Effect of transport temperature on the Scantibodies total intact parathyroid hormone immunoradiometric assay using the RIAMAT-280

Abstract

Background Inadequate temperature affects the stability of intact parathyroid hormone (i-PTH) kits. Room temperature during transport modifies i-PTH results. Method Percent bound (%B/Bmax) and concentrations (pmol/L) of standards, controls (C1, C2) and pool from eight standard curves were divided into: group I (three curves from kits kept at room temperature for more than 48 h) and group II (five curves from kits kept at 2–8°C) during transport. i-PTH was measured using Scantibodies total i-PTH assay with RIAMAT-280. Results %B/Bmax for standards, C1 and C2 were significantly higher in group I versus II ( P = 0.04). %B/Bmax for the pool were significantly lower in group I ( P = 0.001). i-PTH pool concentration in group I was 51% lower (95% confidence interval, 47–53%, P = 0.001); differences were not significant for C1 ( P = 0.25) and C2 ( P = 0.57) in both groups. Conclusion Room temperature on i-PTH kit during transport alters the standard curve, resulting in a decrease in i-PTH. Using a pool as internal quality control allows the detection of these changes not detected by kit controls.