Molecular detection of Helicobacter pylori antibiotic resistance in stool vs biopsy samples

AIM To compare(1) demographics in urea breath test(UBT) vs endoscopy patients; and(2) the molecular detection of antibiotic resistance in stool vs biopsy samples.METHODS Six hundred and sixteen adult patients undergoing endoscopy or a UBT were prospectively recruited to the study. The Geno Type Helico DR assay was used to detect Helicobacter pylori(H. pylori) and antibiotic resistance using biopsy and/or stool samples from CLOpositive endoscopy patients and stool samples from UBT-positive patients. RESULTS Infection rates were significantly higher in patients referred for a UBT than endoscopy(overall rates: 33% vs 19%; treatment-na?ve patients: 33% vs 14.7%, respectively). H. pylori-infected UBT patients were younger than H. pylori-infected endoscopy patients(41.4 vs 48.4 years, respectively, P < 0.005), with a higher percentage of H. pylori-infected males in the endoscopy-compared to the UBT-cohort(52.6% vs 33.3%, P = 0.03). The Geno Type Helico DR assay was more accurate at detecting H. pylori infection using biopsy samples than stool samples [98.2%(n = 54/55) vs 80.3%(n =53/66), P < 0.005]. Subset analysis using stool and biopsy samples from CLO-positive endoscopy patients revealed a higher detection rate ofresistance-associated mutations using stool samples compared to biopsies. The concordance rates between stool and biopsy samples for the detection of H. pylori DNA, clarithromycin and fluoroquinolone resistance were just 85%, 53% and 35%, respectively. CONCLUSION Differences between endoscopy and UBT patients provide a rationale for non-invasive detection of H. pylori antibiotic resistance. However, the Geno Type Helico DR assay is an unsuitable approach.

Small bowel Dieulafoy lesions: An uncommon cause of obscure bleeding in cirrhosis

Dieulafoy lesions(DLs) are an uncommon cause of gastrointestinal bleeding, accounting for up to 2% of cases overall. They are largely under recognised and difficult to treat. Up to 95% occur in the stomach, and only case reports document their occurrence in the small bowel(SB). Little is known about their pathophysiology, although there have been associations made previously with chronic liver disease, thought to be due to the erosive effects of alcohol on the mucosa overlying the abnormally dilated vessels. We present a case series of 4 patients with a long duration of obscure gastrointestinal bleeding, who were diagnosed with small intestinal DLs and incidentally diagnosed with chronic liver disease. The histories describe the challenges in both diagnosis and treatment of small intestinal DLs. Our case series suggest a previously unreported link between chronic liver disease and SB DLs which may be due to anatomical vasculature changes or a shift in angiogenic factors as a consequence of portal hypertension or liver cirrhosis.

Assessment of serum angiogenic factors as a diagnostic aid for small bowel angiodysplasia in patients with obscure gastrointestinal bleeding and anaemia

To assess the use of serum levels of angiopoietin-1 (Ang1), Ang2 and tumor necrosis factor-α (TNFα) as predictive factors for small bowel angiodysplasia (SBA). METHODSSerum samples were collected from patients undergoing capsule endoscopy for any cause of obscure gastrointestinal bleeding (OGIB) or anaemia. Based on small bowel findings patients were divided into 3 groups: (1) SBA; (2) other bleeding causes; and (3) normal, according to diagnosis. Using ELISA technique we measured serum levels of Ang1, Ang2 and TNFα and compared mean and median levels between the groups based on small bowel diagnosis. Using receiver operator curve analysis we determined whether any of the factors were predictive of SBA. RESULTSSerum samples were collected from a total of 120 patients undergoing capsule endoscopy for OGIB or anaemia: 40 with SBA, 40 with other causes of small bowel bleeding, and 40 with normal small bowel findings. Mean and median serum levels were measured and compared between groups; patients with SBA had significantly higher median serum levels of Ang2 (3759 pg/mL) compared to both other groups, with no significant differences in levels of Ang1 or TNFα based on diagnosis. There were no differences in Ang2 levels between the other bleeding causes (2261 pg/mL) and normal (2620 pg/mL) groups. Using Receiver Operator Curve analysis, an Ang2 level of > 2600 pg/mL was found to be predictive of SBA, with an area under the curve of 0.7. Neither Ang1 or TNFα were useful as predictive markers. CONCLUSIONElevations in serum Ang2 are specific for SBA and not driven by other causes of bleeding and anaemia. Further work will determine whether Ang2 is useful as a diagnostic or prognostic marker for SBA.

Pill Cam COLON 2~? as a pan-enteroscopic test in Crohn's disease

A recent paper by Boal Carvalho et al demonstrates the potential of Pill Cam COLON 2?(PCC2) as a panenteric investigation in Crohn's disease(CD). Our own prospective data in patients with known CD also shows good correlation between PCC2 and small/large bowel investigations(R = 0.896,P < 0.0004/R = 0.6667,P <0.035). Larger studies are warranted to prospectively validate the use of PCC2 in the investigation and monitoring of both small and large bowel CD.

Shared changes in angiogenic factors across gastrointestinal vascular conditions:A pilot study

BACKGROUND Neovascularisation is common to a variety of gastrointestinal(GI)disorders with differing aetiologies and presentations;usually affecting adults above 60 years.Shared angiogenic factors modulated by disease specific elements could be a common denominator and represent novel diagnostic and therapeutic targets.As yet,assessment of angiogenic factors across several GI vascular disorders associated with recurrent bleeding and anaemia has not been reported.AIM To assess serum levels of angiogenic factors in several intestinal vascular disorders.METHODS A case control study was performed in Tallaght University Hospital in patients with endoscopically proven small bowel angiodysplasia(SBA),portal hypertensive gastropathy(PHG),gastric antral vascular ectasia(GAVE)and nonbleeding,non-anaemic controls.Using enzyme-linked immunosorbent assay,concentrations of Angiopoietin 1(Ang-1),Ang-2 and vascular endothelial growth factor(VEGF)were measured from 2 serum tubes of blood following informed consent.The relative expression of Ang-1 and Ang-2 and Ang-1/2 ratio was calculated and compared between groups.Statistical analysis was applied using a t-test,and a P value of<0.05 was considered significant.RESULTS To date 44 samples were tested:10 SBA,11 PHG,8 GAVE and 15 controls.Mean age 60(range 20-85)years and 20(45%)were males.Controls were significantly younger(49 years vs 66 years,P=0.0005).There was no difference in VEGF levels between the groups(P=0.6).SBA,PHG and GAVE Ang-1 levels were similar and were significantly lower than controls,(P=0.0002,95%CI:241 to 701).Ang-2 levels were statistically higher in PHG and GAVE groups compared to controls(P= 0.01, 95%CI: 77.8 to 668) and as a result, also had a lower Ang-1/2 ratioscompared to controls. While SBA Ang-2 levels were higher than controls, this didnot reach statistical significance. Neither age nor haemoglobin level, which wassimilar between disease groups, could explain the difference. In addition, themedian Ang-1/Ang-2 ratio for all patients was found to be significantly lowercompared to controls, 8 vs 28 respectively, P = 0.001, 95%CI: -27.55 to -7.12.CONCLUSIONOur novel pilot study suggests common alterations in Ang-1 and Ang-2 levelsacross several GI vascular disorders. Differences in Ang-1/Ang-2 ratios amongvascular disorders compared to controls suggest disease-specific modulation.