A Strain-Specific Antigen in JapaneseHelicobacter pyloriRecognized in Sera of Japanese Children

Abstract

An enzyme immuno assay (EIA) test based on Japanese strain-derived high-molecular-weight cell-associated proteins (JHM-CAP) was evaluated by comparing with a previously developed EIA test based on a U.S. strain-derived high-molecular-weight cell-associated proteins (HM-CAP). Serum samples of 131 Japanese asymptomatic children (mean age, 5.5 years; range, 0 to 21 years) were tested that include 43 positive and 88 negative children as judged by Helicobacter pylori stool antigen test (HpSA test). Both tests showed comparable and reliable specificities, but the sensitivity of JHM-CAP EIA, at 93.0%, was much higher than that of HM-CAP EIA, at 67.4%. More false-negative results of HM-CAP were obtained in children under 10 years of age. Immunoblot analysis revealed that the JHM-CAP but not the HM-CAP preparation had a 100-kDa antigen recognized by JHM-CAP positive sera. It was concluded that JHM-CAP EIA is highly accurate for the serodiagnosis of H. pylori infection in Japanese young children and that the high sensitivity of JHM-CAP EIA in contrast to HM-CAP EIA is due to the presence of a 100-kDa antigen in Japanese strains that may be recognized by the host immune system at an early stage of infection.

Diagnostic accuracy of urine‐based kits for detection of Helicobacter pylori antibody in children

“…We have shown in a previous report that the sensitivity of a serum‐HpELISA kit, HM‐CAP, was only 51.4% (18/35) for children below 10 years compared to HpSA . However, an enzyme immunoassay test using serum samples based on Japanese strain‐derived antigens, JHM‐CAP, had significantly better performance than HM‐CAP, which is based on US strain‐derived antigens, in a study population of Japanese asymptomatic young children . Similarly, we reported that a urine‐HpELISA using H. pylori antigens derived from a Japanese strain had 94.4% sensitivity and 96.9% specificity with an accuracy of 96.0% in children .…”

Guidelines for the management of Helicobacter pylori infection in Japan: 2016 Revised Edition

“…In younger children, the risk for reinfection is high, and the sensitivity of an infection diagnosis using antibody measurement kits is low . In middle‐school students or older, the accuracy of antibody tests is equivalent to that in adults, and screening for infections is possible for students in middle school or older.…”

Proteomic Characterization of Helicobacter pylori CagA Antigen Recognized by Child Serum Antibodies and Its Epitope Mapping by Peptide Array

“…15 from a 4-year-old Japanese child with juvenile rheumatoid arthritis (Figure 1, Table S1 in Supporting Information). Japanese strains showed a distinct 130-kDa band of CagA which is highly immunoreactive as reported previously [17]. Among these, CPY2052, a low CagA producer was selected for 2-D immunoblot analysis, because large amounts of CagA of other strains might disturb the immunoblot analyses.…”