Preparation of canine C-reactive protein serum reference material: A feasibility study

Acute phase proteins in cattle and swine: A review

The major acute phase proteins (APPs) in cattle are haptoglobin (Hp) and serum amyloid A (SAA), and in swine, are Hp, SAA, C-reactive protein (CRP), and Pig major acute phase protein (Pig-MAP). Many methodologic assays are presently available to measure these parameters, which are still being improved to increase their specificity, sensitivity, user-friendliness, and economic availability. In cattle, the main applications are the diagnosis and monitoring of frequent diseases such as mastitis and metritis in dairy cows and respiratory problems in young calves. In pigs, APPs are useful in the control of bacterial and viral infections, and they may be used at the slaughterhouse to monitor subclinical pathologies and improve food safety. The utility of APP in animal production must not be forgotten; optimization of protocols to improve performance, welfare, and nutrition may benefit from the use of APPs. Other sample types besides serum or plasma have potential uses; APP determination in milk is a powerful tool in the control of mastitis, saliva is a non-invasive sample type, and meat juice is easily obtained at the slaughterhouse. Increasing our knowledge of reference intervals and the influence of variables such as age, breed, sex, and the season is important. Finally, worldwide harmonization and standardization of analytical procedures will help to expand the use of APPs.

Changes in canine C-reactive protein levels following orthopaedic surgery: a prospective study

C-reactive protein (CRP) is a powerful biomarker for inflammation, infection and sepsis. However, no reports have investigated canine CRP (c-CRP) concentration changes after orthopaedic procedures. If c-CRP changes were better characterized, it may be possible to identify postoperative complications more quickly. The purpose of this study was to clarify the characteristic changes in serum c-CRP after orthopaedic surgery in dogs. Blood samples were collected from 98 dogs on Day 0 (preoperatively), and then on Days 1, 4, 7, 10 and 13 postoperatively. Day 1 blood sampling was performed 12–24 h postoperatively. We classified the dogs into four groups based on changes in c-CRP pre- to postoperatively. Group 1 dogs showed a peak c-CRP concentration on Day 1, followed by decreases of ≥ 1 mg/dL. Group 2 dogs showed changes in c-CRP concentration by Day 4 that were within ± 1 mg/dL compared with Day 1. Dogs in Group 3 showed a peak c-CRP concentration on Day 4, followed by decreases of ≥ 1 mg/dL. Group 4 dogs showed an initial decrease in c-CRP, then an increase of ≥ 1 mg/dL. Group 1 was the largest group, with 63 dogs. c-CRP on Days 0, 1, 4, 7, 10 and 13 was 0.83 ± 1.03 mg/dL, 8.10 ± 3.15 mg/dL, 3.76 ± 1.94 mg/dL, 1.63 ± 0.92 mg/dL, 0.96 ± 0.70 mg/dL and 0.68 ± 0.51 mg/dL, respectively. Serum c-CRP concentration on Day 1 was significantly higher than at every other timepoint (P < 0.001). In Group 2, surgical site complications were confirmed in 9/15 dogs. In Group 3, surgical site complications were confirmed in 7/14 dogs. In Group 4, two surgical site problems and three surgical site infections were observed, and visceral disease was found in one dog. In Group 1, peak c-CRP was seen on Day 1 postoperatively in 63 dogs (64%), with c-CRP level decreasing by half at each subsequent measurement, which may describe a typical c-CRP change in orthopaedic patients. If deviation from this typical change is observed postoperatively, as in Groups 2–4, this may suggest possible complications.

A new automated turbidimetric immunoassay for the measurement of canine C-reactive protein

BACKGROUND

In dogs, as in humans, C-reactive protein (CRP) is a major acute phase protein that is rapidly and prominently increased after exposure to inflammatory stimuli. CRP measurements are used in the diagnosis and monitoring of infectious and inflammatory diseases.

OBJECTIVES

The study aim was to develop and validate a turbidimetric immunoassay for the quantification of canine CRP (cCRP), using canine-specific reagents and standards.

METHODS

A particle-enhanced turbidimetric immunoassay was developed. The assay was set up in a fully automated analyzer, and studies of imprecision, limits of linearity, limits of detection, prozone effects, and interferences were carried out. The new method was compared with 2 other commercially available automated immunoassays for cCRP: one turbidimetric immunoassay (Gentian CRP) and one point-of-care assay based on magnetic permeability (Life Assays CRP).

RESULTS

The within-run and between-day imprecision were <1.7% and 4.2%, respectively. The assay quantified CRP proportionally in an analytic range up to 150 mg/L, with a prozone effect appearing at cCRP concentrations >320 mg/L. No interference from hemoglobin (20 g/L), triglycerides (10 g/L), or bilirubin (150 mg/L) was detected. Good agreement was observed between the results obtained with the new method and the Gentian cCRP turbidimetric immunoassay.

CONCLUSIONS

The new turbidimetric immunoassay (Turbovet canine CRP, Acuvet Biotech) is a rapid, robust, precise, and accurate method for the quantification of cCRP. The method can be easily set up in automated analyzers, providing a suitable tool for routine clinical use.