Evaluación del analizador Delfia Xpress para el cribado prenatal de aneuploidías

Abstract

ObjectiveTo evaluate the Delfia Xpress analyzer reliability and practicability in all the techniques of first and second trimester prenatal screening. Materials and methodsThe Delfia Xpress (Perkin-Elmer, Wallac) is a biochemical immunoassay analyzer,that uses the Europium as specific fluorescent labelled marker and allows the determination of the first and second trimester parameters of the prenatal screening profile's: free β-human chorionic gonadotrophin (fβhCG) and pregnancy associated plasma protein-A (PAPP-A), alpha-fetoprotein (AFP), free-estriol (uE3), incorporating the Lifecycle v3.0® software for risk-prenatal calculation on-line with the laboratory compute system. First trimester combined screening test was performed on 3020 pregnant women and 678 on second trimester screening tests. ResultsConcerning its reliability, Delfia Xpress analyzer has shown a within and between day imprecision for the fβhCG and PAPP-A determinations below to 6%, proving the linearity and the correlation of its determinations. The analysis of the results of 3020 first trimester combined prenatal screening tests, shows a sensitivity in detecting Down‘s syndrome of 78.57% with a PPV (positive predictive value) of 11.58% with a 2.79% false positive. Eleven patients were diagnosed as carriers of Down‘s syndrome and two with Edwards syndrome. As for the practicability, the start up and operation of the analyzer are simple, and the stability of the calibration along with equitable cost for screening, makes the Delfia Xpress as an analyzer with a good relationships quality/cost. ConclusionsThe complete study has shown that Delfia Xpress is an analyzer with a high technical and clinical reliability, validating the instrument for processing the prenatal screening routine of our reference hospital.