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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. During my fellowship, I had the opportunity to work with some of the most amazing pediatric gastroenterologists and mentors. Some of these individuals included Mitchell Cohen, William Balistreri, James Heubi, Jorge Bezerra, Colin Rudolph, John Bucuvalas, and Michael Farrell. I am grateful for their teaching and their friendship. During my training with their help, I received a nationwide award for the best research by a GI fellow. I have authored numerous publications/presentations including original research, case reports, review articles, and textbook chapters on various pediatric gastrointestinal problems. In addition, I have been recognized by Atlanta Magazine as a "Top Doctor" in my field multiple times. Currently, I am the vice 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 North American Society for Pediatric Gastroenterology Hepatology and Nutrition (NASPGHAN), 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, hepatitis C, 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 17 terrific 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. Our group of physicians have worked closely together for many years. None of the physicians in our group have ever left to join other groups. I have also worked with the same nurse (Bernadette) since I moved to Atlanta in 1997. For many families, more practical matters about our office 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 to better the outcomes for children with inflammatory bowel disease – 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 (both adults). I like to read, walk/hike, bike, swim, and play tennis with my free time. I do not have any financial relationships with pharmaceutical companies or other financial relationships to disclose. I have helped enroll patients in industry-sponsored research studies.

Never quite right

After esophageal atresia (EA) repair, problems with reflux and dysphagia effect up to 75-100% of patients.  A new study, JPGN 2013; 56: 609-14, helps provide some understanding why the esophagus is never quite right in these patients.

High resolution esophageal manometry (HREM) was performed in 40 patients with a median age of 8 years at three centers. Data was obtained primarily by chart review; in addition, symptomatology at the time of HRE#M was evaluated through a self-assessment questionnaire completed by the child or his primary caregiver.  35 patients had type C EA which typically accounts for 80-85% of all EA cases. Type C EA refers to a proximal esophageal pouch and a distal tracheoesophageal fistula (TEF).  5 patients had type A. Type A EA is an EA without a distal TEF. At the time of the HREM, 7 (18%) were considered asymptomatic.

Findings:

  • Three different motility patterns were identified: aperistalsis in 15 (38%), pressurization in 6 (15%), and distal contractions in 19 (47%).
  • Aperistalsis occurred primarily in patients with long-gap defects and/or following anastomotic leaks. 8 of 15 patients with aperistalsis had undergone fundoplication.
  • Pressurization (as shown in Figure 1) was when contraction of the entire esophageal body  occurred at once rather than in a progressive manner from proximal to distal esophagus. Distal contraction pattern indicated an absence of proximal esophageal contractions. 4 of 6 patients with pressurization pattern had undergone previous fundoplication.
  • Motility patterns were not predictive of symptoms.  Asymptomatic patients were noted with all three patterns.  However, gastroesophageal symptoms predominated in the aperistalsis group.  Dysphagia was frequent in all three groups.

Study limitations included retrospective data, and small numbers of patients. Furthermore, in patients with long-standing esophageal problems, “asymptomatic” may be related to the patient not knowing what “normal” feels like and may be related to compensatory behaviors.

While HREM explains the pathophysiology in EA patients, given the lack of effective medical treatments for motility disturbances, upper endoscopy is likely to be more useful for clinical management by identifying esophagitis and possibly Barrett’s esophagus.

Related blog post:

Barrett’s Esophagus –refer to cardiology?

According to a study which examined cause-specific mortality, patients with Barrett’s esophagus may be better off following up with a cardiologist than a gastroenterologist (Gastroenterol 2013; 144: 1375-83).

This study derived data from UK’s Clinical Practice Research Datalink.  8448 patients with Barrett’s esophagus were matched with 155,212 controls based on age, sex and general practice.

Key findings:

  • Patients with BE had increased risk of death from esophageal cancer leading to a 10-year risk of 1.9%.  The absolute mortality rate due to esophageal cancer was 1.44 per 1000 person-years.  Compared to the general population, this was a 4.5 fold relative increase.
  • Ischemic heart disease resulted in 168 patient deaths, nearly 4-fold the number that died of esophageal cancer.
  • Overall, individuals with Barrett’s esophagus had a 21% relative increased risk of all causes of death; the majority were not due to esophageal cancer.  32% were related to circulatory disorders, 24% were due to nonesophageal cancer, and 15% were due to respiratory disease.

While this was a large study, there remain several limitations; most of these are due to reliance on electronic records for the diagnosis of Barrett’s.  Also, some individuals with Barrett’s may have been identified due to other high risk conditions such as cirrhosis (endoscopy for varicose) which could contribute to excess mortality.  In addition, many controls likely had undiagnosed Barrett’s.  Even the attribution of the cause of death can be quite difficult, especially with a database study.

