Author Archives: gutsandgrowth

About gutsandgrowth

I am a pediatric gastroenterologist at GI Care for Kids (previously called CCDHC) in Atlanta, Georgia. The goal of my blog is to share some of my reading in my field more broadly. In addition, I wanted to provide my voice to a wide range of topics that often have inaccurate or incomplete information. Before starting this blog in 2011, I would tear out articles from journals and/or keep notes in a palm pilot. This blog helps provide an updated source of information that is easy to access and search, along with links to useful multimedia sources. I was born and raised in Chattanooga. After graduating from the University of Virginia, I attended Baylor College of Medicine. I completed residency and fellowship training at the University of Cincinnati at the Children’s Hospital Medical Center. I received funding from the National Institutes of Health for molecular biology research of the gastrointestinal tract. I have authored numerous publications/presentations including original research, case reports, review articles, and textbook chapters on various pediatric gastrointestinal problems. Currently, I am the chair of the section of nutrition for the Georgia Chapter of the American Academy of Pediatrics. In addition, I am an adjunct Associate Clinical Professor of Pediatrics at Emory University School of Medicine. Other society memberships have included the American Academy of Pediatrics, the Food Allergy Network, the American Gastroenterology Association, the American Association for the Study of Liver Diseases, and the Crohn’s and Colitis Foundation. As part of a national pediatric GI organization called NASPGHAN (and its affiliated website GIKids) I have helped develop educational materials on a wide-range of gastrointestinal and liver diseases which are used across the country. Also, I have been an invited speaker for national campaigns to improve the evaluation and treatment of gastroesophageal reflux disease, celiac disease, eosinophilic esophagitis, and inflammatory bowel disease (IBD). Some information on these topics has been posted at my work website, www.gicareforkids.com, which has links to multiple other useful resources. I am fortunate to work at GI Care For Kids. Our group has 15 physicians with a wide range of subspecialization, including liver diseases, feeding disorders, eosinophilic diseases, inflammatory bowel disease, cystic fibrosis, DiGeorge/22q, celiac disease, and motility disorders. Many of our physicians are recognized nationally for their achievements. For many families, more practical matters include the following: – 14 office/satellite locations – physicians who speak Spanish – cutting edge research – on-site nutritionists – on-site psychology support for abdominal pain and feeding disorders – participation in ImproveCareNow – office endoscopy suite (lower costs and easier scheduling) – office infusion center (lower costs and easier for families) – easy access to nursing advice (each physician has at least one nurse) I am married and have two sons. I like to read, walk/hike, exercise, swim, and play tennis with my free time as well as go to baseball games. I do not have any financial relationships with pharmaceutical companies or other financial relationships to disclose. I have participated in industry-sponsored research studies.

Why Fewer Children Have Immune-Tolerant Hepatitis B Infection Than Previously

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A recent study (KB Schwarz et al. JPGN 2019; 69: 588-94) highlights the chronic hepatitis B virus (HBV) phenotypes from a large pediatric North American cohort (n=371).

  • Immune-tolerant HBV was define by HBe-Ag-positivity along with normal ALT levels.
  • Inactive carrier were HBe-Ag-negative with low HBV DNA/normal ALT.
  • Chronic hepatitis B (HBeAg positive and HBeAg negative) had high HBV DNA and abnormal ALT values.
  • Indeterminant HBV had characteristics did not allow them to classified in these four categories.

Key findings:

  • If local laboratory normative values were used 36% of children would have been classified as immune-tolerant*.  However, this drops down to 12% if updated upper limits of normal (ULN) are used based on Figure 3.
  • Using updated ULN, 62% had immune active HBeAg+ disease, 12% with immune-tolerant HBV, 4% with immune-active HBeAg-negative disease, 6% with inactive carrier, and 16% indeterminant HBV.

*There are a few discrepancies between Figure 3 and the abstract data.  The abstract states that 82% would be considered to have chronic hepatitis B (this is 62% in figure 3). The abstract states that 35% were immune-tolerant based on local lab values.

The data presented were cross-sectional data at time of patient enrollment.

My take: this study shows that very few children in this cohort were immune tolerant based on more precise ULN values.  The authors note that the cohort who were immune tolerant were largely drawn from Asian children (most often infected perinatally).

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Lincoln Park, Chicago

 

Surprising Genetic Mutations in Polyposis Study

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A recent cross-sectional study (PP Stanich et al. Clin Gastroenterol Hepatol 2019; 17: 2008-15, editorial 1942-44) identified a high frequency of genetic mutations among adults with at least 10 colonic polyps (cumulative burden of either adenomatous or hamartomatous).

This study had 3789 subjects who underwent multigene panel testing (MGPT) from 2012-16.

