Geno, Debra M.

Abstract Background Baseline impedance measured with ambulatory impedance pH monitoring ( MII ‐pH) and a mucosal impedance catheter detects gastroesophageal reflux disease ( GERD ). However, these tools are limited by cost or patient tolerance. We investigated whether baseline impedance measured during high‐resolution impedance manometry ( HRIM ) distinguishes GERD patients from controls. Methods Consecutive patients with clinical HRIM and MII ‐pH testing were identified. Gastroesophageal reflux disease was defined by esophageal pH <4 for ≥5% of both the supine and total study time, whereas controls had an esophageal pH <4 for ≤3% of the study performed off PPI . Baseline impedance was measured over 15 seconds during the landmark period of HRIM and over three 10 minute intervals during the overnight period of MII ‐pH. Key Results Among 29 GERD patients and 26 controls, GERD patients had a mean esophageal acid exposure time of 22.7% compared to 1.2% in controls ( P <.0001). Mean baseline impedance during HRIM was lower in GERD (1061 Ω) than controls (2814 Ω) ( P <.0001). Baseline mucosal impedance measured during HRIM and MII ‐pH correlated ( r =0.59, P <.0001). High‐resolution esophageal manometry baseline impedance had high diagnostic accuracy for GERD , with an area under the curve ( AUC ) of 0.931 on receiver operating characteristics ( ROC ) analysis. A HRIM baseline impedance threshold of 1582 Ω had a sensitivity of 86.2% and specificity of 88.5% for GERD , with a positive predictive value of 89.3% and negative predictive value of 85.2%. Conclusions & Inferences Baseline impedance measured during HRIM can reliably discriminate GERD patients with at least moderate esophageal acid exposure from controls. This diagnostic tool may represent an accurate, cost‐effective, and less invasive test for GERD .

Summary Background To date there have been no clear features that aid in differentiating patients with eosinophilic oesophagitis (EoE) from PPI ‐responsive oesophageal eosinophilia ( PPI ‐ REE ). However, barium swallow roentgenography is a more sensitive and specific measure to detect subtle fibrostenotic remodeling changes present in EoE. We aim to characterise any clinical, endoscopic, histiological or barium roentgenographic differences between EoE and PPI ‐ REE . Aim To characterise any clinical, endoscopic, histiological or barium roentgenographic differences between EoE and PPI ‐ REE . Methods We performed a retrospective cohort analysis on data collected from a tertiary referral centre population from 2010 to 2015. Data from 66 patients with EoE and 28 patients with PPI ‐ REE were analysed. Cases were adults who met consensus guidelines for EOE , and had a barium swallow study within 6 months of the index endoscopy. Clinical, endoscopic, histiological and barium swallow findings were collected. Results Patients with EoE reported similar characteristics as PPI ‐ REE patients, except EoE patients were younger (35.6 vs. 46.6 years; P = 0.011), had earlier symptom onset (29.0 vs. 38.0 years; P = 0.026), and smaller oesophageal diameters on barium swallow (19.5 mm vs. 20; P = 0.042). Patients with EoE were more likely to have distal strictures (EoE 77% vs. 25%; P = 0.02) and, importantly, a greater likelihood of small calibre oesophagus (51.5% vs. 17.9%; P = 0.002). Moreover, EoE patients had a higher probability of developing small calibre oesophagus after 20 years of symptoms (72.3% vs. 30.2%; P = 0.074) compared to PPI ‐ REE patients. Conclusions When compared with eosinophilic oesophagitis, PPI ‐ REE patients demonstrate findings that suggest PPI‐responsive oesophageal eosinophilia to be a later onset, less aggressive form of oesophageal stricturing disease than eosinophilic oesophagitis.

Background Eosinophilic oesophagitis (EoE) is presumed to be an isolated oesophageal disease; yet other allergic diseases associated with eosinophilic infiltration of target tissues, such as asthma and eczema, show perturbed functions of other sites that may be involved in the diathesis of allergy modulation. Aim To analyse small intestinal permeability in patients with active EoE and in a separate group of patients in remission. Methods Small bowel permeability was determined using a dual sugar method by calculating lactulose:mannitol (L:M) ratio in 17 patients who met consensus criteria for active EoE (>15 eos/HPF) and 8 patients in remission (<5 eos/HPF). Data from 28 healthy controls was used for comparison. Results Patients with active EoE had significantly higher L:M ratios when compared to controls (0.045 vs. 0.033, p<0.001) and to EoE in remission (0.041 vs. 0.027, p<.001). There was no significant difference in L:M between the group with EoEin remission and healthy controls. The current data show that L:M ratio of 0.033 also provides a reasonable cut-off that defined the active EoE group compared to patients in remission. The main component explaining the change in L:M ratio was increased absorption (and excretion) of lactulose ((1601±106 ug) when compared to the EoE remission (969±91 ug) and control (1043±92 ug, p<.001) groups. Conclusions Small bowel permeability is overall increased in patients with active EoE, and is normal in patients with EoE in remission when compared to healthy controls. The role of the small bowel in active EoE deserves further investigation.