scholarly journals Evaluation of Western Blot CagA Seropositivity in Helicobacter pylori-Seropositive and -Seronegative Subjects

2005 ◽  
Vol 12 (2) ◽  
pp. 304-309 ◽  
Author(s):  
J. Henrik Simán ◽  
Lars Engstrand ◽  
Göran Berglund ◽  
Claes-Henrik Florén ◽  
Arne Forsgren
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Positive Reaction ◽  
False Positive ◽  
Bimodal Distribution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Birth Cohorts ◽  
False Positive Reaction ◽  
Older Subjects ◽  
H Pylori

ABSTRACT CagA seropositivity is an important risk factor for gastric adenocarcinoma and duodenal ulcer. However, CagA seropositivity is also found in Helicobacter pylori-seronegative subjects. Is CagA seropositivity in these subjects a sign of a past H. pylori infection, or does it represent a false-positive reaction? This study investigates the intensity of the CagA immune reaction and the variation in CagA seroprevalence with year of birth for 650 subjects belonging to the Malmö Preventive Medicine cohort. CagA and H. pylori seroprevalences were determined by Western blot analysis (Helicoblot 2.1) and enzyme-linked immunosorbent assay. The peak intensity of the CagA band was significantly lower in H. pylori-seronegative subjects than in those with concomitant H. pylori seropositivity. In H. pylori-seropositive subjects, peak CagA intensity had a bimodal distribution. The prevalence of CagA-seropositive but H. pylori-seronegative subjects increased successively and significantly with year of birth, in contrast to the prevalence of CagA-seropositive and H. pylori-seropositive subjects, which decreased significantly. However, within H. pylori-seropositive and -seronegative subgroups, CagA seroprevalences were constant for different birth cohorts. If CagA seropositivity in H. pylori-seronegative subjects represents a past H. pylori infection, there must have been some mechanisms of eradication that were more common in younger subjects and that were of more importance than the presence of gastric atrophy and the longer duration and higher prevalence of H. pylori infection found in older subjects. Antibiotic treatment of H. pylori was not common practice at the time of enrollment. On the other hand, a false-positive reaction would be constant and independent of birth cohorts, as with the H. pylori-seronegative subgroup of our study. Peak CagA intensity in H. pylori-seronegative subjects corresponded to the lower part of the bimodal distribution of peak CagA intensity in H. pylori-seropositive subjects. We conclude that a major proportion of CagA seropositivity in H. pylori-seronegative subjects represents a false-positive reaction. Peak CagA intensity has a bimodal distribution in H. pylori-seropositive subjects. Low-intensity CagA seropositivity in H. pylori-seropositive subjects is indeterminate, representing both false-positive and true-positive reactions.

scholarly journals Helicobacter pylori-Specific Immune Responses of Children: Implications for Future Vaccination Strategy

2002 ◽  
Vol 9 (5) ◽  
pp. 1126-1128 ◽  
Author(s):  
Günter Bode ◽  
Isolde Piechotowski ◽  
Dietrich Rothenbacher ◽  
Hermann Brenner
Keyword(s):  
Helicobacter Pylori ◽  
Confidence Interval ◽  
Immune Responses ◽  
Western Blot ◽  
Vaccination Strategy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Significant Difference ◽  
Specific Igg ◽  
H Pylori

ABSTRACT We analyzed the specific anti-Helicobacter pylori immunoglobulin G (IgG) antibody profile for a sample of 824 asymptomatic schoolchildren in southern Germany (mean age, 10.7 ± 0.65 years) with an H. pylori-specific IgG enzyme-linked immunosorbent assay and Western blot analysis. The prevalence of infection was 19.8% (95% confidence interval, 17.1 to 22.7%). The immunoresponses were characterized predominantly by antibodies against low-molecular-mass antigens of 14 and 29 kDa, with a significant difference between children of German and Turkish nationalities (P = 0.0012 and P < 0.0001, respectively).

scholarly journals Helicobacter pylori Infection and Strain Types in Adult Dyspeptic Patients Undergoing Endoscopy in a Specialized Hospital of Dhaka City

2009 ◽  
Vol 3 (1) ◽  
pp. 4-9
Author(s):  
Sufi HZ Rahman ◽  
M Anisur Rahman ◽  
MS Arfin ◽  
M Mahbub Alam ◽  
TM Bhuiyan ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Helicobacter Pylori Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rapid Urease Test ◽  
Type I ◽  
Urease Test ◽  
H Pylori

