Analytical validation of the new version of the Liaison N-Tact PTH assay.

We performed analytical validation of the new version of the Liaison N-Tact PTH (parathormone) assay according to NCCLS guidelines and compared this new generation of reagent with the Roche Elecsys PTH assay. We showed that this new version is a sensitive and precise method with good recovery. Significant carryover was observed, but with limited clinical implications. We demonstrated that the new version of the Liaison PTH is in reasonably good agreement with the Roche Elecsys PTH assay, and as we observed no differences in a hemodialyzed population, moving from one method to the other should not affect the daily follow-up of patients. However, one should be cautious with the highest values (>500 pg/mL). We established reference intervals of 12-54 pg/mL for the Liaison and 14-52 pg/mL for the Elecsys assay.