Shinya Nagai

LecT-Hepa: A triplex lectin–antibody sandwich immunoassay for estimating the progression dynamics of liver fibrosis assisted by a bedside clinical chemistry analyzer and an automated pretreatment machine

BACKGROUND A quantitative analysis of glyco-alteration in serum glycoproteins provides glyco-parameters for estimating the progression of liver fibrosis. In the analysis of glycans, a manual pretreatment process for clinical specimens leads to a complicated manipulation and loss-of-clinical implementation of the assay. METHOD We evaluated an automated triplex lectin-antibody sandwich immunoassay assisted by an automated protein purification system (ED-01) and a bedside clinical chemistry analyzer (HISCL) for the acquisition of two glyco-parameters (AOL/DSA and MAL/DSA) derived from a fibrosis-related glyco-alteration of serum alpha1-acid glycoprotein (AGP). RESULTS We adjusted the auto-machines with their accuracy set to CV <5.0% (ED-01) and <1.0% (HISCL). AGP samples were enriched from 275 serum specimens. Two glyco-parameters obtained by HISCL showed a linear correlation with that from a reported assay (R>0.90). The formula for monitoring fibrosis (LecT-Hepa) was given by a combination of the glyco-parameters. This correlated with the fibrosis stage from biopsy (R=0.68) and diagnosed severe fibrosis and cirrhosis. It was superior to that of FIB-4 index. CONCLUSIONS We automated a multilectin-assisted immunoassay with an order of magnitude reduction of operation time without any loss-of-accuracy. LecT-Hepa is a reliable method to assess fibrosis-dynamics from moderate fibrosis to cirrhosis.

Detection of Anti-Human T-Lymphotropic Virus Type I Antibody in Whole Blood by a Novel Counting Immunoassay

BACKGROUND Assays to screen for and confirm the presence of the antibody for human T-lymphotropic virus type I (HTLV-I) are currently performed with serum or plasma. We developed and evaluated a new counting immunoassay (CIA) for the detection of HTLV-I antibody in whole blood, using recombinant and synthetic peptide antigens. METHODS We assessed the CIA for detection of HTLV-I antibody in whole blood and plasma. The CIA is an immunity-measuring method that combines latex agglutination with particle-counting technology. The numbers of agglutinated latex particles, single latex particles, and blood cells in a sample are measured based on differences in particle size between latex particles and blood cells. RESULTS The CIA and ELISA methods were in agreement for all 24 plasma samples tested, including those from 6 patients with HTLV-I-associated diseases, 6 HTLV-I carriers, and 12 HTLV-I antibody-negative individuals. The concordance between the ELISA (plasma) and the CIA (whole blood) for samples from 24 patients was 100%. The concordance between a particle agglutination method (plasma) and the CIA (plasma or whole blood) for 1065 patients was 99.5%. The concordance between results obtained for 1065 pairs of plasma and whole blood samples with the CIA method was 100%. HTLV-I antibody in whole blood was stable for 3 days after blood collection. With this CIA method, results were available within 15 min. CONCLUSIONS The CIA method can be used in screening for HTLV-I. The use of whole blood rather than serum or plasma reduces the sample volume and number of blood collections required, as well as assay time.