Serological differentiation of Helicobacter pylori CagA(+) and CagA(-) infections.
Many Helicobacterpylori strains causing gastroduodenal diseases have a cagA gene encoding CagA protein, a virulence factor of these bacteria. Anti-CagA antibodies produced by the majority of people infected with CagA(+) strains can indicate such an infection. In this study, the efficacy of three immunoenzymatic tests for detecting CagA(+) and CagA(-) infections were compared: immunoblot (Milenia ID Blot H. pylori IgG; MB) and ELISA conducted either with a recombinant immunodominant fragment of CagA (rCagA) or the full-length CagA molecule (flCagA). The 13C-urea breath test (13C-UBT) was used for establishing H. pylori status. The serum samples from 157 individuals were used for serodiagnosis. H. pylori CagA(+) infection was detected in H. pylori-infected individuals with similar frequencies by MB (64%) and flCagA-ELISA (60%) and a little less frequently by rCagA-ELISA (53%). There was a high coincidence between the negative results of these three tests for H. pylori-uninfected individuals with no anti-CagA IgG in the serum (96-100%). The results show that rCagA-ELISA and, especially, flCagA-ELISA are easy, inexpensive and useful noninvasive assays for the discrimination of CagA(+) and CagA(-) H. pylori infections in subjects examined by urea breath test.
Chmiela
Magdalena
M
Department of Immunology and Infectious Biology, Institute for Immunology and Microbiology, University of Lódź, Banacha 12/16, 90-237 Lódź, Poland. chmiela@taxus.biol.uni.lodz.pl
Wiśniewska
Monika
M
Bak-Romaniszyn
Leokadia
L
Rechciński
Tomasz
T
Płaneta-Małecka
Izabela
I
Bielański
Władysław
W
Konturek
Stanisław J
SJ
Płonka
Małgorzata
M
Klink
Magdalena
M
Rudnicka
Wiesława
W
D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005767:Gastrointestinal Diseases / Q000175:diagnosis / Q000276:immunology* / Q000382:microbiology*; D005798:Genes, Bacterial; D016481:Helicobacter Infections / Q000175:diagnosis / Q000276:immunology* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D012698:Serologic Tests; D014774:Virulence / Q000235:genetics
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori