Isolation and preliminary evaluation of a low-molecular-mass antigen preparation for improved detection of Helicobacter pylori immunoglobulin G antibodies

Abstract

Previously, immunoglobulin G (IgG) antibodies to five antigens with a relative molecular mass of between 15 and 30 kDa from Helicobacter pylori were found to be significantly more frequent in H. pylori-infected patients than in noninfected patients. In this study, these specific low-molecular-mass (LMW) antigens were separated by ultrafiltration of whole-cell sonicates. The LMW antigen preparation was evaluated by enzymelinked immunosorbent assay with serum samples from 76 children with abdominal symptoms and 151 adults with dyspeptic symptoms. H. pylori was cultured or seen in 40 (53%) children and 83 (55%) adults. Increased antibody levels to H. pylori were found in serum from 35 (46%) children and 88 (58%) adults. Values for sensitivity, specificity, and predictive value of positive and negative results of the test were higher with LMW antigens than with the heat-stable antigen previously described. The low specificity and predictive value of a positive result were due to seropositive results for 21 persons with a negative culture for H. pylori and negative microscopy results for Helicobacter-like organisms in biopsies from gastric mucosa. Histologically, chronic gastritis was demonstrated in 43% of these persons, and 19% had peptic ulcer, indicating that they have or have had H. pylori infection. Specific antibodies to H. pylori were confirmed in all 21 patients by the Western immunoblot technique. Use of the LMW antigen improved the IgG antibody detection in patients with H. pylori infection, even though the results reflect the difficulties in establishing a true gold standard for diagnosis of H. pylori infection.

The Accuracy of Serologic Diagnosis of Helicobacter pylori Infection in School‐aged Children of Mixed Ethnicity

“…A recent French study of pediatric patients also found the highest concordance index for the 26 kDa band [30]. Andersen et al suggested a combination of the 19-36 kDa bands to identify H. pylori positive patients [31,32], which was supported by the high concordance indexes for the low molecular bands in our study and also in the French study [30].…”

Immune Response to a 26‐kDa Protein, Alkyl Hydroperoxide Reductase, in Helicobacter pylori‐Infected Mongolian Gerbil Model

“…We have reported the serum immunoglobulin G immune reaction to H. pylori crude antigens in gerbil models with the early and advanced stages of H. pylori infection [20]. The results with gerbils appear to correlate with results obtained from humans [13,14,23]. The antibody response in-patient with H. pylori infection includes a response to high-molecular proteins (110/120 kDa), medium-size proteins (43-66 kDa) and low-molecular-mass proteins (26,29,30,31 and 33 kDa).…”

“…In recent years, serological studies have shown that patients with H. pylori infection develop elevated levels of specific anti-H. pylori antibodies, and several antigens specific for H. pylori have been identified [11][12][13][14][15]. Using serum from the H. pylori -infected Mongolian gerbils model [16,17], which mimics human disease [18,19], we have reported the serum immune response and screened for H. pylori antigens [20] in this model.…”

“…The 30-kDa protein has also been described as a H. pylori-specific surface-exposed protein [26]. The 26-kDa cell surface protein has been suggested to be antigenically unique to H. pylori [13].…”

Helicobacter pyloriantibodies and gastric cancer: a gender-related difference

“…History of dyspepsia, peptic ulcer or other gastrointestinal disease, smoking and alcohol intake habits was recorded. The control group consisted of 110 age-and sex-matched in-patients (56 females and 54 males; median age, 57.2; range, 30-89 years), admitted to Kaunas Medical University Hospital and Vilnius Oncology Centre for illnesses unrelated to gastrointestinal disorders: diabetes mellitus (21), miscellaneous gynaecological disorders (23), osteoporosis (3), pneumonia (10), hemiparesis (14), glaucoma (16), cataract (11), coronary heart disease (12). Tumour staging was based on the histopathological (pTNM) classification system [9].…”