Short-term follow-up by serology of patients given antibiotic treatment for Helicobacter pylori infection

Enzyme immunoassay and immunoblotting analysis of Helicobacter pylori infection in Turkish asymptomatic subjects

Approximately half of the world population is infected with Helicobacter pylori, particularly in developing countries. The aims of the study were to detect H. pylori infection in asymptomatic Turkish subjects, correlate the infection with the associated risk factors, and to evaluate the cytotoxin-associated gene (CagA) status and other H. pylori antigens. Three hundred nine asymptomatic subjects (124 female) 1-82 years of age (average: 31 years) were serologically tested by enzyme immunoassay and immunoblotting. The enzyme immunoassay detected IgG anti-H. pylori antibodies in sera of 216 (70%) out of 309 subjects, 132 (61%) male. Infection rates of 42% in subjects <10 years of age, 55% in 10-19 years, 66% in 20-29 years, 78% in 30-39 years, 79% in 40-49 years, 91% in 50-59 years, 100% in 60-69 years, and 80% in those >70 years of age were detected. Subjects >45 years of age had significantly higher antibody responses, odds ratio = 0.16 (95% confidence interval: 0.07-0.37), than those <45 years. H. pylori infection was significantly higher in married subjects, odds ratio = 0.38 (95% confidence interval: 0.20-0.73), and those with low socioeconomic status. No correlation between gender, education, smoking, and nonsteroidal anti-inflammatory drug intake and infection was detected. Immunoblots revealed antibodies to CagA in 58 (83%) of 70 samples tested. H. pylori infection is prevalent in the asymptomatic Turkish subjects. Marital and socioeconomic status was significantly associated with the acquisition of H. pylori. Antibodies to CagA antigen were highly prevalent in these subjects.

Prevalence of Helicobacter pylori infection in asymptomatic subjects in Libya

Helicobacter pylori infection is very common infection worldwide particularly in the developing countries. No detailed study on such infection is being recorded so far in Libya. The aims of the study were to detect H. pylori prevalence in asymptomatic Libyan subjects, to determine the rate of infection among different age groups and to correlate the prevalence of H. pylori with age, sex, smoking, non-steroidal anti-inflammatory drugs intake, marital status, education, and socioeconomic status. Three hundred and sixty asymptomatic subjects 1->70 years of age (average 36) with no previous history of epigastric pain were selected randomly from the Libyan population. Serum samples were obtained and a questionnaire was filled for each subject. The ELISA test was used to detect IgG anti-H. pylori antibodies. An overall prevalence of 76% was detected in these subjects. A 50% infection rate were in subjects 1-9 years of age that increased to 84% in subjects 10-19 years and continued with increasing age and reached up to 94% in those over 70 years of age. Subjects > 45 years of age had significantly higher antibody response than those <45 years. H. pylori prevalence was higher in married subjects (84%) as compared to singles (68%) and similarly in illiterates (89%) and low socioeconomic subjects (91%). No difference in sex, smoking and NSAIDs intake was recorded. Infection with H. pylori is highly prevalent in the Libyan asymptomatic subjects. Infection acquired early in childhood and reached up to 94% in older age. Prevalence of H. pylori was significantly increased in association with marital status, education and low socioeconomic status.

The use of serologic tests for the diagnosis of chlamydial infections

Serology is commonly used for the diagnosis of acute Chlamydia pneumoniae infections and also for the diagnosis of complicated Chlamydia trachomatis infections. Furthermore, recent sero-epidemiological studies have linked C. pneumoniae infection with several diseases traditionally considered non-infectious. The objectives of this mini-review are to critically review and discuss some selected analytical and methodological aspects, controversies and current problems in chlamydial serodiagnosis. To illustrate our views we present some original data of the comparison of current technologies. The review of the literature revealed high variability in methodologies applied to different studies. This observation was supported by our own data, which explains occasional conflicting clinical interpretation. Although the microimmunofluorescence (MIF) technique is generally considered as the gold standard for serodiagnosis of chlamydial infections, assay conditions are highly variable and hence pose a major problem in the interpretation of the results. For instance, many recent studies linking C. pneumoniae and atherosclerosis have utilized MIF techniques with variable threshold criteria for the positivity, in combination with selection bias of cases and controls possibly leading to conflicting results. Variability of assay conditions is also a common problem with Western blots, and interpretation is problematic when both anti-C. pneumoniae and anti-C. trachomatis antibodies are present. Furthermore, there is a lot of disagreement in serological criteria applied to recently emerged enzyme immunoassay (EIA) techniques when these assays are used for acute and non-acute clinical conditions and their association with Chlamydiae. In conclusion, standardization of serological techniques and the development of uniform criteria for interpretation of serologic findings is necessary to increase our knowledge of the biology of Chlamydiae, pathogenesis of any chlamydial infection and chronic infections in particular.

Use of a dry latex agglutination test to measure eradication of Helicobacter pylori infection

BACKGROUND AND METHODS

A total antibody latex serology test was compared with enzyme immunoassay serology after treatment for Helicobacter pylori infection in 22 patients.

RESULTS

Nineteen patients were cured of infection, but only nine (47%) were negative by the latex test after 6 months. However a significant decline in immunoglobulin (Ig)G was seen in 90% of the cured patients.

CONCLUSIONS

Although the latex test is suitable for initial diagnosis of H. pylori infection, it is not suitable for monitoring treatment success. A decline in IgG of more than 40% correlates well with successful eradication of H. pylori.