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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.

Cardiovascular disease for the entire family

This month’s Journal of Pediatrics features an article for the entire family (J Pediatr 2012; 160: 590-7 [editorial pg 539]).  The authors demonstrate that children screened for cholesterol can serve as an index case for the entire family.  During a 26-year prospective followup of 852 pediatric patients (5-19 years old at enrollment) from Cincinnati, the authors assessed relationships of childhood risk factors with parental cardiovascular disease (CVD), type 2 diabetes (T2DM), and high blood pressure (HBP).

  • Pediatric HBP and low HDL cholesterol were predictive of parental CVD ≤age 50
  • Pediatric HBP and high triglycerides were predictive of parental CVD ≤age 60
  • Pediatric high triglycerides and high LDL cholesterol were predictive of parental CVD ≤age 66

The related editorial reviews large studies regarding lipid assessments, including the Bogalusa study with more than 3000 children and the Muscatine study with more than 14,000 children.  In addition, the editorial reviews the recommendations from an expert pediatric panel which suggested screening all children for dyslipidemia between 9 and 11 years. Interestingly, the editorial reviews the fact that screening for cholesterol has not been shown to harm children.  “The evidence is not sufficient to demonstrate any adverse affects.”

Although no harm has been proven, the expert recommendations do not have prospective data demonstrating benefit either.  While it is known that atherosclerotic lesions, including fatty streaks and calcifications, can develop in childhood, it is not known that current treatment strategies will improve long-term outcomes.  This study, however, provides an additional rationale for screening; namely, by identifying children with dyslipidemia, primary care providers can identify parents with cardiovascular disease who are more likely to benefit from urgent intervention.

Additional references:

  • http://hin.nhlbi.nih.gov/atpiii/calculator.asp?usertype=prof (cholesterol risk calculator)
  • Pediatrics 2011; 128 (suppl 5): S213-56.  Expert panel guidelines for cardiovascular health and risk reduction in children and adolescents.
  • -NEJM 2011; 365: 2078.  Use of statins to lower LDL to 60-70 range halted progression of coronary artery disease.
  • -Pediatrics 2007; 120: e189, e215.  US Preventive Services Task Force:  “the evidence is insufficient to recommend for or against routine screening for lipid disorders” up to age 20.  Consider pediatric drug Rx:
    1. After dietary failure
    2. LDL >190
    3. LDL >160 & FHx of CVD before age 55
    4. triglycerides >250-500 persistently
  • Pediatric Nutrition Handbook AAP Lipid types:type I -increased trig  (rare)
    type IIa -increased chol & LDL
    (most common)
       Homozygous: chol >500
         xanthomas before 10 yrs, vascular dz before age 20
       Heterozygotes with lower chol
    type IIb -elevated trig & chol/LDL
    (3rd most common)
    type III -abnormal LDL density (rare)
    type IV -elevated trig (2nd most common)
         may be increased with diabetes, obesity, inadequate fasting; may need to study parents to establish dx
    type V -increased trig/VLDL (rare)
         exclude nephrotic synd, hypothyroid, diabetes

Save a life with free allergy education

Food allergy affects 4-8% of children and allergic reactions can be fatal.  In fact, the main cause of poor outcome with accidental food allergy exposure is delay in the use of epinephrine.  To improve parental knowledge and overall management of food allergies, a group of allergists, nurses and dieticians has developed and validated educational materials (J Pediatr 2012; 160: 651-6).  In addition, they have made these materials available at no cost online:

To validate their materials, the authors enrolled 60 parents of newly referred children with a prior food allergy.  The measured outcome was demonstration of an autoinjector for epinephrine.  The correct number of steps in the use of the autoinjector increased from a 3.4 to 5.95 score (max score 6).  In addition, at 1 year, the score remained high, 5.47.  Knowledge tests improved as well: from 9.2 to 12.4 (out of 15); at one year, the score was 12.7.  On a practical basis, the frequency of allergic reactions was reduced as well.  The annualized allergic reaction rate dropped from 1.77 (historical data) to 0.42 after the instruction.

