Drug-induced side effects affecting the gastrointestinal tract

With the ever-growing armamentarium of pharmacological agents, the gastrointestinal drug-induced side effects of dyspepsia, nausea, vomiting, diarrhoea and constipation are increasingly seen. They are often self-limiting and without serious sequelae, but of greater concern is drug-induced mucosal ulceration that can manifest as gastrointestinal haemorrhage, stricture and perforation. These complications are mainly attributable to NSAIDs and aspirin, which can injure the mucosa anywhere along the gastrointestinal tract. These iatrogenic serious side effects can be reduced with co-prescription of a proton pump inhibitor, substitution of a COX-2 inhibitor and eradication of Helicobacter pylori when the bacterium is present. Other recognised gastrointestinal complications include small intestinal diaphragm, microscopic colitis, a range of hepatotoxic effects and pancreatitis. The introduction of new classes of drugs has resulted in new adverse effects that require consideration in patients presenting with gastroenterological symptoms. These include pill oesophagitis from bisphosphonates and ischaemic colitis relating to serotonin antagonists. Here, the authors review the literature on drug-induced complications of the gastrointestinal tract and present the pertinent management issues relevant to clinical practice.

An unusual complication of gastric bypass: perforated duodenal ulcer

Peptic ulcer in the excluded segment of a gastric bypass has been reported in the literature in only 17 cases. We report a 54-year-old woman with a perforated duodenal ulcer, who had undergone laparoscopic Roux-en-Y gastric bypass surgery for morbid obesity 15 months previously. She was successfully treated by a laparoscopic repair of the perforated duodenal ulcer.

Evidence for the role of gastric mucosa at the secretion of soluble triggering receptor expressed on myeloid cells (strem-1) in peptic ulcer disease

AIM: To investigate the role of gastric mucosa at the secretion of sTREM-1 in peptic ulcer.

METHODS: Seventy two patients were enrolled; 35 with duodenal, 21 with gastric ulcer and 16 with chronic gastritis. Patients were endoscoped and gastric juice was aspirated. Patients with duodenal and gastric ulcer underwent a second endoscopy post-treatment. Biopsies were incubated in the absence/presence of endotoxins or gastric juice. Supernatants were collected and sTREM-1 and TNFα were measured by enzyme immunoabsorbent assays. Scoring of gastritis was performed before and after treatment according to updated Sydney score.

RESULTS: Patients with duodenal and gastric ulcer and those with chronic gastritis had similar scores of gastritis. sTREM-1 was higher in supernatants of tissue samples of H pylori-positive than of H pylori-negative patients with gastric ulcer. Median (± SE) sTREM-1 was found increased in supernatants of patients with gastric ulcer before treatment (203.21 ± 88.91 pg/1000 cells) compared to supernatants either from the same patients post-treatment (8.23 ± 5.79 pg/1000 cells) or from patients with chronic gastritis (6.21 ± 0.71 pg/1000 cells) (P < 0.001 and < 0.001, respectively). Similar differences for sTREM-1 were recorded among LPS-stimulated tissue samples of patients (P = 0.001). Similar differences were not found for TNFα. Positive correlations were found between sTREM-1 of supernatants from patients with both duodenal and gastric ulcer before treatment and the degree of infiltration of neutrophils and monocytes.

CONCLUSION: sTREM-1 secreted by the gastric mucosa is an independent mechanism connected to the pathogenesis of peptic ulcer. sTREM-1 was released at the presence of H pylori from the inflamed gastric mucosa in the field of gastric ulcer.