Nevertheless, the population-based setting likely means that the results are likely meaningful to a broad population.

Take-home message: While Barrett’s esophagus increases the risk of death from esophageal cancer, it is possible that strategies which focus on nonesophageal causes of death may be more effective than esophageal surveillance for increasing longevity.

Related blog entries:

The Pediatric Nutrionist Blog

One of my colleagues, Kipp Ellsworth, at Children’s Healthcare of Atlanta has started a pediatric nutrition blog: 

The Pediatric Nutritionist | Covering the world of infant, child … (www.childrensnutrition.org)

The site contains:

  • Core lectures section containing several presentations addressing the basics of pediatric nutrition
  • Feature Articles (long-form articles covering expansive clinical nutrition topics)
  • Protocol Development (articles covering institutional efforts to develop nutrition support protocols for various populations)
  • Journal Club
  • Clinical Vignettes (short-form articles or discussions on issues facing  clinical practice)

I’ve reviewed the site and I think it will be a useful resource for pediatric gastroenterology providers as well as general pediatricians.  Kipp has had a twitter feed which has provided links to a large number of nutrition articles and this site is likely to be a helpful extension.  Already on the site, there are a few powerpoint lectures; the one on formulas for infants and children provides a particularly good overview.

Neutrophil function as a biomarker for Acute Liver Failure

More data on impaired neutrophil function in acute liver failure (ALF) and subacute liver failure (SALF) is available (Hepatology 2013; 57: 1142-52).

This study examined 15 ALF patients and 10 SALF patients in a cross-sectional case-control cohort design who were admitted to the liver ICU at King’s College Hospital between 2008-2010.  The median age for the ALF group was 33 and for the SALF group it was 52.5.  Ultimately 10 survived without liver transplantation; the remainder either died or underwent liver transplantation.

Neutrophil function was assessed on admission and then serially every 3-4 days in several ways; these assays were compared with 6 septic controls and 11 healthy controls.  Phagocytic activity was measured with a “Phagotest,” which quantifies opsonization of labeled E. coli. Oxidative burst was measured with the “Burtest,” which determines the percentage of phagocytic cells that produce a reactive oxygen species.  Other tests examined neutrophil phenotype and cytokine measurements (TNF-α, IL-1β, IL-6, CXC8/IL-8, IL-10, and IL-17).

Key findings:

  • Impaired neutrophil phagocytic activity in both ALF and SALF cohort on admission predicted non survival without liver transplant (p=0.01).
  • Neutrophil expression of CD-16 was significantly reduced in ALF cohort on day 1 (p<0.001).

Take-home message:

This study demonstrates specific defects in neutrophil function in ALF/SALF that are similar to impaired bactericidal function in severe sepsis.  Neutrophil function assays, while not available at the bedside at this time, are important biomarkers in ALF/SALF for increased susceptibility for sepsis and death.

Related blog posts:

Mixed-review for Thiopurines

In this era of biologic agents for inflammatory bowel disease (IBD), the estimation of the risks and the benefits of thiopurines has been changing (Clin Gastroenterol Hepatol 2013; 11: 395-97).

The referenced article is an editorial that reviews new data on thiopurines as well as provide a background for their usage.

Main points:

  • After the SONIC trial, the usage of combination therapy in many IBD patients has regained favor with the main question: “How long to continue combination therapy?”
  • STORI trial evaluated withdrawal of infliximab (IFX) in patients on combined therapy.  More than 40% of patients who were withdrawn from IFX relapsed at 1 year.
  • After >20 years of thiopurine usage, more data is available on both short-term and long-term risks/benefits.  The risk of lymphoma in IBD patients on thiopurines is “4-fold increased…in the 6 evaluated studies.” Nonmelenoma skin cancer risk is increased by a hazard ratio of 5.9 in ongoing users and 3.9 in past thiopurine users.
  • At the same time, more recent studies have lowered the expectation of benefit for thiopurines (AZTEC trial, Cosnes study).

Related references:

  • Cosnes et al. Gastroenterol 2012; 142: s161.
  • Gastroenterol 2012; 142: 63-70.
  • Med Clin North Am 2010; 94: 93-113.

Related blog links:

Frequency of Functional Pain Overlap in Pediatric Crohn’s Disease

If a patient with Crohn’s disease has pain, it may signal a flare-up of the inflammatory process.  Other causes like secondary infections, strictures, and functional pain need to be considered as well.  Functional pain can be particularly challenging.  A recent study reports on the prevalence of functional pain overlap in this setting (Inflamm Bowel Dis 2013; 19: 826-31).

This study prospectively enrolled 307 patients from two centers; it was a substudy to a cognitive behavioral therapy trial.

