Canine C-reactive protein (cCRP) is a major acute phase protein in dogs. Its concentration increases rapidly and significantly during systemic inflammation and subsequently decreases quickly following the elimination of the source of inflammation.

Several studies support the view that cCRP is a valuable diagnostic marker for the detection of the acute phase response in dogs. Its concentration has been shown to increase rapidly in various disorders including viral and bacterial infections, sepsis and pyometra, as well as in surgical trauma. Measuring cCRP from serum can be used in routine canine medicine (1-3 and references therein).

CRP belongs to a family of pentraxins. These evolutionally conserved proteins are pentamers and have calcium-dependent ligand binding properties. CRP is composed of five identical subunits that form a ring-like structure.

References:
1. Kjellgaard-Hansen, M. Canine C-reactive protein – a study on the applicability of canine serum C-reactive protein. Ph.D. Thesis. 2004, The Royal Veterinary and Agricultural University, Denmark.

2. Cerón J.J., Eckersall P.D. and Martýnez-Subiela S. Acute phase proteins in dogs and cats: current knowledge and future perspectives. Vet. Clin. Pathol. 2005 Jun; 34(2):85-99.

3. Eckersall P.D. and Bell R. Acute phase proteins: Biomarkers of infection and inflammation in veterinary medicine. Vet. J. 2010, 185:23-27.

Related information:
Veterinary diagnostics

CRP Products

CRP Monoclonal Antibody Product

Cat.# Product name
4CC5 Monoclonal mouse anti-canine C-reactive protein (cCRP) antibodies

CRP Antigen Product

Cat.#   Product name
8CC5 Recombinant canine C-reactive protein (cCRP)  

TechNotes

Canine CRP (cCRP) TechNotes

Antibody pair recommendations

The most sensitive capture-detection pairs are given in the table on the right. These recommendations are based on the results obtained using our in-house DELFIA® immunoassay platform. Please note that the antibodies can perform differently depending on the assay platform and reaction conditions. Therefore, the best antibody combinations should always be validated separately for each assay.

A sandwich immunoassay for cCRP detection

Three of our four MAbs can be used in sandwich immunoassays. The recommended MAb combinations show high sensitivity (up to 0.1 ng/ml) and a long linearity range in a sandwich fluoroimmunoassay. Figure 1. shows a calibration curve for native cCRP using MAbs cCRP11 and cCRP1 for capture and detection respectively.

Figure 1. Calibration curve of native cCRP in a sandwich
fluoroimmunoassay. cCRP11 was used as a capture antibody and Eu3+-
labeled cCRP1 as a detection antibody in this assay.

Detection of cCRP in serum samples

We tested the MAbs for their ability to detect endogenous cCRP in serum samples by measuring cCRP concentrations from serum samples from dogs with systemic inflammation of different origins and serum samples from healthy dogs. Most MAb combinations were able to detect endogenous cCRP in a reliable manner. Figure 2 shows an example of measuring cCRP concentrations using cCRP34 and cCRP1 as capture and detection antibodies respectively. Serum samples from 34 dogs with an inflammation and from 8 healthy dogs were measured. The results demonstrate that the concentration of cCRP in the group of animals with inflammation is considerably higher compared to healthy dogs.


Figure 2. cCRP levels in serum of healthy dogs or dogs with systemic
inflammation. cCRP34 and Eu3+-labeled cCRP 1 were used as capture
and detection MAbs respectively.

Recombinant cCRP is partially glycosylated

Our recombinant cCRP is produced in a eukaryotic expression system that allows for the glycosylation of the protein. When the purified protein was run in SDS-PAGE under reducing conditions it migrated as two separate bands, similarly to the native cCRP (see Figure 3). The faster migrating bands (b) represent the non-glycosylated subunits. The bands migrating more slowly (a) represent the glycosylated subunits. The differences in their migration indicates that the glycosylation patterns are not identical. However, this does not affect the immunochemical properties of the recombinant cCRP.


Figure 3. Comparison of recombinant and native cCRP in SDS-PAGE. 3 μg
of purified proteins were run in 12.5% gel under reducing conditions. The
gel was stained with Coomassie brilliant blue R-250.
a: glycosylated CRP
b: non-glycosylated CRP