The application of epitope mapping in the development of a new serological test for Helicobacter pylori infection.
Epitope mapping was applied to the derived amino acid sequences of the urease A and urease B genes of Helicobacter pylori. This identified 15 epitopes of which five were the most immunodominant. These were LTPKELD (Ure A), FISP, QIPTAF, EVGKVA and SIP (Ure B). Peptide 1 representing LTPKELD and peptide 2 representing EVGKVA were used to develop ELISA procedures for detecting antibody specific to H. pylori infection. The sensitivity, specificity and efficiency values for peptide 1 reactive IgM were 31.6, 92.8 and 52.5% and for peptide 1 IgG were 52.6, 35.7 and 45.4%. The corresponding values for peptide 2 IgM were 31.6, 100 and 60.6% and for peptide 2 IgG were 63.2, 71.4 and 66.6% respectively. When the tests were combined so that a positive for either peptide was counted as a positive overall the figures for IgM were 52.6, 92.8 and 69.6%. Thus epitope mapping delineated peptides against which specific IgM was produced in active H. pylori infection.
Burnie
J P
JP
Manchester Royal Infirmary, UK.
al-Dughaym
A
A
D000907:Antibodies, Bacterial / Q000097:blood*; D001483:Base Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D012698:Serologic Tests; D014510:Urease / Q000276:immunology*
D000907:Antibodies, Bacterial; D014510:Urease