Association between genetic polymorphisms in the cyclooxygenase-1 gene promoter and peptic ulcers in Japan

Cyclooxygenase-1 (COX-1) has been regarded as a constitutively expressed enzyme that generates prostaglandins for gastrointestinal integrity. We attempted to clarify the association between potentially functional polymorphisms (T-1676C and A-842G/C50T) in the COX-1 gene promoter and gastroduodenal disorders in a Japanese population. The study was performed with 480 stocked DNAs from subjects (gastric ulcers in 93 subjects and duodenal ulcers in 44) with no evidence of gastric malignancy. We employed the PCR-SSCP method to detect gene polymorphisms. The severity of histological chronic gastritis in antral biopsy specimens was classified according to the updated Sydney system. The T-1676C polymorphism was not associated with either gastric mucosal atrophy or infiltration of inflammatory cells into gastric mucosa. In non-NSAID (non-steroidal anti-inflammatory drug) users, male gender and Helicobacter pylori (HP) infection were significantly associated with both gastric and duodenal ulcers, whereas the -1676T allele carrier was significantly associated with only gastric ulcers (OR, 2.86; 95% CI, 1.29-6.34). In NSAID users, the number of -1676T alleles was significantly associated with developing gastroduodenal ulcers (OR, 5.80; 95% CI, 1.59-21.1), whereas male gender and HP infection were not. The -842T/ C50T polymorphism was not detected in any of the 480 Japanese subjects. In conclusion, a carrier of the -1676T allele in the COX-1 gene promoter, as well as HP infection and male gender, seem to be significant risk factors for developing gastric ulcers, and the number of -1676T alleles was also a significant risk factor for the NSAID-induced ulcer, whereas the frequency of the A-842G polymorphism was thought to be very rare in the Japanese population.

Laparoscopic management of duodenal ulcer perforation: is it advantageous?

BACKGROUND

Surgery is the mainstay of treatment of patients with peptic duodenal perforation. With the advent of minimal access techniques, laparoscopy is being used for the treatment of this condition.

METHODS

Retrospective analysis of 120 consecutive patients (mean age 44.5 years; 111 men) with duodenal ulcer perforation who had undergone laparoscopic surgery.

RESULTS

87 patients had history of tobacco consumption, 12 were chronic NSAID users, 72 had Helicobacter pylori infection and 36 had a co-morbid condition. The mean time to surgery from onset of symptoms was 28.4 hours. The median operating time was 46 minutes. All patients underwent laparoscopic closure of the perforation with Graham's patch omentopexy; 12 patients underwent additional definitive ulcer surgery. The morbidity rate was 7.5%; no patient needed conversion to open surgery or died. The mean postoperative hospital stay was 5.8 days.

CONCLUSION

Results of laparoscopic management of perforated peptic ulcer are encouraging, with no conversion to open surgery, low morbidity and no mortality.

New Molecular Mechanisms of Duodenal Ulceration

Stress is a major etiologic factor in the pathogenesis of gastric and duodenal ulceration, as first described in rats by Hans Selye. In patients with "peptic ulcers" duodenal ulcers are more frequent than gastric ulcers (except in Japan). Thus, our research during the last three decades focused on the molecular mechanisms of duodenal ulcer in rodent models of chemically induced duodenal ulceration, and here we review our three recent findings: Endothelins (ET-1), the immediate early gene egr-1 and imbalance of angiogenic/antiangiogenic molecules. Namely, we found an enhanced expression and release of ET-1 within 15-30 min after the administration of duodenal ulcerogen cysteamine, resulting in local ischemia that triggers the expression of hypoxia-inducible factors (HIF-1alpha). Our gene expression studies also revealed an early (0.5-2 h) increase in the expression of egr-1 that is followed (12-24 h) by upregulation of angiogenic growth factors (e.g., VEGF, bFGF, PDGF). Surprisingly, this event is also associated with an enhanced production of angiostatin and endostatin that probably counteract the beneficial effect of angiogenic molecules. Thus, the initial injury to endothelial and epithelial cells in duodenal ulceration seems to be aggravated (and not initiated) by HCl and proteolytic enzymes. The resulting mucosal necrosis does not rapidly heal because of the imbalance of VEGF and angiostatin/endostatin, hence duodenal ulcers develop. The experimental ulcers Selye described morphologically are now characterized at the molecular and genome level, involving unexpected mediators like ET-1, egr-1 and angiogenesis-related molecules.

