Category Archives: Gastroenterology

Weak Link in Celiac Screening Guidelines

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A recent study (AS Faye et al. Clin Gastroenterol Hepatol 2019; 17: 463-8) finds a weak link in the screening guidelines for celiac disease. Generally, guidelines recommend screening all symptomatic first degree relatives and consider screening of asymptomatic first-degree relatives.  Yet, little is known about adherence to these guidelines.

The authors utilized emergency contact information from the electronic records of 2081 patients with biospy-diagnosed celiac disease to assess how commonly celiac disease testing occurs in patients who are first-degree relatives.

Key findings:

  • Of the 539 relatives identified, 212 (39.3%) were tested for celiac disease including 193 of 383 (50.4%) of first-degree relatives and 118 of 165 (71.5%) of symptomatic first-degree relatives.
  • Of the 383 first-degree relatives, only 116 (30.3%) had a documented family history of celiac disease.

Thus, this study shows that ~30% of symptomatic first degree relatives have not received celiac testing and that ~70% of all first-degree relatives do not have a documented family history.

My take: If a family history of celiac disease is not conveyed to health care providers, this greatly reduces the likelihood that symptomatic first degree relatives will undergo recommended screening. This weakness in screening could be overcome by either:

  1. changing to a policy which encourages screening all first degree relatives, whether symptomatic or asymptomatic
  2. leveraging technology (when feasible) to assure that family history is documented in all at risk patients

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Shenandoah National Park

 

New Serology for Celiac Disease?

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A recent study (RS Choung et al. Gastroenterol 156: 582-91) showed that synthetic neoepitopes of the transglutaminase-deamidated gliadin complex are better noninvasive biomarkers for detecting celiac disease and for monitoring mucosal healing.

Link to Graphical Abstract and Abstract: Synthetic Neoepitopes of the Transglutaminase–Deamidated Gliadin Complex as Biomarkers for Diagnosing and Monitoring Celiac Disease

The authors studied the serum samples from 90 patients with Celiac disease (CD) and from 79 healthy controls and developed a fluorescent peptide microarray platform  Then, the authors validated their findings in 82 patients with newly diagnosed CD and 217 controls.

Key findings:

  • 7% of patients with treated (with gluten free diet [GFD]) and healed CD had positive TTG-IgA and 27% of patients treated but unhealed CD mucosa had positive TTG IgA
  • With the synthetic neoepitopes, CD was identified with 99% sensitivity and 100% specificity.  The assay identified patients with CD with healed mucosa with an 84% sensitivity and 95% specificity.

My take: More precise noninvasive markers like these should help identify individuals with celiac disease and those who have responded (or not) to the recommended gluten free diet.

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Unrelated but important —NPR reports on another large study showing that MMR does not cause autism -Link: A Large Study Provides More Evidence That MMR Vaccines Don’t Cause Autism 

Related blog post: “Too many vaccines and autism” debunked

Link to full text of study from Annals of Internal Medicine: Measles, Mumps, Rubella Vaccination and Autism: A Nationwide Cohort Study

What Happens When Topical Steroids Are Stopped in Eosinophilic Esophagitis

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A recent retrospective study (T Greuter et al. Clin Gastroenterol Hepatol 2019; 17: 419-28) shows that patients with eosinophilic esophagitis who continued to take swallowed topical corticosteroids (STC) did much better than patients who did not.

Using the Swiss EoE database, the authors analyzed 229 patients with a mean age of 39 years at diagnosis.  Median followup was 5 years.  The authors initiated STC, almost all received fluticasone, at 1 mg BID for 2-4 weeks followed by maintenance treatment indefinitely.

Key findings:

  • There was frequent discontinuation of STC by patients, such that patients were actually taking STC at only 41% of visits.
  • Higher proportions of patients taking STCs were doing well compared to those not taking STCs:
    • clinical remission was 31% compared to 4.5% respectively (P<.001),
    • endoscopic remission was 49% compared to 18% respectively (P<.001)
    • histologic remission was 45% vs 10% respectively (P<.001)
    • complete remission was 16% vs 1% respectively (P<.001)
  • No dysplasia or mucosal atrophy was detected.  Esophageal candidiasis was observed in 2.7% of visits in patients taking STC

My take: This study shows that patients who maintained STC therapy had better esophageal outcomes than patients who stopped their treatment.  What is not known is the optimal long-term dose.

