Evaluation of the Comparability of Commercial Ghrelin Assays

[摘要] Several assays are available to measure human ghrelin (h-GHS), but the comparability of results among assays is unknown. As an addition to previous investigations concerning the stability of h-GHS (1), it was our objective to compare the two most commonly used commercial h-GHS RIAs, focusing on side-by-side determinations, recoveries, and assay imprecision.The assays were purchased from Phoenix Pharmaceuticals (cat. no. RK-031-30) and Linco Research (cat. no. GHRT-89HK). Samples were stored at −80 °C and assayed as recommended by the manufacturers.For side-by-side comparisons, we used anonymized surplus sera (n = 151) from clinical studies of lean and obese individuals [mean body mass index (BMI), 26 kg/m2; range, 17–39 kg/m2]. Separate side-by-side comparisons were performed with 68 samples from two individuals (34/profile; BMI, 19.5 kg/m2) taken at 20-min intervals to evaluate the suitability of the assays for determining intraindividual changes. All participants gave informed consent.For recovery and imprecision studies, serum was collected from four males (27–33 years of age; no drug use; normal blood pressure; BMI, 22–24 kg/m2). Assay calibrators were added to achieve added concentrations of 100, 200, 400, or 800 ng/L. Each was measured 20 times. Recovery was calculated by subtracting the basal value of …

[学科分类] 过敏症与临床免疫学