Relationship between tobacco, cagA and vacA i1 virulence factors and bacterial load in patients infected by Helicobacter pylori.

BACKGROUND AND AIM: Several biological and epidemiological studies support a relationship between smoking and Helicobacter pylori (H. pylori) to increase the risk of pathology. However, there have been few studies on the potential synergistic association between specific cagA and vacA virulence factors and smoking in patients infected by Helicobacter pylori. We studied the relationship between smoking and cagA, vacA i1 virulence factors and bacterial load in H. pylori infected patients. METHODS: Biopsies of the gastric corpus and antrum from 155 consecutive patients in whom there was clinical suspicion of infection by H. pylori were processed. In 106 patients H. pylori infection was detected. Molecular methods were used to quantify the number of microorganisms and presence of cagA and vacA i1 genes. A standardized questionnaire was used to obtain patients' clinical data and lifestyle variables, including tobacco and alcohol consumption. Adjusted Odds Ratios (ORadjusted) were estimated by unconditional logistic regression. RESULTS: cagA was significantly associated with active-smoking at endoscope: ORadjusted 4.52. Evidence of association was found for vacA i1 (ORadjusted 3.15). Bacterial load was higher in active-smokers, although these differences did not yield statistical significance (median of 262.2 versus 79.4 copies of H. pylori per cell). CONCLUSIONS: The association between smoking and a higher risk of being infected by a virulent bacterial population and with higher bacterial load, support a complex interaction between H. pylori infection and environmental factors.

Quantification of Helicobacter pylori in gastric mucosa by real-time polymerase chain reaction: comparison with traditional diagnostic methods.

The aim of this study was to determine the main diagnostic validity parameters of a quantitative real-time polymerase chain reaction (PCR) system for detecting Helicobacter pylori in gastric biopsies. Prospective study. The real-time PCR has an internal control for eliminating the false negatives. Our system has a good diagnostic capacity compared with the gold standard and was superior in antral mucosa: area under the curve was 0.91 for antrum (95% confidence interval [CI] 0.87 to 0.96) and 0.83 for corpus (95% CI 0.77 to 0.9). The optimum cut-off point was 3.56 microorganisms/cell for antrum (sensitivity 83.5% [95% CI 74.2 to 89.9]; specificity 91.3% [95% CI 82.3 to 96.0]; positive predictive value 92.2%; negative predictive value 81.8%). The positive likelihood ratios were 9.61 and 8.52 for antrum and corpus, respectively. With the cut-off point that maximises the Youden index, 8.7% false positives were obtained. Our methodology is useful for diagnosing infection due to H. pylori and the false positives detected probably correspond to patients who were actually infected but the infection was not detected by traditional techniques. The clinical importance of these cases should be studied in greater detail since they may involve colonisations unrelated to the patient's digestive pathology.

Real-time PCR for diagnosing Helicobacter pylori infection in patients with upper gastrointestinal bleeding: comparison with other classical diagnostic methods.

The aim of this study was to determine the diagnostic usefulness of quantification of the H. pylori genome in detection of infection in patients with upper gastrointestinal bleeding (UGB). A total of 158 consecutive patients with digestive disorders, 80 of whom had clinical presentation of UGB, were studied. The number of microorganisms was quantified using a real-time PCR system which amplifies the urease gene with an internal control for eliminating the false negatives. A biopsy sample from the antrum and corpus of each patient was processed. The rapid urease test, culture, histological study, stool antigen test, and breath test were done. The gold standard was a positive culture or positive results in at least two of the other techniques. When a positive result was defined as any number of microorganisms/human cell, the sensitivity of real-time PCR was greater in bleeding patients, especially in the gastric corpus: 68.4% (95% confidence interval [CI], 52.3 to 84.5%) in non-UGB patients versus 91.5% (95% CI, 79.6 to 97.6%) in UGB patients. When a positive result was defined as a number of microorganisms/human cell above the optimal value that maximizes the Youden index (>3.56 microorganisms/human cell in the antrum and >2.69 in the corpus), the sensitivity and specificity in UGB patients were over 80% in both antrum and corpus. Our findings suggest that some bleeding patients with infection caused by H. pylori may not be correctly diagnosed by classical methods, and such patients could benefit from the improved diagnosis provided by real-time PCR. However, the clinical significance of a small number of microorganisms in patients with negative results in classical tests should be evaluated.

Does the use of a variable stiffness colonoscope offer advantages during colonoscopy under deep sedation? Results of a randomized trial.

INTRODUCTION: Variable stiffness colonoscope may be useful in performing colonoscopies in nonsedated patients or under endoscopist-controlled sedation. The objective of this study is to evaluate whether this instrument facilitates colonoscopy in patients under deep sedation monitored by an anaesthesiologist. METHODS: Prospective and randomized study enroling consecutive patients referred for colonoscopy under deep sedation monitored by an anaesthesiologist. In group I, a variable stiffness colonoscope was used, whereas in group II, a standard colonoscope was used. The main variable was the need to change the position of the patient during the endoscopy. RESULTS: Fifty-six patients were included in group I (variable stiffness colonoscope) and 54 in group II (standard colonoscope). The caecum was reached in 92.9% of patients in group I and in 90.7% of group II (P=0.7). The time required to reach the caecum was significantly less in group I (6.14±3.5 vs. 7.7±3.8; P=0.035). The variable stiffness colonoscope was effective in 66.7% of cases. Changing the position of the patient was necessary in 12.5% of cases in group I compared with 33.3% of cases in group II (P=0.01). CONCLUSION: The variable stiffness colonoscope avoids the need to change the patient's position and reduces caecal intubation time in patients undergoing colonoscopy under deep sedation controlled by an anaesthesiologist.

Gastrointestinal Hemorrhage Secondary to Duodenal Cystic Dystrophy in Heterotopic Pancreas.

Cystic dystrophy of the duodenal wall (CDDW) is a complication of heterotopic pancreatic tissue located in the wall of the gastrointestinal tract, characterized by the presence of multiple small cysts, usually found in the wall of the second part of the duodenum. Gastrointestinal hemorrhage due to CDDW is a rare complication. We report the case of a 50-year-old man who was admitted to our hospital for persistent vomiting. The imaging tests confirmed the diagnosis of CDDW. During his stay in hospital, the patient had a gastrointestinal hemorrhage secondary to this disorder, which made it necessary to perform a Roux-en-Y gastrojejunostomy (Billroth III).

Factors associated with non-attendance at outpatient endoscopy.

OBJECTIVE: Non-attendance at endoscopy procedures leads to wasted resources and increased costs. The purpose of this study was to investigate the factors associated with non-attendance. MATERIAL AND METHODS: All patients who attended the outpatient clinic for gastroscopy or colonoscopy examinations were included in the study. Patients who missed their appointment were identified and their data were collected prospectively. Patients who kept their appointment in the same period of time served as controls. RESULTS: Between August 2002 and February 2003, 1051 gastroscopies and 756 colonoscopies were scheduled. A total of 265 patients (14.7%) missed their appointment. No significant differences were found between attendees and non-attendees for mean age, gender, type of examination and day of the week on which the examination was scheduled. The time on the waiting list was longer in patients who did not keep their appointment than in those who did. Fewer appointments were missed in patients with a preferent referral, and among patients referred by their general practitioner a higher percentage failed to keep their appointment compared with those referred by a specialist. In the multivariate analysis, length of time on the waiting list and the source of referral were the only two independent predictive factors for non-attendance. CONCLUSIONS: A longer time on the waiting list and referral by a general practitioner are factors associated with patients failing to keep their endoscopy appointment.