Analytical and Clinical Validation of a New Immunoenzymatic Method for the Measurement of Canine Parathyroid Hormone

Abstract

Renal hyperparathyroidism (RHPT) is one of the main complications in dogs affected with Chronic Kidney Disease (CKD). The measurement of serum parathyroid hormone (PTH) could be of clinical utility for the disease’s treatment and follow-up; however, PTH is not routinely determined due to limited available methods, often not fully validated in dogs. The aims of this study were the analytical validation of an immunoenzymatic method for the measurement of PTH in canine serum and the analysis of preliminary association of the obtained results with renal function. Twenty-six samples obtained from dogs healthy or affected with CKD were analysed. PTH was measured using a two-site immunoenzymometric human assay (ST AIA-PACK® Intact PTH, Tosoh Bioscience). The analytical validation protocol evaluated the assay precision and accuracy. Also, the PTH’s storage stability at 20 °C, 4 °C and −20 °C was assessed. Clinical validation was performed by comparing PTH values with creatinine, phosphorus and International Renal Interest Society (IRIS) stage. The method showed optimal precision and accuracy, whereas stability was adequate up to 4 h at 20 °C, 24 h at 4 °C and 6 months at −20 °C. PTH was positively associated with creatinine, phosphorus and IRIS stage. The investigated method was thus successfully validated in dogs, allowing its use for clinical purpose.

Analytical Validation of a New Immunoenzymatic Method for the Measurement of Feline Parathyroid Hormone in Cats with Chronic Kidney Disease

“…The measurement of PTH was performed after routine analyses using an automated analyser (AIA 360 ® ) and a two-site immunoenzymometric assay (ST AIA-PACK ® Intact PTH, Tosoh Bioscience, Tessenderlo, Belgium) validated in humans and dogs [ 12 ]. Briefly, the analysis is performed entirely in the test cups according to the procedure described.…”

Nutritional secondary hyperparathyroidism in a kitten, supported by immunoenzymatic measurement of feline intact parathyroid hormone

“…A standard curve is constructed" using 6 calibrators, and unknown sample concentrations are calculated using this curve. 21 This immunoenzymatic assay offers several advantages over radioimmunoassay: simple to perform without dedicated staff, total assay time of ~20 min, limited space requirement, and no need for radioactive materials. Calcitriol was quantified with a radioimmunoassay at the Michigan State University Veterinary Diagnostic Laboratory (Lansing, MI, USA).…”

“…The test has been validated in humans and in dogs and cats. 21,22 The test is performed entirely in a test cup; “intact PTH (iPTH) present in the sample is bound to a first polyclonal antibody immobilized on a magnetic solid phase and a second enzyme-labeled polyclonal antibody. The magnetic beads are washed to remove unbound enzyme-labeled polyclonal antibody and are then incubated with the fluorogenic substrate 4-methylumbelliferyl phosphate (4MUP).…”