Helicobacter pylori: review of research findings

Helicobacter pylori attracted widespread interest from gastroenterologists because of its potential aetiologic role in disorders of the upper gastrointestinal tract. Based on extensive microbiological studies, Campylobacter pylori was renamed Helicobacter pylori, and the organism represents a new genus of bacteria. It is generally accepted that H. pylori causes chronic, non-specific gastritis (type B gastritis). The inflammatory response occurs even though the bacterium does not penetrate the gastric epithelium; it is found on the surface of and adjacent to the epithelium. The clinical significance of histological gastritis is unknown. The bacterium is often found in asymptomatic subjects. In Caucasian adults, the prevalence of infection increases with increasing age. Higher rates of infection are found in blacks and Hispanics than would be expected for their age. Whether these different rates are the result of racial or socioeconomic factors is not known. It is theorized, but not proven, that high rates of infection with H. pylori at an early age may explain the high incidence of gastric carcinoma found in Hispanic populations. H. pylori is found in almost every patient with duodenal ulcer disease, although no direct evidence for a causal relationship exists. Indirect evidence is based on the findings that if H. pylori infection is eradicated, ulcer recurrence is less likely (up to one year of follow-up). A small percentage of patients have a relapse despite eradication of the organism, suggesting a role for other factors in duodenal ulcer disease. The role of H. pylori in gastric ulcer disease is unknown. Seventy to eighty per cent of patients with gastric ulcer have evidence of H. pylori infection, and preliminary data seem to support the existence of two distinct aetiologic groups: those with gastric ulcers related to H. pylori infection and those with gastric ulcers related to use of non-steroidal anti-inflammatory drugs. The role of H. pylori in non-ulcer dyspepsia is unknown. Some clinicians believe that H. pylori causes non-ulcer dyspepsia and treat these patients for H. pylori infection. However, the data supporting this practice are poor. Treatment is only recommended for patients with resistant duodenal ulcers and patients who have frequent relapses of duodenal ulcers and who are willing to take triple-drug therapy (bismuth compounds, metronidazole, tetracycline) for the infection. As 95% of patients with duodenal ulcer have evidence of H. pylori infection, there is probably little need to confirm the diagnosis of H. pylori infection.

Bilateral ureteral stenosis and duodenal perforation in a patient with dermatomyositis

We report the case of a 19-year-old man with dermatomyositis who developed abdominal pain and anuria. The examination revealed bilateral ureteral stenosis. The patient also developed multiple ulcerations of the duodenum with perforations. The clinical feature was considered to represent that of juvenile dermatomyositis, which is characterized by systemic necrotizing vasculitis. Rheumatologists should be alerted about this serious complication in patients with childhood or young adult dermatomyositis presenting with abdominal complaints.

Association between interleukin-1 gene polymorphisms and Helicobacter pylori infection in gastric carcinogenesis in a Chinese population

BACKGROUND AND AIM

Helicobacter pylori is a major cause of chronic gastritis and peptic ulcer disease and a definite carcinogen for gastric adenocarcinoma. However, the underlying pathogenic mechanisms are not fully understood. Interleukin-1 (IL-1) is a key cytokine involved in H. pylori-induced gastric inflammation. The present study aimed to determine polymorphisms of IL-1B and IL-1 receptor antagonist (IL-1RN) genes and their association with H. pylori infection and gastroduodenal diseases in Chinese patients.

METHODS

Three hundred and ninety-nine patients with gastroduodenal diseases (129 chronic gastritis, 127 duodenal ulcer and 143 non-cardiac gastric cancer) and 264 healthy controls were genotyped for IL-1B-511 and IL-1RN gene polymorphisms by the PCR-RFLP method. H. pylori infection status was determined by a validated serological test.

