Automatic and Simultaneous Analysis of Lens culinaris Agglutinin-Reactive α-Fetoprotein Ratio and Total α-Fetoprotein Concentration

Abstract

An automated analytical method for analyzing alpha-fetoprotein (AFP) carbohydrate chain microheterogeneity based on competitive reaction between lectin and anti-AFP monoclonal antibody in liquid phase is described. The antibody used binds to all species of AFP molecule without Lens culinaris agglutinin (LCA); however, its binding reaction to LCA-reactive AFP was inhibited by LCA. Sulfated tyrosine octamer was conjugated to the antibody, and sulfated tyrosine pentamer and peroxidase were conjugated to other monoclonal antibodies, respectively. Serum reacted with three anti-AFP monoclonal antibodies and LCA in liquid phases, and two types of immune complex were observed. The two types were separated directly by the liquid-phase binding assay system equipped with an anion-exchange column. Peroxidase activity of immune complex was determined fluorophotometrically. Total AFP concentration and the ratio of LCA-reactive AFP in samples were calculated simultaneously, using the sum of the two peaks and the ratio of peaks obtained by LCA inhibition to sum of two peaks. The results correlated well with conventional methods. The method is simple and convenient for routine clinical assays.

The War on Heterophilic Antibody Interference

“…Although we do not consider removal of immunoglobulins as the preferred solution, there are possibilities for automation of milder methods. We have seen an automated instrument combining chromatography and immunoassay for the analysis of ␣-fetoprotein with different glycosylations (14 ). Such an instrument may be modified for the preanalytic removal of immunoglobulins.…”

Tumor Markers in Early Diagnosis, Follow-Up and Management of Patients with Hepatocellular Carcinoma

“…Thereafter, the percentage of AFP-L3 (AFP-L3%) is calculated by an equation: (area for AFP-L3 band)/(area for the total AFP band) ϫ 100% [1][2][3]. Recently, an automated method was developed in which the AFP-L3 fraction and total AFP are determined simultaneously [13]. The cutoff AFP-L3 value was set at 10%; values exceeding 10% are strongly suspected of reflecting HCC even when the total AFP value is increased only slightly.…”

The clinical utility of Lens culinaris agglutinin-reactive thyroglobulin ratio in serum for distinguishing benign from malignant conditions of the thyroid

“…In our previous study, heterogeneity of the carbohydrate chains on Tg from thyroid tissues was investigated using LCA, and LCA-reactive Tg ratio for thyroid carcinoma tissues was significantly lower than those for normal, Graves' disease, and benign tumor tissues [25]. LCA-reactive AFP has been used as an aid of diagnosis of hepatocellular carcinoma, and has been was measured competitive assay between LCA and anti-AFP monoclonal antibody [23][24].…”

“…s Lens culinaris agglutinin (LCA)-reactive α-fetoprotein (AFP) has been used as an effective marker for earlier diagnosis, assessment of therapeutic effect on and prognosis of hepatocellular carcinoma [19][20][21][22]. Measurement of LCA-reactive AFP has been carried out by competitive reaction between LCA and anti-AFP monoclonal antibody [23][24].…”