Evaluation of nephelometry for albumin measurement in serum and cerebrospinal fluid: experiences with an indwelling subarachnoidal catheter system for repetitive cerebrospinal fluid collection in horses.

This research compares two methods for measuring albumin concentrations in horse serums and cerebrospinal fluids: one method involves total protein measurement followed by electrophoresis, and the other uses nephelometry. The study showed that both methods were highly correlated, but nephelometry was selected for its practicality. The researchers also experimented with a new technique for collecting consecutive cerebrospinal fluid samples using an indwelling catheter, evaluating the health of the horses through routine cytological analysis and daily clinical assessment.

Research Methods

• The team compared two techniques for calculating albumin concentrations in horses’ cerebrospinal fluid (CSF) and serum. The albumin quotient (AQ) was determined by both:
  • Measuring total protein, followed by electrophoresis of the samples to obtain an albumin percentage
  • Quantifying albumin immunoprecipitation through nephelometry
• The two methods were compared to determine which one is more reliable. The research showed high correlation in the results produced by the two methods, highlighting the effectiveness of both methods.
• They chose to use nephelometry for other albumin tests due to its practicality and effective results.

Implementation of a new technique

• The research team also used an indwelling subarachnoidal catheter, a new tool for collecting repetitive CSF samples from horses, reducing the need for multiple invasive procedures.
• To ensure the horses’ well-being, researchers performed routine cytological CSF examination and daily clinical evaluations.

Findings

• The subarachnoidal catheter was placed in two horses for periods of 14 and 17 days. Throughout this time, the health of the horses was maintained.
• One horse showed pleocytosis (an increased number of cells) in its CSF on two occasions; however, AQ values only increased significantly once.
• The other horse presented normal cell count in CSF, even though there were two abrupt changes in its AQ value. Despite these changes, the AQ stayed within the 95% confidence interval for horses.
• The study concludes that nephelometry is an effective method for measuring albumin in horse serum and CSF samples. Moreover, the use of an indwelling subarachnoidal catheter system appears to be a viable way to collect serial CSF samples from horses, providing a less invasive alternative to repeated centesis.