RESUMO
BACKGROUND: Quantitative immunochromatographic strip (ICS) assay can facilitate clinical diagnosis by providing more information than traditional qualitative or semiquantitative strip assay. METHODS: We constructed a human serum alpha-fetoprotein (AFP) measurement system by combining semiquantitative ICS tests and artificial neural network (ANN) image analysis system [immunochromatographic strip analyzed by artificial neural network image analysis system (IAIS)]. After ICS tests completed, the AFP concentration can be obtained from analysis of IAIS software. The equipment required are commercial semiquantitative AFP dipstick, optical scanner, centrifuge (option), personal computer, and software of IAIS. RESULTS: The serum AFP concentrations measured by IAIS were strongly correlated (r = 0.9971) with that by RIA. Using Bland-Altman analysis, the IAIS achieved clinical acceptable limits of agreement in comparison with RIA. The within-run precision of IAIS, expressed as coefficients of variation (CV), at 81.7 ng/ml was 1.50% and, at 244.4 ng/ml, was 1.09%. The measurement of serum AFP by IAIS can be completed in 20 min. CONCLUSIONS: The newly constructed quantitative immunochromatographic strip assay (IAIS) is a simple, rapid, and reliable method for serum AFP measurement. With the simple equipment required, the IAIS can be performed outside the laboratory and is ideal for outpatient or point-of-care AFP testing.