  • All subjects had at least 14 CRC-associated genes tested: APC, BMPR1A, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, PMS2, PTEN, SMAD4, STK11, TP53
  • A subset had 3 more newly recognized polyposis genes: GREM1, POLD1, and POLE

Key findings:

  • A mutation in at least 1 gene was found in 13.7%
  • In those with fewer than 20 cumulative adenomas, 7.6% had a disease-associated genetic mutation with the majority (5.3%) being nonpolyposis CRC genes
  • Younger patients, 18-29, were more likely to have mutations in any gene.  For example, among patients with 10-19 polyps, these younger patients had a mutation in one of these genes in 27.8%; this is more than double the rate in any other age group.
  • Hamartomatous polyps, regardless of number, had a very high yield with genetic testing: 40% with 10-19 polyps and 72% with 20-99 polyps.

Limitations:

  • There is a referral bias in that the population was derived from a testing laboratory (Ambry)
  • In clinical practice, genetic testing frequently results in variants of unknown significance

My take: This study shows that genetic mutations are fairly frequent in patients with cumulative polyp burden of 10 or more, especially in younger age groups.  The surprising finding is the high frequency of nonpolyposis CRC genes.  Thus, in patients with adenomatous polyposis, testing beyond APC and MUTYH may be needed.

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Atlanta Botanical Garden

Discrimination, Abuse, and Harassment in Medical Training

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A recent study (Y-Y Hu et al. NEJM 2019; 381: 1741-52) reported high rates of discrimination, abuse, and harassment based on a cross-sectional survey of general surgical residents (n=7409) in 2018.

Key findings:

  • 31.9% reported gender discrimination and 16.6% reported racial discrimination–with main source being patients/families
  • 30.3% reported verbal or physical abuse and 10.3% reported sexual harassment -with attending surgeons being the most frequent sources
  • Residents who experienced discrimination, abuse or harassment were more likely to have symptoms of burnout (OR 2.94) and suicidal thoughts (OR 3.07).  Overall, weekly burnout symptoms were noted in 38.5% of residents and 4.5% reported suicidal thoughts in previous year

The authors note that there were substantial numbers of programs with very low rates of mistreatment which indicates that improvement in training environment is feasible.

My take: This is a black eye for the entire healthcare field.  It is important to address these pervasive problems and to determine the rate of these issues in other areas of medicine.

Botanical Gardens, Chicago

Using Less Steroids for Autoimmune Hepatitis

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A recent retrospective study (S Pape et al. Clin Gastroenterol Hepatol 2019; 17: 2068-75) with 451 adults (1978-2017) examined outcomes among patients based on steroid dosing.

A high-dose group (n=281) with initial prednisone/prednisolone dose of ≥0.5 mg/kg/day was compared with a low dose group (n=170) <0.5 mg/kg/day.  The low dose group had higher rates of cirrhosis (25.9% vs. 15.3%) but lower median ALT values (7.1 ULN vs. 13.4 ULN) and lower median bilirubin values (48 vs 29 micromol/L).

Key findings:

  • There was no difference in rates of transaminase normalization at 1 year: 76.2% vs 77.6%
  • Transaminase normalization was lower in patients with cirrhosis 58.1% compared to 70.7% with cirrhosis
  • Most patients were receiving low-dose steroids at 6 months, 87.4% in high-dose group compared to 83.5% in low-dose group
  • Cumulative steroid dose was lower in low-dose group, with median of 2573 mg over 6 months compared to 3780 mg

Though, not studied in this report, AASLD has recommended use of immunoglobulin levels may help with immunosuppression titration. The editorial (pg 1948-49) notes that budesonide is another alternative for AIH without cirrhosis, though “long-term outcomes including histologic remission and appropriate tapering strategy for budesonide are currently lacking.”

My take: Particularly in patients without severe inflammation, lower steroid doses can be considered for autoimmune hepatitis.

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Atlanta Botanical Garden

China Is Catching and Passing U.S. with NAFLD Plus Updates

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F Zhou et al. Hepatology 2019; 70: 1119-33. The authors performed a systematic review (n=392 studies, more than 2 million subjects) and found that NAFLD in China increased from 25.4% in 2008-2010 to 32.3% in 2015-2018. The pooled prevalence across all studies was 29.2%. The associated editorial speculates that some of this increase is related to diet changes as well as PNPLA3 gene.  This allele “is more common among East Asians than Caucasians”  It is lower in African Americans in the U.S. which helps explain why this population is at reduced risk.