RESULTS

The frequency of IL-1B-511 T allele was significantly higher in H. pylori positive patients with non-cardiac gastric cancer than in both H. pylori negative patients with non-cardiac gastric cancer (60%vs 46%, P = 0.0342, OR = 1.666, 95% confidence interval [CI]: 1.045-2.656) and in healthy controls (60%vs 48%, P = 0.0071, OR = 1.665, 95%CI: 1.149-2.412). However, the polymorphism was not associated with chronic gastritis and duodenal ulcer. Multivariate logistic regression analyses identified that IL-1B-511 T/T carrier status was an independent risk factor for non-cardiac gastric cancer in the presence of H. pylori infection (adjusted OR = 3.01, 95%CI: 1.27-7.11, P = 0.01), and the frequency of IL-1B-511 T allele was an increased risk factor for developing gastric cancer (P = 0.03, adjusted OR = 2.29, 95%CI: 1.08-4.86). There was no association between IL-1RN gene polymorphisms and H. pylori infection and other gastroduodenal diseases.

CONCLUSION

IL-1B-511 T allele is associated with H. pylori infection in non-cardiac gastric cancer in a Chinese population. The IL-1B-511 gene polymorphism appears to play an important role in gastric carcinogenesis in Chinese patients with H. pylori infection.

The papilla of Vater just below the pylorus presenting as recurrent duodenal ulcer bleeding

The papilla of Vater emptying into the duodenal bulb site is extremely rare and considered an aberrant condition. We report here a case with recurrent duodenal ulcer bleeding associated with this anomaly. A 42-year-old man was admitted to St. Mary Hospital because of tarry stool for three days. Despite no documented etiology to explain recurrent ulceration, the patient had about ten episodes of ulcer bleeding since 1995. On duodenoscopy, 1.0 x 0.6 cm sized active stage duodenal ulcer with oozing was observed at the posterior wall side below the pylorus. The papilla of Vater was bulging just below the pylorus. Bile juice was excreted from its opening. Pancreatic duct and common bile duct, which drained into the bulb site, were observed on ERCP. In this report, we show that recurrent duodenal ulcer can be associated with the papilla of Vater just below the pylorus.

Migrated biliary stent predisposing to fatal ERCP-related perforation of the duodenum

ERCP may be associated with very serious and even fatal complications. Internal drainage with endoscopical prostheses has been used as a palliative treatment for malignant bile duct obstruction. We report a rare case of subcutaneous emphysema with a fatal outcome. The emphysema resulted from a perforation of a duodenal ulcer during ERCP due to a migrated biliary stent that had been previously endoscopically placed.

Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA, babA2 genotypes and correlation with clinical outcome in Turkish patients with dyspepsia

BACKGROUND

Distinct virulence factors of Helicobacter pylori have been associated with clinical outcome of the infection; however, considerable variations have been reported from different geographic regions and data on genotypes of Turkish H. pylori isolates are sparse.

AIM

To determine the prevalence of specific genotypes of H. pylori in Turkish patients with dyspepsia.

MATERIALS AND METHODS

Ninety-three H. pylori-positive patients [30 with non-ulcer dyspepsia (NUD), 30 with duodenal ulcer (DU), and 33 with gastric cancer (GC)] who were admitted to our endoscopy unit due to dyspepsia were enrolled in the study. H. pylori infection was confirmed in all patients by histology and rapid urease test (RUT). The presence of vacA alleles, cagA, cagE, iceA, and babA2 genotypes were determined by polymerase chain reaction (PCR). Chi-squared test and Fisher's exact test were used for statistical comparisons and multivariate regression analysis was performed to find out independent predictors of different clinical outcomes.