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Pictures from “Old Rag” Hike, Shenandoah National Park

Promising Biologic for Eosinophilic Esophagitis

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A recent study (I Hirano et al. Gastroenterol 2019; 156: 592-603) showed that RPC4046, a monoclonal antibody against IL13 is a promising agent for eosinophilic esophagitis. This multicenter double-blind study with 99 adults compared RPC4046 at doses of either 180 mg or 360 mg to placebo for 16 weeks.  Endoscopy was performed at baseline and at 16 weeks.  The study population included a high number who were considered steroid-refractory and excluded patients who were responsive to proton pump inhibitors. The study drug was administered initially as an IV load followed by weekly subcutaneous injections.

Key findings:

  • Mean changes in esophageal eosinophil count dropped by 94.8 in patients receiving 180 mg dosing and 99.9 in patients receiving 360 mg dosing.  In contrast, placebo-treated patients had a meager reduction of 4.4.
  • In this phase II study, there were no serious safety issues identified
  • There were no significant changes relative to placebo in dysphagia symptoms using the DSD (dysphagia symptom diary) composite score. Though there was improvement in global PRO measures compared to placebo.

There is an associated editorial (pg 545) explains the need for better therapies.  While both dietary therapies and topical steroids are likely effective in >70%, dietary therapy is plagued by problems with long-term adherence and there may become less effective with longer-term administration.

My take: Particularly for patients with refractory EoE, newer therapies are needed.  Given the chronic nature of EoE, cost of new treatments could be another hurdle.

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Screenshots: Peutz-Jeghers Syndrome, Alcohol #1 for Liver Transplantation, Case report Fanconi Syndrome due to Tenofovir Alafenamide

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These images (S Sengupta, S Bose. NEJM 2019; 380: 472) show hyperpigmented macules on the lips, oral mucosa and nose in the first frame, a target sign on CT scan indicative of intussception, and a jejunal resection with polyps that triggered the intussception. Related blog post: Update for Peutz-Jegher Syndrome

Relooking at Medications for Constipation-Predominant Irritable Bowel Syndrome

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A recent study (CJ Black et al. Gastroenterol 2018; 155: 1753-63) examined the effectiveness of secretagogues for constipation-predominant irritable bowel syndrome (IBS-C).  The authors conducted a systematic review and network meta-analysis with 15 eligible randomized controlled trials (8462 patients).

Key findings:

  • Linaclotide (290 mcg per day) was ranked first in efficacy using the end point recommended by the FDA for IBS-C trials
  • Tenapanor (50 mg twice a day) was ranked first for bloating
  • Plecanatide (6 mg per day) ranked first for safety
  • Diarrhea was significantly more common with all of the secretagogues except for lubiprostone; nausea was significantly more common with lubiprostone

The authors acknowledge the limitations in comparing medicines without direct head-to-head trials (which may never occur).  They state that linaclotide being superior to other treatments had a probability of 88%.

My take: This study indicates that linaclotide may be more likely to be effective than other IBS-C medications; all of these secretagogues have been shown to be superior to placebo.

In this same issue, pgs 1666-9 (J Ruddy), a patient describes her long journey with abdominal pain/GI symptoms.  She describes her initial experiences with physicians who were dismissive and not attentive. Ultimately, a physician listened to her and  helped her improve after explaining that she had a postinfectious IBS and provided treatment.

Related study: S Ishague et al. BMC Gastroenterol 2018; 18:71.  This randomized controlled trial which compared a multistrain probiotic (Bio-Kult, n=181) to placebo (n=179).  The probiotic group had a 69% decrease in abdominal pain compared to a 47% decrease in placebo group.

Sunrise, Death Valley

Five Ways to Lower the Risk of Colon Cancer

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A recent study (PR Carr, et al. Gastroenterol 2018; 155: 1805-15) used an ongoing population-based case-control DACHS study (in Germany since 2003) to determine the effects of lifestyle factors on the risk of colorectal cancer (CRC).

Among 4092 patients with CRC and 3032 control patients without CRC, the investigators examined five factors:

  • Smoking – For smoking, one point was given for being a nonsmoker or a former smoker with <30 pack years.
  • Alcohol consumption –  For alcohol, a point was garnered if consumption was moderate according to AICR recommendations.
  • Diet –  Diet quality was assessed based on WCRF/AICR recommendations (supplement table 1 [https://doi.org/10.1053/j.gastro.2018.08.044]). 1 point was given with highest diet scores.
  • Physical activity – A point was given with favorable physical activity which was based on moderate-intensity aerobic exercise for at least 150 minutes per week or 75 minutes of vigorous activity.
  • Body fatness – Those with a BMI between 18.5 and 25 which was considered a healthy weight were awarded a point.

