New monoclonal antibody-based test for Helicobacter pylori urease in gastric tissue

BACKGROUND/AIMS: To evaluate a new monoclonal antibody for Helicobacter pylori urease in gastric tissue. METHODS: A total of 107 volunteers were enrolled. All subjects underwent a 13C-urea breath test and esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia. Six biopsy specimens in the gastric antrum and body were obtained for a rapid urease test and histology. The new monoclonal antibody-based H. pylori urease test (HPU) was performed to rapidly and qualitatively detect urease in two biopsy specimens. RESULTS: H. pylori infection was diagnosed in 73 subjects. The sensitivity and specificity of the HPU was 89% and 74%, respectively. The subjects were divided into two groups: one with true-positive and true-negative HPU results (n = 90) and the other with false-positive and false-negative HPU results (n = 17). Across all subjects, ammonia levels were 900.5 +/- 646.7 and 604.3 +/- 594.3 mumol/L (p > 0.05), and pH was 3.37 +/- 1.64 and 2.82 +/- 1.51 (p > 0.05). Sensitivity was higher in the presence of atrophic gastritis or intestinal metaplasia. CONCLUSIONS: HPU detected H. pylori in approximately 10 min. Gastric aspirate ammonia and pH levels did not affect the test results. Sensitivity was good in the presence of atrophic gastritis or intestinal metaplasia.

Detection of Helicobacter pylori in Gastric Aspirates Using a Monoclonal Antibody-Based Test

BACKGROUND/AIMS: The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans. METHODS: Sixty-one volunteers were enrolled in the study. All of the subjects underwent a 13C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation. RESULTS: Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77+/-1.77 vs 3.49+/-1.30, p<0.05) and ammonia level (1,130.9+/-767.4 vs 184.2+/-126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively. CONCLUSIONS: The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates.

Culture and Polymerase Chain Reaction of Helicobacter pylori from Rectal and Terminal Ileal Fluid after Polyethylene Glycol (Colyte(R)) Ingestion in Healthy Adults with Positive Urea Breath Test / 대한소화기학회지

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) transmission route is not yet clearly understood. Isolating H. pylori from stool, saliva, and vomitus is very difficult. However, H. pylori could be cultured from feces in the setting of rapid gastrointestinal tract transit. The aim of this study was to isolate H. pylori by culture and PCR in the rectum and terminal ileum during colonoscopy. METHODS: Twenty subjects with positive UBT (urea breath test) were included. We performed polymerase chain reaction (PCR) test and culture of H. pylori with the rectal fluid and terminal ileal fluid during colonoscopy. RESULTS: H. pylori was cultured with rectal fluid from 9 (45.0%) of 20 subjects and with ileal fluid from 11 (55.0%) of 20 subjects. H. pylori was a little more frequently cultured from the terminal ileal fluid than the rectal fluid without statistical significance (p>0.05). PCR test detected flaA (16/20, 80.0% and 17/20, 85.0%), 16S rRNA gene (16/20, 80.0% and 17/20, 85.0%), cagA (10/20, 50.0% and 12/20, 60.0%), and ureC (9/20, 45% and 11/20, 54.5%) from the rectal fluid and the terminal ileal fluid, respectively. The specificity and sensitivity of ureC were 100%. CONCLUSIONS: H. pylori could be cultured from the rectal fluid and terminal ileal fluid in the setting of rapid gastrointestinal tract transit. These results suggest of fecal-oral transmission of H. pylori.

Comparative Sensitivity of ARCHITECT Syphilis TP with Other Antibody Tests / 임상검사와정도관리

