Helicobacter Pylori Antibodies Research Articles

Contribution of antibodies reacting with Campylobacter jejuni antigens in the testing of human sera for anti- Helicobacter pylori antibodies

The influence of antibodies that cross-react with Campylobacter jejuni antigens, in the testing of anti- Helicobacter pylori antibodies in human sera was evaluated. Sera (1 : 200) were tested for IgG antibodies in the enzyme-linked immunosorbent assay (ELISA) without ( H. pylori ELISA) and with ( H. pylori ELISA-Abs) preincubation with a C. jejuni sorbent. An H. pylori sonicate was used for coating. The mean absorbances (± sd; OD 405) with blood-donor sera were 0.39 ± 0.38 in ELISA, 0.25 ± 0.33 in ELISA-Abs ( P = 0.05), with positive ratings for 12 50 (24%) and 11 50 (22%) serum samples, respectively. Patients colonized by H. pylori showed mean absorbances (± sd) of 0.96 ± 0.38 (ELISA) and 0.69 ± 0.30 (ELISA-Abs), with positive ratings for 18 20 (90%) and 20 20 (100%) of samples, respectively. Antibodies in pooled serum from blood donors, bound to H. pylori antigens and then eluted, immunolabelled several H. pylori and C. jejuni antigens. In all probability, these included the H. pylori urease, the C. jejuni flagellar protein and a 43 kDa C. jejuni antigen, which formed a distinct band. The results indicate that cross-reacting antibodies contribute considerably to the antibody levels measured in the H. pylori ELISA. this contribution can easily be eliminated by resorting to the H. pylori ELISA-Abs which should improve the quality of the serodiagnosis of H. pylori colonization.

Increased prevalence of Helicobacter pylori antibodies among nurses

Increased prevalence of Helicobacter pylori antibodies among nurses

Increased Prevalence of Helicobacter pylori Antibodies Among Nurses

Numerous studies have suggested that Helicobacter pylori infection in asymptomatic subjects is transmitted from person to person. Its prevalence is higher in the institutionalized setting. If that is the case, persons involved in patient care should have a higher prevalence of the infection. We estimated the prevalence of H pylori antibodies among groups of asymptomatic medical and nursing staff and compared them with volunteer blood donors of similar age and sex. One hundred fifty-eight nurses and aides, 59 residents, 46 senior medical students, and 22 senior nursing students were enrolled in this study. Serum samples were tested for IgG antibodies against H pylori by enzyme-linked immunosorbent assay. Sixty-two (39%) of 158 nurses were found to be positive for antibodies to H pylori compared with 114 (26%) of 441 specimens from the blood donor group. Within the youngest age group (20 to 34 years), 13 (25%) of 51 nurses were positive for H pylori antibodies compared with 19 (13%) of 143 age-matched serum samples from the blood donor group. Within the middle age group (35 to 49 years), 32 (39%) of 83 nurses were positive for H pylori antibodies vs 43 (26%) of 167 age-matched blood donors. In the oldest age group (> 50 years), 17 (71%) of 24 nurses were positive for H pylori antibodies compared with 52 (40%) of 131 age-matched blood donors. Twenty-three (27%) of 86 nurses with 1 to 15 years of occupational exposure were positive for H pylori antibodies compared with 40 (56%) of 72 nurses with more than 15 years of occupational exposure. Nurses have an increased prevalence of H pylori antibodies that is significantly higher than the comparable prevalence of volunteer blood donors and is evident in the youngest age group. In addition, the increased prevalence is related to a longer duration of patient exposure in the nursing group.

Long-term omeprazole therapy does not affect Helicobacter pylori status in most patients.

Fifty-one patients were treated with 20-60 mg omeprazole for reflux oesophagitis resistant to H2-blocker therapy during a mean of 49 months of follow-up. With use of a standardized enzyme-linked immunosorbent assay technique specific IgG and IgG Helicobacter pylori antibodies were determined in serum obtained at the start of therapy and at the most recent visit. At the start of therapy 26 patients (51%) had evidence of H. pylori infection, as demonstrated by increased IgG and IgA antibody levels. During follow-up, 4 of these 26 patients (15%) became H. pylori seronegative. It is concluded that long-term treatment with omeprazole has no effect on H. pylori status in most patients.

Evaluation of the performance of commercial test kits for detection of Helicobacter pylori antibodies in serum.

We have compared the sensitivities, specificities, and predictive values of three commercial serological assays for the diagnosis of Helicobacter pylori infection. A qualitative latex method (Pyloriset; Orion Diagnostics), a semiquantitative enzyme-linked immunosorbent assay (ELISA) (GAP test IgG; Bio-Rad), and a quantiative ELISA (Helico-G; Porton Cambridge) were used in 109 untreated dyspeptic patients. The presence of H. pylori was established when the results of culture and/or histology of the gastric biopsies taken were positive. The prevalence of H. pylori infection was 62% (52% in 42 patients younger than 45 years of age and 69% in 67 patients older than 45 years of age). Sensitivities and specificities were 68 and 76% for Pyloriset, 89 and 77% for GAP test IgG, and 82 and 83% for Helico-G. The positive predictive values for all three tests were between 85 and 90%. The predictive values for the absence of disease with a negative result were 62, 82, and 74% for Pyloriset, the GAP test, and Helico-G, respectively. With Helico-G in the younger group (less than 45 years), sensitivity significantly lower (71 versus 87%) and a positive predictive value lower than those for the older group (greater than 45 years) were found. Either the sensitivities and specificities of commercial methods for the measurement of antibodies to H. pylori in serum must be improved or the relationship between the presence of antibodies and the presence of bacteria in the stomach at the time of investigation is too weak to allow the use of serological techniques instead of culture and histological investigation of gastric biopsy material.