Validation of an ELISA for detection of neutrophil gelatinase-associated lipocalin (NGAL) in equine serum.

This study aimed to validate the use of a porcine-specific ELISA test for detecting NGAL, a marker of kidney injury, in equine serum, and found it to be a reliable detection method in horses as well.

Objective of the Research

• The main aim of this research was to validate a commercially available porcine-specific ELISA (Enzyme-linked immunosorbent assay) for measuring serum concentrations of equine neutrophil gelatinase-associated lipocalin (NGAL). NGAL is known to be a promising marker of kidney injury in humans and dogs, but its description in horses has been lacking.

Methodology

• The researchers evaluated intra-assay (within the same assay) and inter-assay (between different assays) imprecisions by performing multiple measurements on equine serum pools.
• The accuracy of the assay was assessed through the linearity under dilution, essentially testing whether dilution of the sample affects the test results.
• They also tested the ability of the assay to differentiate between NGAL concentrations in horses with normal and elevated levels of serum creatinine, which is a waste product filtered by the kidneys. Higher creatinine levels can indicate kidney dysfunction.

Results

• The level of variation in the results (imprecision), both within and between assays, was found to be between 5.35% and 28.39%. This gives an indication of the variability of the results obtained from the ELISA.
• The validity of the test results was strong, with no signs of inaccuracy found in the assay.
• The assay could accurately detect the differences in NGAL levels in horses with normal and elevated serum creatinine concentrations, showing its ability to differentiate between varying levels of kidney function.

Conclusion

• The porcine-specific ELISA proved to be reliable in quantifying equine serum NGAL concentrations. The research, thus, successfully validated the use of this particular ELISA in the clinical serology of horses, especially for detecting kidney injury.