Evaluation of an immunoassay for determination of haptoglobin concentration in various biological specimens from swine

• Published in: American journal of veterinary research Vol. 70; no. 6; pp. 691 - 696
• Main Authors: Gutierrez, Ana M, Martinez-Subiela, Silvia, Ceron, Jose J
• Format: Journal Article
• Language: English
• Published: United States 01.06.2009
• Subjects: accuracy; Animals; biomarkers; blood serum; body fluids; chemical concentration; disease detection; fluorescent antibody technique; Fluoroimmunoassay - methods; Fluoroimmunoassay - veterinary; haptoglobins; Haptoglobins - metabolism; immunoassays; Male; meat inspection; meat juices; rapid methods; reference standards; saliva; Sensitivity and Specificity; serodiagnosis; Swine; Swine Diseases - metabolism; time-resolved immunofluorometry; validity
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.70.6.691

To develop and evaluate an immunoassay based on time-resolved immunofluorometry (TR-IFM) for measurement of haptoglobin concentrations in samples of various body fluids of swine. 20 pigs without clinical signs of disease and seronegative for antibodies against major viruses that affect pigs and 30 pigs with clinical signs of disease. Haptoglobin concentrations were measured in samples of serum, saliva, and meat juice obtained from both groups of pigs to evaluate the ability of TR-IFM to differentiate between healthy and diseased pigs. Performance of TR-IFM was evaluated by means of its calibration curve and detection limit, analytic precision during routine operation, and linearity of results for serial dilutions for the 3 types of samples. In addition, performance of TR-IFM was compared with that of a commercial spectrophotometric assay. The TR-IFM assay involved only 1 step, and the results were obtained in 20 minutes, with good analytic sensitivity and reproducibility. The analytic limit of detection was 0.52 ng/mL. Intra-assay and interassay coefficients of variation ranged from 1.13% to 4.81% and 5.97% to 13.57%, respectively. The method yielded linear results for all sample types. Serum haptoglobin concentrations determined by use of TR-IFM and spectrophotometric assays were highly correlated (r = 0.96). Differences between healthy and diseased pigs with respect to median haptoglobin concentrations were significant for all types of samples. The 1-step TR-IFM assay accurately quantified haptoglobin concentrations in serum, saliva, and meat juice samples from swine and may be useful in laboratory and meat inspection settings.