Evaluation of the CLINITEST? Human Chorionic Gonadotropin (hCG) Pregnancy Test for Susceptibility to the Hook Effect by the hCG β Core Fragment

摘要

To the Editor:In a recent report in Clinical Chemistry , Nerenz et al. described a screening method to evaluate point-of-care human chorionic gonadotropin (hCG)1 devices for susceptibility to the hook effect by the hCG β core fragment (hCGβcf) (1). Among the 11 devices they evaluated was the CLINITEST? hCG pregnancy test. Nerenz et al. did not perform the testing for the CLINITEST hCG product themselves but opted to send screening samples to a colleague to perform the test on the CLINITEK? Status+ analyzer according to the manufacturer's instructions. The protocol required that the 3 screening samples be run in duplicate on a single instrument with 1 reagent lot. The results of this testing are shown in Table 1.View this table:Table 1. CLINITEST hCG performance screening method samples.The interpretation of these results by Nerenz et al. was that the test detected intact hCG at 5 × 102 pmol/L, detected hCGβcf at 5 × 105 pmol/L, and gave a false-negative and a borderline result for the sample containing 5 × 102 pmol/L intact hCG + 5 × 105 pmol/L hCGβcf, indicating that this sample is at or near the threshold of a combined hCG and hCGβcf high-dose hook …