Elecsys PTH

Catalog Number: 11972103160

SYSTEM INFORMATION

INTENDED USE

Immunoassay for the in vitro quantitative determination of intact parathyroid hormone in human serum and plasma for the differential diagnosis of hypercalcemia and hypocalcemia. This assay can be used intraoperatively.

STORAGE AND STABILITY

Store at 2‑8 °C.

CRITERION: METHOD COMPARISON SERUM VERSUS PLASMA, SLOPE 0.9‑1.1 + INTERCEPT WITHIN < ± 2 X ANALYTICAL SENSITIVITY (LDL) + COEFFICIENT OF CORRELATION > 0.95.

A comparison of the Elecsys PTH assay (y) with a commercial PTH test (x) using clinical samples gave the following correlations (pg/mL):

CALIBRATION

Traceability: This method has been standardized against a commercial PTH test (RIA).The recovery of the NIBSC 95/646 (WHO) standard was assessed by testing dilutions in human serum covering the measuring range (40‑4000 pg/mL) on 16 analyzers (cobas e 411 and cobas e 601 analyzers). The mean recovery was 100 % ± 4 %.

EVERY ELECSYS REAGENT SET HAS A BARCODED LABEL CONTAINING SPECIFIC INFORMATION FOR CALIBRATION OF THE PARTICULAR REAGENT LOT. THE PREDEFINED MASTER CURVE IS ADAPTED TO THE ANALYZER USING THE RELEVANT CALSET.

CALIBRATION INTERVAL MAY BE EXTENDED BASED ON ACCEPTABLE VERIFICATION OF CALIBRATION BY THE LABORATORY.

RENEWED CALIBRATION IS RECOMMENDED AS FOLLOWS:

CONTROLS FOR THE VARIOUS CONCENTRATION RANGES SHOULD BE RUN INDIVIDUALLY AT LEAST ONCE EVERY 24 HOURS WHEN THE TEST IS IN USE, ONCE PER REAGENT KIT, AND FOLLOWING EACH CALIBRATION.

LIMITS AND RANGES

Measuring range

MEASURING RANGE

1.20‑5000 pg/mL or 0.127‑530 pmol/L (defined by the Lower Detection Limit and the maximum of the master curve). Values below the Lower Detection Limit are reported as < 1.20 pg/mL (< 0.127 pmol/L). Values above the measuring range are reported as > 5000 pg/mL (> 530 pmol/L).

1.20‑5000 PG/ML OR 0.127‑530 PMOL/L (DEFINED BY THE LOWER DETECTION LIMIT AND THE MAXIMUM OF THE MASTER CURVE). VALUES BELOW THE LOWER DETECTION LIMIT ARE REPORTED AS < 1.20 PG/ML (< 0.127 PMOL/L). VALUES ABOVE THE MEASURING RANGE ARE REPORTED AS > 5000 PG/ML (> 530 PMOL/L).

LOWER LIMITS OF MEASUREMENT

Lower detection limit of the test

NOT NECESSARY DUE TO THE BROAD MEASURING RANGE.

SPECIFIC PERFORMANCE DATA

Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.

PRECISION

Precision was determined using Elecsys reagents and pooled human sera in a modified protocol (EP5‑A) of the CLSI (Clinical and Laboratory Standards Institute): 6 times daily for 10 days (n = 60); repeatability on MODULAR ANALYTICS E170 analyzer, n = 21. The following results were obtained:

PRECISION WAS DETERMINED USING ELECSYS REAGENTS AND POOLED HUMAN SERA IN A MODIFIED PROTOCOL (EP5‑A) OF THE CLSI (CLINICAL AND LABORATORY STANDARDS INSTITUTE): 6 TIMES DAILY FOR 10 DAYS (N = 60); REPEATABILITY ON MODULAR ANALYTICS E170 ANALYZER, N = 21. THE FOLLOWING RESULTS WERE OBTAINED:

INTERMEDIATE PRECISION

INTERMEDIATE PRECISION

PRECISION WAS DETERMINED USING ELECSYS REAGENTS AND CONTROLS IN A SEPARATE STUDY ACCORDING TO PROTOCOL EP5‑A2 OF THE CLSI (CLINICAL AND LABORATORY STANDARD INSTITUTE): 2 RUNS PER DAY IN DUPLICATE EACH FOR 21 DAYS (N = 84). THE FOLLOWING RESULTS WERE OBTAINED:

INTERMEDIATE PRECISION

INTERMEDIATE PRECISION

METHOD COMPARISON

A comparison of the Elecsys PTH assay (y) with a commercial PTH test (x) using clinical samples gave the following correlations (pg/mL):

ANALYTICAL SPECIFICITY

No cross‑reactivities were found for: Osteocalcin, PTH fragment 1‑37, PTH‑related protein (1‑86), bone‑specific alkaline phosphatase, and β‑CrossLaps.

THE FUNCTIONAL SENSITIVITY IS THE LOWEST ANALYTE CONCENTRATION THAT CAN BE REPRODUCIBLY MEASURED WITH AN INTERMEDIATE PRECISION CV OF ≤ 20 %.