Validation of an automated immunoturbidimetric assay for feline serum amyloid A
Abstract Background Serum Amyloid A (SAA) is a major acute phase protein in cats, increasing rapidly in response to various inflammatory diseases. An automated latex-enhanced immunoturbidimetric assay for human SAA (LZ-SAA, Eiken), previously validated for use in cats, has had further major modifica...
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| Format: | Article |
| Language: | English |
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BMC
2022-09-01
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| Series: | BMC Veterinary Research |
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| Online Access: | https://doi.org/10.1186/s12917-022-03456-5 |
| _version_ | 1811253586714165248 |
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| author | Elspeth M. Waugh Hayley Haining James Harvie Alison E. Ridyard P. David Eckersall |
| author_facet | Elspeth M. Waugh Hayley Haining James Harvie Alison E. Ridyard P. David Eckersall |
| author_sort | Elspeth M. Waugh |
| collection | DOAJ |
| description | Abstract Background Serum Amyloid A (SAA) is a major acute phase protein in cats, increasing rapidly in response to various inflammatory diseases. An automated latex-enhanced immunoturbidimetric assay for human SAA (LZ-SAA, Eiken), previously validated for use in cats, has had further major modification (VET-SAA, Eiken) for specific use in veterinary diagnostic laboratories but has yet to be validated in cats. Results Intra-assay and inter-assay CVs for the VET-SAA assay ranged from 1.88–3.57% and 3.98–6.74%, respectively. Linearity under dilution was acceptable with no prozone effect observed. Limit of detection was 1.65 mg/L and limit of quantification was 6 mg/L. Haemoglobin and triglyceride showed no adverse interference, but bilirubin produced positive bias in samples with low SAA. Comparison with the LZ-SAA assay showed significant correlation with proportional bias increasing as SAA concentration increased, likely related to differing calibration standards. SAA was significantly higher in patients with inflammatory disease compared with non-inflammatory disease, and in patients with moderate to highly elevated α1-AGP compared with patients with normal α1-AGP. Improvement of the assay range may be required to fully evaluate differences between disease groups at low SAA levels. Based on ROC curve analysis, at a cut-off point of 20.1 mg/L the VET-SAA assay discriminated between inflammatory and non-inflammatory disease with sensitivity of 0.93 and specificity of 0.99. Conclusions The automated VET-SAA assay is a robust, precise, and accurate method for measurement of feline SAA which can clearly identify patients with inflammatory disease. It should be a valuable biomarker for use in feline medicine. |
| first_indexed | 2024-04-12T16:53:16Z |
| format | Article |
| id | doaj.art-e8cc8699b3ee4079959ac77189cb2074 |
| institution | Directory Open Access Journal |
| issn | 1746-6148 |
| language | English |
| last_indexed | 2024-04-12T16:53:16Z |
| publishDate | 2022-09-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Veterinary Research |
| spelling | doaj.art-e8cc8699b3ee4079959ac77189cb20742022-12-22T03:24:19ZengBMCBMC Veterinary Research1746-61482022-09-0118111010.1186/s12917-022-03456-5Validation of an automated immunoturbidimetric assay for feline serum amyloid AElspeth M. Waugh0Hayley Haining1James Harvie2Alison E. Ridyard3P. David Eckersall4Veterinary Diagnostic Services, School of Veterinary Medicine, University of GlasgowVeterinary Diagnostic Services, School of Veterinary Medicine, University of GlasgowVeterinary Diagnostic Services, School of Veterinary Medicine, University of GlasgowSmall Animal Clinical Services, School of Veterinary Medicine, University of GlasgowInstitute of Biodiversity, Animal Health and Comparative Medicine, University of GlasgowAbstract Background Serum Amyloid A (SAA) is a major acute phase protein in cats, increasing rapidly in response to various inflammatory diseases. An automated latex-enhanced immunoturbidimetric assay for human SAA (LZ-SAA, Eiken), previously validated for use in cats, has had further major modification (VET-SAA, Eiken) for specific use in veterinary diagnostic laboratories but has yet to be validated in cats. Results Intra-assay and inter-assay CVs for the VET-SAA assay ranged from 1.88–3.57% and 3.98–6.74%, respectively. Linearity under dilution was acceptable with no prozone effect observed. Limit of detection was 1.65 mg/L and limit of quantification was 6 mg/L. Haemoglobin and triglyceride showed no adverse interference, but bilirubin produced positive bias in samples with low SAA. Comparison with the LZ-SAA assay showed significant correlation with proportional bias increasing as SAA concentration increased, likely related to differing calibration standards. SAA was significantly higher in patients with inflammatory disease compared with non-inflammatory disease, and in patients with moderate to highly elevated α1-AGP compared with patients with normal α1-AGP. Improvement of the assay range may be required to fully evaluate differences between disease groups at low SAA levels. Based on ROC curve analysis, at a cut-off point of 20.1 mg/L the VET-SAA assay discriminated between inflammatory and non-inflammatory disease with sensitivity of 0.93 and specificity of 0.99. Conclusions The automated VET-SAA assay is a robust, precise, and accurate method for measurement of feline SAA which can clearly identify patients with inflammatory disease. It should be a valuable biomarker for use in feline medicine.https://doi.org/10.1186/s12917-022-03456-5Serum amyloid AAssayValidationFelineInflammationAcute phase protein |
| spellingShingle | Elspeth M. Waugh Hayley Haining James Harvie Alison E. Ridyard P. David Eckersall Validation of an automated immunoturbidimetric assay for feline serum amyloid A BMC Veterinary Research Serum amyloid A Assay Validation Feline Inflammation Acute phase protein |
| title | Validation of an automated immunoturbidimetric assay for feline serum amyloid A |
| title_full | Validation of an automated immunoturbidimetric assay for feline serum amyloid A |
| title_fullStr | Validation of an automated immunoturbidimetric assay for feline serum amyloid A |
| title_full_unstemmed | Validation of an automated immunoturbidimetric assay for feline serum amyloid A |
| title_short | Validation of an automated immunoturbidimetric assay for feline serum amyloid A |
| title_sort | validation of an automated immunoturbidimetric assay for feline serum amyloid a |
| topic | Serum amyloid A Assay Validation Feline Inflammation Acute phase protein |
| url | https://doi.org/10.1186/s12917-022-03456-5 |
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