 Key findings:

Compared to patients with 0 or 1 healthy lifestyle factor:

  • Participants with 2 points had odds ratio of 0.85
  • Participants with 3 points had odds ratio of 0.62
  • Participants with 4 points had odds ratio of 0.53
  • Participants with 5 points had odds ratio of 0.33

My take (borrowed from authors): Overall, 45% of CRC cases could be attributed to these lifestyle factors.  This occurred despite the patient’s genetic profile

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Vedolizumab -Could it Work for Eosinophilic Gastroenteritis?

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A recent study with only five patients (HP Kim et al. Clin Gastroenterol Hepatol 2018; 16: 1992-4) examined the use of vedolizumab for eosinophilic gastroenteritis.. The rationale was that α4β7 integrin may play an important role in eosinophilic localization in IBD and that blocking α4β7 may inhibit eosinophil recruitment to intestinal mucosa.  In addition, there are few proven therapies for EGE beyond steroids and dietary treatments.  The five patients in this study had been tried on numerous prior treatments and had a disease course of 6-17 years prior to vedolizumab.

Key findings:

  • Two of the five patients were able to wean/discontinue steroids, reported symptom improvement and had normal gastric and small bowel biopsies.  The median time to histologic followup was 2.2 months.
  • A third patient reported symptom improvement but declined a followup biopsy.

My take: A larger study of vedolizumab is needed for EGE.

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Calgary

Vonoprazan versus Lansoprazole for Initial Heartburn Relief

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A recent study (T Oshima et al. Aliment Pharmacol Ther 2019; 49: 140-6) showed that a new potassium-competitive acid blocker (P-CAB) can more rapidly improve symptoms than lansoprazole. Thanks to Ben Gold for this reference.

This small study with 32 adult patients with endoscopically-confirmed erosive esophagitis with frequent heartburn were randomized in a double-blind study and received either lansoprazole 30 mg or vonoprazan 20 mg before breakfast.  The authors note that with PPIs, there is a slow onset of action, such that ‘half of all patients remain symptomatic even after 3 days of treatment.” In contrast, vonoprazan can increase intragastric pH to almost 7 within 4 hours.

Key finding:

  • Heartburn relief occurred quicker with vonoprazan.  Complete relief was noted in 31.3% at day 1 compared with only 12.5% in the lansoprazole group.

My take: Vonoprazan is currently approved in Japan.

Related article: Update on the Use of Vonoprazan DY Graham, MP Dore; Gastroenterol 2018; Volume 154, Issue 3, Pages 462–466

Mesquite Flat Sand Dunes, Death Valley

Vedolizumab Drug Levels –Are They Needed?

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A recent retrospective study (E Dreesen et al Clin Gastroenterol Hepatol 2018; 16: 1937-46) with 179 consecutive patients (66 with ulcerative colitis, and 113 with Crohn’s disease) found that vedolizumab (VDZ) trough concentrations were correlated with response.

Key findings:

  • VDZ trough >30 mcg/mL at week 2, >24 mcg/mL at week 6, and >14 mcg/mL during maintenance were associated with effectiveness endpoints including endoscopic healing, physician global assessment and biochemical response (based on CRP).
  • Median VDZ trough levels during induction were 27.7 mcg/mL at week 2, 27.4 mcg/mL at week 6. With standard dosing, the maintenance VDZ trough was 13.5 mcg/mL at week 14
  • Higher BMI and more severe disease, based on CRP, albumin, and/or hemoglobin, were associated with lower VDZ trough levels and lower probability of mucosal healing (P<.05).

Interestingly, in the discussion the authors note that VDZ troughs above  3 mcg/mL completely saturate α4β7 intergrin.  This physiologic phenomenon is hard to reconcile with data showing better response with higher VDZ levels.  The authors note that “at present, there are not enough data in our study to support the role for TDM to guide clinical decision-making on dose escalation for vedolizumab.”

My take: This study implies that VDZ levels may help predict response but are not necessarily helpful in determining whether dose escalation is warranted.

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Riverwalk, Chattanooga