Helicobacter pylori infection occurs worldwide with a high prevalence in developing countries. Virulence of H. pylori strains varies in different geographic regions. The aim of this study was to see H. pylori infection and its strain types in adult dyspeptic patients in Bangladesh and to analyze association of H. pylori strain types with clinical disease and severity of histological gastritis. Ninety consecutive adult dyspeptic patients undergoing diagnostic endoscopy were tested for H. pylori infection by culture, rapid urease test (RUT), histology and anti H. pylori IgG ELISA (Enzyme linked immunosorbent assay). H. pylori strain types were determined by Western Blot analysis. Association of strain types with clinical gastro-duodenal diseases and grades of histological gastritis were analyzed by χ2 test. Among the selected patients, 53 (58.9%) were culture positive, 48 (53.3%) were RUT positive, 31 (34.4%) were histology positive and 82 (91.1%) were anti-H. pylori IgG ELISA positive. By Western Blot analysis of the 90 sera samples, 48 (53.3%) showed antibodies to Type I strain of H. pylori, 21 (23.3%) Intermediate strain and 3 (3.3%) Type II strain. Endoscopically, 20 (22.2%) patients were found normal, 27 (30.0%) had gastritis, 9 (10.0%) had duodenitis, 28 (31.1%) had peptic ulcer disease, 4 (4.4%) had gastric carcinoma, and 2 (2.2%) had reflux esophagitis. Histologically, 34.4% had H. pylori, 44.4% had polymorhonuclear neutrophil (PMN), 100% had mononuclear cell (MNC) infiltration of different grades, 1.1% had atrophic gastritis and 2.2% had intestinal metaplasia of moderate grade. H. pylori strain types was not associated with clinical gastro-duodenal diseases or grades of PMN or MNC infiltration (p > 0.05) in these patients. Key words: Helicobacter pylori infection, H. pylori strain types, gastro-duodenal diseases, grades of gastritis   doi: 10.3329/bjmm.v3i1.2963 Bangladesh J Med Microbiol 2009; 03 (01): 4-9

scholarly journals Simultaneous Detection and Differentiation of Anti-Helicobacter pylori Antibodies by Flow Microparticle Immunofluorescence Assay

2004 ◽  
Vol 11 (1) ◽  
pp. 131-136 ◽  
Author(s):  
F. Bühling ◽  
G. Koch ◽  
T. Wex ◽  
A. Heimburg ◽  
M. Vieth ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Virulence Factors ◽  
Simultaneous Detection ◽  
Immunoblot Analysis ◽  
Measurement Range ◽  
Immunofluorescence Assay ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
H Pylori

ABSTRACT Helicobacter pylori is the key pathogen for gastroduodenal diseases. The clinical outcome of H. pylori infection is influenced by the presence of strain-specific virulence factors that are usually detected by the presence of specific anti-H. pylori antibodies in serum. Apart from the detection of these antibodies by enzyme-linked immunosorbent assay (ELISA), it is desirable to obtain additional information concerning the presence of certain virulence factors of H. pylori that are currently detected by immunoblot analysis. At present, the immunodiagnosis of an H. pylori infection includes two separate methods: ELISA and immunoblot analysis. Here, we report the development and evaluation of a new rapid flow microparticle immunofluorescence assay (FMIA) for detection of anti-H. pylori antibodies in human serum. The assay allows rapid qualitative and quantitative detection of anti-H. pylori antibodies by using crude antigen preparations as well as single recombinant antigens (urease A, urease B, CagA, and alkylhydroxy peroxide reductase) in the same sample with one measurement, and thus it combines the advantages of enzyme immunoassay and Western blot analysis. Seventy-five patient samples were analyzed by FMIA, ELISA, and Western blotting with respect to their immunoreactivity against crude H. pylori extracts and individual H. pylori antigens. Statistical analyses revealed an overall similarity of more than 90% among the results for FMIA, ELISA, and Western blot. Therefore, we conclude that FMIA is a powerful and time- and cost-saving assay system for the detection of antimicrobial antibodies, with higher sensitivity and a larger measurement range than ELISA.

scholarly journals A Novel Line Immunoassay Based on Recombinant Virulence Factors Enables Highly Specific and Sensitive Serologic Diagnosis of Helicobacter pylori Infection

2013 ◽  
Vol 20 (11) ◽  
pp. 1703-1710 ◽  
Author(s):  
Luca Formichella ◽  
Laura Romberg ◽  
Christian Bolz ◽  
Michael Vieth ◽  
Michael Geppert ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Immune Responses ◽  
Virulence Factors ◽  
Gastrointestinal Disease ◽  
Individual Risk ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Serologic Test ◽  
Content Type ◽  
H Pylori

ABSTRACTHelicobacter pyloricolonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome.H. pylorivirulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to importantH. pylorivirulence factors. This line immunoassay system (recomLine) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed inEscherichia coli, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) wereH. pylorinegative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), therecomLine assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, therecomLine assay provides a valuable tool for the diagnosis ofH. pyloriinfection.

scholarly journals False positive reaction due to endogenous biotin activity in glandular epithelium of decidua

2005 ◽  
Vol 36 (2) ◽  
Author(s):  
Liliana Cruz Spano ◽  
Paulo Roberto Merçon de Vargas ◽  
José Paulo Gagliardi Leite ◽  
Jussara Pereira do Nascimento
Keyword(s):  
Positive Reaction ◽  
False Positive ◽  
Glandular Epithelium ◽  
False Positive Reaction ◽  
Endogenous Biotin
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