Canine C-reactive protein measurements in cerebrospinal fluid by a time-resolved immunofluorimetric assay

Area of Science:

• Veterinary Medicine
• Immunology
• Biochemistry

Background:

• C-reactive protein (CRP) is a key biomarker for inflammation.
• Quantifying CRP in canine cerebrospinal fluid (CSF) is crucial for diagnosing neurological conditions.
• Existing methods may lack the sensitivity or precision required for CSF analysis.

Purpose of the Study:

• To adapt and validate a time-resolved immunofluorimetric assay (TR-IFMA) for measuring CRP concentrations in canine CSF.
• To assess the assay's performance characteristics, including sensitivity, precision, and linearity.
• To determine if the TR-IFMA can distinguish CRP levels in dogs with different clinical presentations.

Main Methods:

• Adaptation of a TR-IFMA for CRP quantification in canine CSF.
• Evaluation of intra- and interassay coefficients of variation.
• Assessment of assay linearity and correlation between CSF and serum CRP levels.
• Determination of the limit of detection for the TR-IFMA.

Main Results:

• The TR-IFMA demonstrated high precision with coefficients of variation below 15%.
• The assay showed a linear and proportional response (r = 0.99) to CRP concentrations.
• A significant correlation was found between CRP levels in CSF and serum (r = 0.80, P = 0.003).
• The limit of detection was 7.1 × 10⁻⁶ mg/l, and the assay differentiated CRP levels in dogs with inflammatory disorders versus other conditions.

Conclusions:

• The adapted TR-IFMA is a sensitive, precise, and accurate method for measuring CRP in canine CSF.
• This assay is suitable for clinical applications, enabling differentiation of CRP concentrations across various canine diseases.
• The TR-IFMA provides valuable diagnostic information for neurological and inflammatory conditions in dogs.