2019 Volume 68 Issue 3 Pages 470-475
We evaluated the basic performance of chemiluminescent immunoassay-based intact PTH assay, which was newly developed as part of the AIA-CL systems. The coefficients of variation (C.V.) of within-run and between-day precisions of the assay using quality control samples or pooled plasma from patients were 1.9 to 3.7% and 3.8 to 5.1%, respectively. Good linearity was observed from 0 to 5,000 pg/mL. The LoB, LoD, and LoQ were 0.19, 0.36, and 1.92 pg/mL, respectively. No interference by endogenous substances was noted. The relationship between AIA-1800 or cobas® 6000 and this method was good. The stability of serum in storage was poor at 4°C. Intact PTH concentrations were reduced by sample transfer to another container. This assay was only reactive against the 7–84 PTH fragment, and reactivity against the other PTH fragments (1–34, 13–34, 44–68, 39–68, 39–84, and 53–84) was below 0.1%. These results suggest that this method is useful for routine examinations, but caution is needed regarding sample stability and transfer.