Patients in remission were defined by the following:

  • all normal laboratory findings:erythrocyte sedimentation rate <10, albumin >3.5, C-reactive protein <1 mg/dL
  • absence of clinical signs/symptoms of inflammatory bowel disease: 3 or less stools per day, no bloody stools, no nocturnal stools, no strictures, no concurrent steroid therapy
  • no escalation in medical therapy or clinical relapse in previous 6 months

Results: 139 of 307 patients had abdominal pain.  Among those with pain, 18 (13%) patients had functional abdominal pain (FAP). 10 of the 18 had either a colonoscopy or MRI in the previous year.  In these patients, the median PCDAI was 10.

This study noted a higher rate of depression in patients with both FAP and Crohn’s: 56%. This is compared with 29% of Crohn’s patients in remission without pain and 45% of Crohn’s patients with pain due to active disease.

Key points:

  • Pain with or without active disease can lead to an overestimation of disease activity based on PCDAI.
  • Depression is common in patients with pain, regardless of etiology
  • Current diagnostic criteria for FAP are flawed.  In fact, the Rome III criteria for FAP which specify absence of organic disease.
  • Biomarkers and imaging modalities are the best tools to exclude active disease.

Related blog links:

Treating Allergic Reactions to Infliximab

This week on the GI bulletin board there was a brief discussion about overcoming allergic/anaphylactic reactions to infliximab.  A reference and a thoughtful response by Athos Bousvaros (in italics) follows:

Inflamm Bowel Dis. 2001 Feb;7(1):34-7. Successful desensitization and therapeutic use of infliximab in adult and pediatric Crohn’s disease patients with prior anaphylactic reaction. Puchner TCKugathasan SKelly KJBinion DG.   

 IN summary:

1.  Premed with 4 days of steroids (1mg/kg up to 40mg), and hydrocortisone day of the infusion.

2.  Give two test doses (0.1 mg, 1 mg), each over 10 minutes,

3.  If no problems, run the infusion over 4 hours instead of two.

 

Getting antibodies to infliximab before the challenge may also be helpful.  If high levels of antibodies are present, the patient may be more likely to fail the challenge. WE can “rescue” about half our patients using this protocol, and keep them on infliximab. IMPORTANT that a physician is around during the challenge.

Given the potential for adverse reactions and the importance of not depleting useful treatments, it is definitely worthwhile to read the entire cited reference rather than the aforementioned summary.

Related blog entry:

Overcoming ATIs | gutsandgrowth

Hepatocellular Carcinoma after the Fontan Procedure

Given the fact that chronic liver disease and cirrhosis can develop in patients after the Fontan procedure, it comes as little surprise that cases of hepatocellular carcinoma (HCC) are being reported as well (NEJM 2013; 368: 1756-57).

This letter to editor describes four patients ages 24 to 42 who developed HCC following a classic Fontan or a variation.  Three of the four had very elevated alpha-fetoprotein levels; the lowest of the four patients was 106 ng/mL.  The letter notes that cirrhosis “may develop…approximately 11 to 15 years after a Fontan procedure; an incidence of cancer of 1.5 to 5.0% per year” is estimated after development of cirrhosis based on previous studies.

The letter also describes difficulties with regard to potential screening and treatment.

Related blog entry/references:

Low Ceruloplasmin Levels in Pediatric NAFLD

Pediatric patients with nonalcoholic fatty liver disease (NAFLD) undergo workup to exclude underlying diseases.  For many patients, this may include screening for Wilson’s disease with a ceruloplasmin level.  In a recent study, lower ceruloplasmin in 100 pediatric patients with NAFLD were associated with more severe NAFLD (JPGN 2013; 56: 370-75).

All patients had measurements of copper, iron, ceruloplasmin, transferrin ferroxidase activity, and ferritin; these assays were from archival serum samples from a cohort with biopsy-proven NAFLD. These patients had undergone testing for other etiologies of liver disease.

The authors were trying to determine if oxidative stress and its association with iron or copper may be playing a role in the severity of NAFLD.  Those with lower severity NAFLD score (< 5) had a mean ceruloplasmin of 36.4 mg/dL (standard deviation 5.3); in contrast,  those with higher severity NAFLD score (≥5) who had a mean ceruloplasmin of 28.1 mg/dL (standard deviation 7.2).  That is, there was an inverse association between ceruloplasmin levels and the severity of NAFLD score.  Lower ceruloplasmin was associated with increased inflammation, more ballooning histology, and more steatosis.

Key point:

Lower ceruloplasmin (<28.6 mg/dL) had a 92% specificity and 76% sensitivity for identifying more severe NAFLD.  Thus, even a borderline-low ceruloplasmin that does not suggest Wilson’s disease may be useful in discriminating children more likely to need a liver biopsy.

Related blog entry:

NAFLD Guidelines 2012 | gutsandgrowth