Evaluation of a Semi-Quantitative Lateral Flow Device for Serum Amyloid A in Healthy and Otostrongylus-Infected Juvenile Northern Elephant Seals (Mirounga angustirostris)
Acute phase proteins have been demonstrated to be valuable tools in the detection of underlying inflammatory processes in numerous species.2 Previously, the diagnostic utility of serum amyloid A (SAA) has been shown in stranded juvenile northern elephant seals (Mirounga angustirostris),3 which was measured using an immunoturbidimetric (IT) assay (SAA-1)a that is best implemented at the reference laboratory. The objective of the current study was to examine the diagnostic use of a semi-quantitative commercial lateral flow device (LFD)b to the IT assay.1 Twenty-five samples from healthy animals with a median of 12.1 mg/L SAA (95% CI 3.4–14.4, range 0.1–45.0) all tested within normal limits by LFD (e.g., three lines). Twenty-two samples from animals with clinical signs of Otostrongylus infection and a median IT SAA of 328.0 mg/L reflected either moderate (two lines, n=4) or high (one line, n=18) levels by the LFD. Three samples representing low, moderate, and high SAA levels were subject to repeated measures (n=6) and the results were in agreement by visual assessment. Similar to the SAA-1 reagent, the antibody used in the LFD appears to cross-react well with SAA from the northern elephant seal. Thus, the LFD may provide an opportunity for quick patient side assessment for inflammation. Initial assessment using the LFD device and submission to a reference laboratory for additional quantification using the IT SAA assay is recommended.
aSAA-1, Eiken, Tokyo, Japan
bLFD, OmniChek, Accuplex, Kildare, Ireland
The authors thank the staff and volunteers at the TMMC for collecting and organizing these samples. Authors also thank the laboratory staff at the University of Miami for technical support. All events were performed under the Stranding Agreement between NOAA’s National Marine Fisheries Service (NMFS) West Coast Region (WCR) and the Marine Mammal Center (TMMC).
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