Radioimmunoassay, Parathyroid Hormone（CEW）

The potential for falsely depressed Intact PTH patient results at the low end of the assay range, less than or equal to 50 pg/mL (less than or equal to 5.3 pmol/L), when using specific lots identified by the firm on the IMMULITE 2000/IMMULITE 2000 XPi systems. The bias is observed in both serum and plasma samples.

Beckman Coulter has identified that some Access PTH reagent packs from lot 339071 may be over- or under-filled in well 0. The dispensed material in well 0 could be above or below specification, risking sealing issues, contamination, instrument errors, delays, or inaccurate results with a negative bias and increase in imprecision. The issue was confirmed on 10 April 2024 by Beckman Coulter through an internal non-conformance (NC-INT-66585). The well 0 scale on the filling line began malfunctioning on the fill immediately before PTH. The malfunction was not noticed until the majority of PTH was filled.

The reason for the recall is that EDTA and lithium heparin plasma samples that are stored in the DxI 9000 Access Immunoassay Analyzer sample wheel for a prolonged period before performing the intact PTH (parathyroid hormone) test may produce falsely decreased intact parathyroid hormone results. This could lead to a missed diagnosis, a delay in treatment, or inappropriate clinical management, depending upon the patient s clinical condition.

Due to an issue of high coefficient of variability (CV) problem caused by the accuspheres inside the Immunoassay kits.

Lower than expected iPTH patient and Quality Control (QC) results, reported negatively biased iPTH results- an average -12% shift in patient sample results

Potential for system to produce falsely elevated parathyroid hormone (PTH) results from patient samples.

Siemens is conducting this recall for the IMMULITE¿ 2000/IMMULITE¿ 2000 XPi Intact PTH (Intact Parathyroid Hormone) (iPTH) assay kit lot 320. Siemens has confirmed that IMMULITE¿ 2000/IMMULITE¿ 2000 XPi Intact PTH kit lot 320 can exhibit an average negative bias of up to -39% at iPTH concentrations <20 pg/mL with serum and EDTA patient samples vs. a reference kit lot.

There may be a loss of separation between Calibrators A and B which may impact the assay calibration at the lower end of the assay.

The device defect is a positive bias of up to 20% relative to the currently marketed Roche device. In addition, the firm states that during the investigation they discovered that the cleared reference interval (RI) was not set optimally at product launch in 2010 and that the upper limit in the IFU of 53.5pg/mL is too low and should be closer to 80 pg/mL. They are in the process of submitting the data to support the revised RI in a new 510K submission and will be changing the IFU once the 510K is cleared.

PTH Calibrator packaged with only high calibrator.

iPTH Assay- reagent and calibrator lots may have demonstrated higher than anticipated variability

iPTH Assay- reagent and calibrator lots may have demonstrated higher than anticipated variability