RESULTS

Turkish strains examined predominantly possessed the vacA s1,m2 (48.4%) and s1,m1 (40.7%) genotypes. The vacA s1a genotype was detected in 66.7, 96.4, and 87.9% of isolates from patients with NUD, DU, and GC, respectively, and its presence was significantly associated with that of DU (p = .004), GC (p = .043), and cagA gene (p = .021). None of the cases was found to harbor the s1c genotype. The frequencies of the cagA and cagE genes among studied isolates were 73.6 and 59.3%, respectively. The cagA gene was significantly associated with the presence of DU (p = .004) and GC (p = .003), and the cagE gene, too, was significantly associated with the presence of DU (p = .002) and GC (p = .000). All H. pylori isolates possessed the iceA gene. In all, 68 isolates (74.7%) were positive for iceA1 and 23 (25.3%) for iceA2. The frequency of icea1 gene was significantly higher in cases with GC (85%) than in cases with NUD (60%) (p = .026). The frequency of babA2 gene was 23.3, 46.4, and 87.9% in isolates of patients with NUD, DU, and GC, respectively. When compared to cases with NUD (p = .000) and DU (p = .000), the presence of babA2 gene was significantly higher in cases with GC. Multivariate regression analysis disclosed cagE (p = .006) and vacA s1a (p = .027) genotypes to be independent predictors of DU and babA2 (p = .000) and cagE (p = .013) genotypes to be independent predictors of GC.

CONCLUSIONS

H. pylori vacA s1a, cagA, cagE genotypes have significant relations with the presence of DU and GC, and iceA1, babA2 with GC in Turkish patients with dyspepsia, whereas cagE and vacA s1a genotypes are independent predictors of DU, and babA2 and cagE genotypes are independent predictors of GC.

Helicobacter pylori infection with a duodenal ulcer in a 6-year-old boy

A 6-year-old boy was hospitalized because of dark feces and facial pallor of 1 weeks duration. Other gastrointestinal symptoms, including vomiting and abdominal pain, were absent, but he felt dizziness when standing and fatigue on effort. Hematologic studies revealed iron-deficiency anemia, and endoscopy showed gastric erosions and a duodenal ulcer. All test results for Helicobacter pylori infection, including H. pylori antigen in stool, anti-H. pylori IgG immunoassay in serum, and the (13)C-urea breath test, were positive. Because an H. pylori-associated gastric ulcer had been diagnosed with endoscopy in the patients father 3 years earlier, father-son transmission was suspected. The patient was treated with triple-agent eradication therapy (proton pump inhibitor [lansoprazol], amoxicillin, and clarithromycin) for 2 weeks. One month after therapy was completed, eradication of H. pylori was confirmed by negative results on the stool antigen test. Peptic ulcer disease can occur in young children, as in this case. The stool antigen test kit is a useful and reliable method that can be used even in preschool children to diagnose H. pylori infection.

[The course of Helicobacter pylori-associated duodenal ulcer concurrent with chronic opisthorchiasis]

The purpose of the investigation was to study the specific features and the course of Helicobacter pylori-associated duodenal ulcer (DU) concurrent with chronic opisthorchiasis (CO) A hundred and twenty-seven patients with H. pylori-associated DU were examined. Of them 78 patients were found to have H. pylori-associated DU concurrent with CO. In mixed pathology, asthenovegetative disorders were observed in most patients, one third had eosinophilia. With an over 10-year history of CO, acid production and pepsin secretion substantially decreased in both phases of gastric secretion. Mucosal atrophic changes were found mainly in the antral portion of the stomach, which frequency correlated with the duration of Opisthorchis invasion. The incidence of atrophic duodenitis tripled. All the patients received eradication therapy by the classical first-line treatment regimen including omeprazole and the antibiotics clarithromycin and amoxicillin. In the mixed pathology group, the time of ulcerative defect scarring increased by an average of 5 days. Fifty-eight with pathology continuously receiving the antisecretoty agent underwent dehelminthization with the anthelminthic bilthricide in 33 patients and with the plant anthelminthic dry aspen bark extract in 25. Evaluation of the efficiency of eradication therapy indicated that the best results of H. pylori eradication had been achieved in the patients dehelminthized with bilthricide. Assessment of long-term results showed that after multimodality therapy (eradication followed by bilthricide dehelminthization), there were no relapses for 2 years and there was a drop in the number of patients resorting to on-request therapy in patients with H. pylori-associated DU concurrent with CO.