BACKGROUND: Serological tests detecting antibodies specific to antigens of Treponema pallidum are useful tools for diagnosis and screening of syphilis. Nevertheless, conventional non-treponemal tests, which are commonly being used thanks to their low cost, have limited consistency in procedures and interpretations because of lack of automation. Moreover, they have innate lower sensitivity and specificity. Therefore, clinical use of non-treponemal tests has been significantly substituted by more reliable treponemal antibody assays. Considering such trend, diagnostic sensitivity of a recently introduced automatic chemiluminescent immunoassay, ARCHITECT Syphilis TP (Abbott Japan, Tokyo, Japan), was evaluated with comparison to existing methods to validate its clinical sensitivity. METHODS: Fifty stored sera with reactive results on a non-treponemal syphilis test done by requests from the attending physicians were collected consecutively. Diagnosis of syphilis was confirmed when two or more positive results were obtained among 3 treponemal antibody tests, a hemagglutination, an automated latex turbidimetry and ARCHITECT Syphilis TP. RESULTS: All 50 sera were confirmed as syphilis-infected. Diagnostic sensitivity of ARCHITECT Syphilis TP was estimated to 100%, whilst that of the hemagglutination and the latex turbidimetry was 94% and 98%, respectively. Correlation coefficient between S/COs of ARCHITECT Syphilis TP and quantitative results on the latex turbidimetry was caculated as 0.865. Compared to the hemagglutination titers, better quantitative correlation was observed with S/COs of ARCHITECT Syphilis TP. CONCLUSIONS: ARCHITECT Syphilis was thought to be a reliable test with good sensitivity and its automated feature was thought to be additionally beneficial. Although it is being used for a qualitative purpose, it seemed possible to expand its utility into quantitative use considering its acceptable quantitative correlation with the hemagglutination assay as well as the automated latex turbidimetric assay.

Comparative Sensitivity of ARCHITECT Syphilis TP with Other Antibody Tests / 임상검사와정도관리

BACKGROUND: Serological tests detecting antibodies specific to antigens of Treponema pallidum are useful tools for diagnosis and screening of syphilis. Nevertheless, conventional non-treponemal tests, which are commonly being used thanks to their low cost, have limited consistency in procedures and interpretations because of lack of automation. Moreover, they have innate lower sensitivity and specificity. Therefore, clinical use of non-treponemal tests has been significantly substituted by more reliable treponemal antibody assays. Considering such trend, diagnostic sensitivity of a recently introduced automatic chemiluminescent immunoassay, ARCHITECT Syphilis TP (Abbott Japan, Tokyo, Japan), was evaluated with comparison to existing methods to validate its clinical sensitivity. METHODS: Fifty stored sera with reactive results on a non-treponemal syphilis test done by requests from the attending physicians were collected consecutively. Diagnosis of syphilis was confirmed when two or more positive results were obtained among 3 treponemal antibody tests, a hemagglutination, an automated latex turbidimetry and ARCHITECT Syphilis TP. RESULTS: All 50 sera were confirmed as syphilis-infected. Diagnostic sensitivity of ARCHITECT Syphilis TP was estimated to 100%, whilst that of the hemagglutination and the latex turbidimetry was 94% and 98%, respectively. Correlation coefficient between S/COs of ARCHITECT Syphilis TP and quantitative results on the latex turbidimetry was caculated as 0.865. Compared to the hemagglutination titers, better quantitative correlation was observed with S/COs of ARCHITECT Syphilis TP. CONCLUSIONS: ARCHITECT Syphilis was thought to be a reliable test with good sensitivity and its automated feature was thought to be additionally beneficial. Although it is being used for a qualitative purpose, it seemed possible to expand its utility into quantitative use considering its acceptable quantitative correlation with the hemagglutination assay as well as the automated latex turbidimetric assay.

Telomerase Expression in Colorectal Tubular Adenoma Determined by Immunohistochemical Staining / 대한소화기학회지

BACKGROUND/AIMS: Telomeres are simple repeat elements located at each chromosome end of eukaryotic cells. The main function of telomeres is to cap the chromosome end and protect it from enzymatic attack. Telomerase that facilitates the synthesis of telomere has been detected in not only cancer but also precancerous lesion. In this study, we compared the telomerase expression between low grade and high grade colorectal tubular adenoma. METHODS: Among thissues from forty eight patients with colorectal tubular adenoma (23 low grade and 25 high grade colorectal dysplasia), telomerase expressions were evaluated by immunohistochemical staining. RESULTS: We classified 48 patients into two groups by the extent of nuclei staining pattern. High telomerase expression was a group which showed staining nucleus pattern above 50% in tubular adenoma. Low telomerase expression was a group which showed staining pattern nucleus below 50%. Twelve in 25 high grade colorectal dysplasia showed high telomerase expression (48%). Only one in 23 low grade colorectal dysplasia showed high telomerase expression (4%). Telomerase expression was much higher in the tissues from the patients with high grade than in those with low grade colorectal dysplasia (p<0.05). CONCLUSIONS: Activation of telomerase may be related to the malignant potential in colorectal epithelial cells. Further studies are needed to define the role of telomerase in colorectal tumorigenesis.