JB Schwimmer, JS Johnson et al Gastroenterol 2019; 157: 1109-22.  In this prospective study with 87 children (89% Hispanic), the authors associated fecal microbiomes with NAFLD and NASH.  Both NAFLD and NASH were associated with intestinal dysbiosis with lower diversity and high abundance of Prevotella copri. Full text link: Microbiome Signatures Associated With Steatohepatitis and Moderate to Severe Fibrosis in Children With Nonalcoholic Fatty Liver Disease

S Pelusi et al. Clin Gastroenterol Hepatol 2019; 17: 2310-9.  This study analyzed data from 1738 subjects (45% with severe obesity) who had undergone liver biopsy.  132 of 389 (33.9%) with significant fibrosis did NOT have nonalcoholic steatohepatitis (NASH) and 39 patients (10%) had no inflammation. NASH diagnosis required steatosis (≥5% of hepatocytes), hepatocellular ballooning, and lobular inflammation. Factors associated with significant fibrosis in the absence of NASH, included fasting hyperglycemia, severe steatosis, mild inflammation or ballooning, and PNPLA3 1148M variant.  My take: this study shows that the finding of NASH on liver biopsy is NOT required for the development of severe liver disease related to NAFLD.

D Linden et al. Molecular Metabolism 2019; 22: 49-61. This study, summarized in Gastroenterol 2019; 157: 1156-9) showed that PNPLA3 silencing with antisense oligonucleotides ameliorates NASH in PNPLA3 1148M knock-in mice.  The summary notes that the mutated 1148 M PNPLA3 protein variant accumulates on lipid droplets altering clearance and affecting triglycerides and phospholipid turnover.

Genetic Risk for Failing Infliximab

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A recent study (A Wilson et al. AP&T 2019; https://doi.org/10.1111/apt.15563) noted that a HLADQA1*05A>G genotype predicts a high risk of developing anti-drug antibodies in patients receiving infliximab.

Here’s a link to the full article:  HLADQA1*05 genotype predicts anti‐drug antibody formation and loss of response during infliximab therapy for inflammatory bowel disease

Here’s the abstract (my highlights in bold):

Background

Anti‐drug antibodies (ADAs) are a leading contributor to infliximab loss of response and adverse drug events. It is not feasible to identify patients at risk of antibody formation before initiating infliximab. The genetic variation HLADQA1*05 (rs2097432) has been linked to infliximab antibody formation in Crohn’s disease (CD).

Aims

To evaluate the association between HLADQA1*05 and infliximab antibody formation, infliximab loss of response, treatment discontinuation and adverse drug events in patients with inflammatory bowel disease (IBD)

Methods

In a retrospective cohort study, infliximab‐exposed patients with IBD (n = 262) were screened for the genetic variation, HLADQA1*05A>G (rs2097432). Risk of infliximab ADA formation, infliximab loss of response, adverse events and discontinuation were assessed in wild‐type (GG) and variant‐carrying (AG or AA) individuals.

Results

Forty per cent of all participants were HLADQA1*05A>G variant carriers, with 79% of participants with infliximab antibodies carrying at least one variant allele. The risk of infliximab antibody formation was higher in HLADQA1*05A>G variant carriers (adjusted HR = 7.29, 95% confidence interval (CI) = 2.97‐17.191, P = 1.46 × 10−5) independent of age, sex, weight, dose and co‐immunosuppression with an immunomodulator. Variant carrier status was associated with an increased risk of infliximab loss of response (adjusted HR = 2.34, 95% CI = 1.41‐3.88, P = .001) and discontinuation (adjusted HR = 2.27, 95% CI = 1.46‐3.43, P = 2.53 × 10−4) although not with infliximab‐associated adverse drug events.

Conclusions

HLADQA1*05 is independently associated with a high risk of infliximab antibody formation in addition to infliximab loss of response and treatment discontinuation. There may be a role for genotype‐guided application of combination therapy in IBD.

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Need Liver, Will Travel (2019)

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A recent study (AJ Kwong et al Clin Gastroenterol Hepatol 2019; 17: 2347-55) quantifies the potential advantage of moving to receive a liver transplant. This had been discussed in 2016 blog post as well (Need Liver, Will Travel)

During the study period (2004-2016), there were 104,914 waitlist registrations.

Key findings:

  • 60.985 patients received a liver transplant during the study period
  • 2930  (2.8%) pursued listing at a distant center
  • Distant listing was associated with a 22% reductinon in the risk of death within 1 year

My take: this study highlights socioeconomic disparity in acquiring a liver transplant along with potential geographic disparities.

Related article:

“Transplantation Traffic –Geography as Destiny for Transplant Candidates” NEJM 2014; 271: 2450-52.  Describes ongoing geographic inequality in organ distribution and obstacles to improving allocation.

Related blog posts:

Botanical Garden,, Chicago