Biomarker Sample Submission Form
Why Use Biomarkers?
There has been much debate about what constitutes a biomarker which has led to confusion in some areas. However, this does not detract from their usefulness in many clinical situations.
A biomarker can be defined as a biological molecule found in blood, body fluids or tissues that is a sign of either normal or abnormal processes, or signs of a disease. Biomarkers may be used to see how a body responds to treatment for a disease or condition.
Some biomarkers can be very specific, but most are more generic. We believe that it is this lack of specificity that confers clinical value on biomarkers such as acute phase proteins (APPs). Circulating concentrations of APPs like C-reactive protein (CRP) increase dramatically, often by several hundred-fold, and rapidly in response to numerous clinical conditions. Furthermore, they also drop very rapidly when the stimulus (disease state) is resolved. Consequently, biomarkers such as CRP provide a good snapshot of either disease progression or resolution in near real-time. Testing for CRP can now be rapidly and conveniently performed in the clinic. These allow for timely and objective monitoring of treatment efficacy, indicating if it can be stopped or if treatment protocols require modification.
Many available tests are semiquantitative at best, and therefore do not allow monitoring of subtle changes during the course of treatment or periods of remission. Examples of such tests are lateral flow devices. These are helpful in making rapid diagnostic decisions, but they lack the precision needed for quantitative disease monitoring. On the other hand, the SPARCLTM CRP assay is extremely sensitive and measures over a wide range of biomarker concentrations, making it an ideal method for disease monitoring.
The lack of specificity of CRP allows for numerous diseases, once diagnosed, to be monitored using only a single test. The extreme sensitivity of the CRP test enables monitoring using only a small drop of blood which can be important for smaller breeds. The need for such as small sample has allowed some practices to take a baseline CRP measurement from residual blood samples routinely taken for diagnostic purposes. Ongoing longitudinal CRP measurements can then indicate treatment efficacy. Dependant on the animal’s diagnosis, urine or faecal samples can be collected by the owner and returned to the practice for monitoring purposes.
Examples.
CRP is produced by the liver and released into the blood in response to a wide range of localised or systemic inflammatory conditions. Therein lies its value as a routine disease monitoring biomarker. A single test allows the clinician to objectively observe progress from many different inflammation inducing conditions. If levels increase during or after treatment, this is a clear sign that treatment was not fully effective and alternative therapies or interventions are necessary. However, treatment induced return to a normal state will result in a dramatic drop in serum CRP levels. Examples are:
- Monitoring antibiotic responses in a wide range of bacterial infections
- Monitoring steroid responses to various inflammatory conditions such as steroid responsive meningitis, inflammatory bowel disease and immune mediated polyarthritis
- Resolution of corrective surgical procedures
Multiple Marker Testing.
At PDx, we aim to introduce a range of different biomarker tests all based on the rapid SPARCLTM luminescence platform. Some will be generic, such as CRP for monitoring purposes. Others will be more specific to act as a diagnostic tool. When the two are measured together during diagnostic workup, it should be possible to obtain rapid, in practice diagnostic decisions and monitor therapeutic progress from the outset of treatment.
Our Biomarkers
Biomarker | Indications | References |
---|---|---|
CRP | All | Biomarkers in canine inflammatory bowel disease diagnostics |
PCT | Antibiotic Stewardship | Investigation of a commercial ELISA for the detection of canine procalcitonin |
Haptoglobin Canine | Lymphoma | Development of a time-resolved fluorometry based immunoassay for the determination of canine haptoglobin in various body fluids |
SAA Feline | Pneumonia | A Clinical Investigation on Serum Amyloid A Concentration in Client-Owned Healthy and Diseased Cats in a Primary Care Animal Hospital |
COMING SOON
Biomarker | Indications | References | |
---|---|---|---|
Troponin | Heart Disease | Cardiac troponin-I concentration in dogs with cardiac disease | |
SAA Canine | Pneumonia | The Utility of Acute‐Phase Proteins in the Assessment of Treatment Response in Dogs With Bacterial Pneumonia | |
Haptoglobin Feline | Lymphoma | Serum haptoglobin concentrations in feline inflammatory bowel disease and small-cell alimentary lymphoma: a potential biomarker for feline chronic enteropathies | |
AGP Feline | FIP | Cardiovascular-renal axis disorder and acute-phase proteins in cats with congestive heart failure caused by primary cardiomyopathy | |
Canine Lactoferrin | Chronic Enteropathies | The use of faecal lactoferrin as a marker of intestinal inflammation in dogs with chronic enteropathy | |
Canine Cortisol | Cushings | Evaluation of Basal Serum or Plasma Cortisol Concentrations for the Diagnosis of Hypoadrenocorticism in Dogs | |
Canine PAP-1 | Pancreatitis | In development |

Additional References
CRP
PCT
This is a biomarker specific for bacterial infections. The levels of PCT are found to be higher in bacterial infections in comparison to viral infections and non-specific inflammatory diseases.
- Plasma procalcitonin concentration in healthy calves and those with septic systemic inflammatory response syndrome
- Cell-Free DNA, High-Mobility Group Box-1, and Procalcitonin Concentrations in Dogs With Gastric Dilatation-Volvulus Syndrome
- Biomarker Guided Diagnosis of Septic Peritonitis in Dogs
- Procalcitonin Detection in Veterinary Species: Investigation of Commercial ELISA Kits
Troponin
This is a biomarker that is found in the blood when heart muscles become damaged and as the damage increases the levels of troponin increase.
SAA Canine
This is a biomarker for tissue injury and many inflammatory diseases and increases in response to tissue damage or inflammation.
Haptoglobin Canine
Serum haptoglobin levels increase with most types of inflammation in dogs. However, sustained elevated haptoglobin is seen in canine lymphatic neoplasms. This makes haptoglobin a particlarly good biomarker for monitoring remission and recurrence in these cancers.
Haptoglobin Feline
Similar to dogs, serum haptoglobin in cats has been used to monitor treatment and remission of chronic gastric enteropathies, including alimentary lymphoma and inflammatory bowel disease.
AGP Feline
This biomarker increases in FCov-positive cats and can occur a few days before FIP becomes clinically apparent.
SAA Feline
This is a biomarker for tissue injury and many inflammatory diseases and increases in response to tissue damage or inflammation.
