Performance of the Fully Automated Progesterone Assays on the Abbott AxSYM® and the Technicon Immuno 1® Analyser Compared with the Radioimmunoassay Progesterone MAIA®

Objective: Test performance of two automated progesterone assays available on the immunoassay analysers Abbott AxSYM® and Technicon Immuno 1®, respectively, was evaluated in comparison with the radioimmunoassay Progesterone MAIA®. Methods: For assessment of test performance imprecision, functional sensitivity and linearity of dilution was examined. Correlation with the manual radioimmunoassay was assessed using 122 serum samples over the range 0–110 nmol/L. Results: Imprecision studies revealed for the AxSYM Progesterone within-run CV’s of 1.8–6.4% and day-to-day CV’s of 3.5–9.7% (concentration range 2.3–75 nmol/L); Immuno 1 Progesterone: within-run CV’s 1.0–7.3%, day-to-day CV’s 2.3–7.7% (concentration range 1.2–60 nmol/L). The functional sensitivity was <1.7 nmol/L for the AxSYM Progesterone and <1.1 nmol/L for the Immuno 1 Progesterone. With the AxSYM Progesterone the mean recovery after dilution from five samples was 102% (89–107%), from one sample only 69–80% was recovered; with the Immuno 1 Progesterone the mean recovery was 95% (80–105%). Despite of a quite good overall correlation (coefficients 0.972 and 0.981) the relationship of both assays to the Progesterone MAIA significantly deviate from linearity with a considerably higher slope within the lower concentration range. The relationship between the automated assays was linear over the entire concentration range (Immuno = 1.207 * AxSYM + 1; r = 0.986). The time to first result was 20 min for the AxSYM Progesterone, 45 min for the Immuno 1 Progesterone and 90 min for the Progesterone MAIA. Conclusion: The evaluated progesterone assays both exhibit an excellent precision and a high degree of sensitivity. They offer a rapid and flexible method for progesterone determination which may be especially useful for the monitoring of ovarian stimulation during in-vitro fertilization.