reacted with the C- (capsular) polysaccharide of
pneumococcus
• CRP is phylogenetically a plasma protein, that participates in the
systemic response to inflammation.
• Its plasma concentration increases during inflammatory states
• CRP is a pattern recognition molecule, binding to specific
molecular configurations that are typically exposed during cell
death or found on the surfaces of pathogens.
• Its rapid increase in synthesis within hours after tissue injury or
infection suggests that it contributes to host defense and that it is
part of the innate immune response
CRP is used
mainly as a
marker of
inflammation
CRP (C-Reactive
Protein) – plasma
protein released by the
liver in response to
proinflammatory
cytokines: is an
indicator of
inflammation.
• CRP used to:
• Establish if inflammation is present
• Monitor course of disease in patients with a known disease process
• CRP is one of several proteins that are often referred to as acute phase
reactants and is used to monitor changes in inflammation associated with
many infectious and autoimmune diseases
Principle
• The latex reagent is a suspension of polystyrene latex particles of
uniform size coated with the IgG fraction of an anti-human CRP specific
serum.
• Latex particles allow visual observation of the antigen-antibody
reaction (CRP-IgG anti-CRP).
• If the reaction takes place, due to the presence of C-reactive protein in
the serum, the latex suspension changes its uniform appearance and a
clear agglutination becomes evident.
• This change occurs because the C-reactive protein present in the serum
reacts with the IgG coated to the latex particles.
• When the latex is mixed with the serum, if the serum contains
approximately more than 6 mg/l or 0.6 mg/dl of C-reactive protein, a
clear agglutination will appear. Results are expressed in mg/l of CRP.
Interpretation of the results
• The presence of agglutination indicates a content of C-reactive
protein in the serum equal to or greater than 6 mg/L(≥6 mg/L)
• The absence of agglutination indicates a content of C-reactive
protein in the serum of less than 6 mg/L (≤6 mg/L)
SEMIQUANTITATVE TEST
Typhoid
• An infectious feverish disease caused by the bacterium
Salmonella typhi and less commonly by Salmonella
paratyphi.
• The infection always comes from another human,
either an ill person or a healthy carrier of the
bacterium.
• Persons with typhoid fever carry the bacteria in their
bloodstream and intestinal tract
• Transmitted through the ingestion of food or drink
contaminated by the feces or urine of infected people
• The bacterium
refrigeration.
can
withstand
both
drying
and
H( flagella ) antigens
O (somatic) antigens
Vi (Virulence) capsular
polysaccharide antigens
O (somatic) antigens
• LPS in the cell wall;
• Heat stable
• Less immunogenic
• Agglutination with antisera:
Fine, compact, granular
chalky clumps
H (flagella) antigens
Present in flagella;
 Heat labile;
 Strongly immunogenic;
Induce rapid & High Ab titres;


Agglutination with antisera:
Large, loose, cotton wool
clumps
How does the bacteria cause disease ?
Ingestion of contaminated food or water
Salmonella typhi
Carried by white blood cells into the liver, spleen, and bone marrow
Multiply and reenter the bloodstream (Clinical illness)
Bacteria invade the gallbladder, biliary system, and the lymphatic tissue of the
bowel and multiply in high numbers
Then pass into the intestinal tract (can be identified for diagnosis in cultures
from the stool)
Typhoid ulcers can cause perforation and hemorrhage
Symptoms
Rose spots
Aches and pains
High fever
Diarrhea
Chest congestion
Typhoid Meningitis
• Antigens:
•
•
•
•
Suspension of S. typhi "O" antigen, O
Suspension of S. typhi "H" antigen; H
Suspension of S. paratyphi A "H" antigen, PA
Suspension of S. schottmuelleri "H" antigen, PB
• Antibody:
serum of suspected patient
1. The best known carrier was "Typhoid
Mary“; Mary Mallon was a cook in Oyster
Bay, New York in 1906 who is known to
have infected 53 people, 5 of whom died.
2. Later returned with false name but
detained and quarantined after another
typhoid outbreak.
3. She died of pneumonia after 26 years in
quarantine.