The article also relates that some of the material relied on previous educational material, in particular the food allergy emergency plan available from the Food Allergy & Anaphylaxis Network (www.foodallergy.org).

Materials available include information on specific allergic disorders, avoiding allergens, management in and outside home, and living a safe/healthy life.  In addition, an educational video is available.

Additional references:

  • -Bock SA et al. J Allergy Clin Immunol 2007; 119: 1016-8. Poor outcome with accidental food allergy exposure is delay in the use of epinephrine.
  • -J Pediatr 2011; 158: 578.  Oral food challenges allowed 84% to return foods to diet.  n=125.
  • -Clin Gastro & Hep 2010; 8: 755.  Review of food allergy (vs intolerance) in adults.  Gives list of hypoallergenic diet , pg 758.
  • -Pediatrics 2009; 124: 1549-55.  3.9% of US kids w food allergy.  Nat’l surveys.
  • -NEJM 2008; 359: 1252 Review. Usual age of resolution: eggs  @ 7yr (75%), milk @ 5yr (76%); wheat/soy -rarely cause IgE-mediated allergies 80% resolve by 5yrs>  More  persistent allergens:  peanuts/tree nuts/sesame seeds = persistent in 80-90% at 5yrs, fish = persistent.
  • -Pediatrics 2003; 111: 1591-1680.  (supplement) Pediatric Good Allergy symposium
  • -Pediatrics 2003; 111:829-835. Infants c food-induced enterocolitis often have multiple food allergies (cereal, veggie, poultry, meat)  IgE based tests are negative (skin prick & IgE Abs
  • -Gastroenterology 2001; 120: 1023-25; 1026-40.  AGA position paper; technical review.
  • -J Allergy Clin Immmunol 1999; 103: 717-728 &981-9.  Pathogenesis &  Dx/ mgt.

Guidelines for Eosinophilic Esophagitis

For a little while, I’ve meant to complete a post on the EoE guidelines published last fall (J Allergy Clin Immunol 2011; 128: 3-20).  This article, based on the input of 33 physicians with EoE expertise, provides a lot of depth to this unfolding area in pediatric gastroenterology.

Diagnosis of EoE. The authors caution that this diagnosis is not a histologic diagnosis as a number of entities can cause esophageal eosinophilia; at the same time, a minimum number of eosinophils, 15/hpf, is a necessary diagnostic threshold.  A small number of patients may have EoE with fewer than 15/hpf, including PPI-responsive EoE, inadequate biopsy sampling, seasonal variation, or partial treatment (eg. patient on corticosteroids).

How many biopsies?  In one cited study in the article, 2, 3, and 6 biopsies had sensitivity of 84%, 97%, and 100% respectively.  Endoscopic biopsies remain the only reliable diagnostic test.

Why are there a subset of PPI-responsive EoE patients?  Potential explanations include improvement in immune-activation after healing of esophageal mucosa, inherent anti-inflammatory property of PPIs, or due to pitfalls in current diagnostic testing.  Due to recognition of this disorder, pH testing may be needed in many patients with suspected EoE.  Even still, the authors note that “PPI responsiveness or diagnostic testing (pH monitoring) might not adequately distinguish GERD and EoE.”

How useful are genotypic features?  Clinical  use of genotypes is not feasible at this time.  However, it is anticipated that esophageal gene expression will emerge as one way to differentiate EoE from other conditions and to determine optimal treatments.

What type of allergy evaluation? The majority of EoE patients have concurrent atopic diseases, including rhinitis, asthma, and eczema.  Thorough evaluation by an allergist (or immunologist) is recommended.  Specific recommendations: skin prick testing (SPT), serum IgE for immediate-type food allergy.  Atopy patch testing (APT) has high negative predictive values, >90%, except for milk which is ~50%.  APT needs to “be standardized and validated.”

Biomarkers? “Insufficient evidence to support any peripheral marker” including cytokines, and IgE (total).

Treatment –PPI: PPIs are useful to distinguish GERD as well as PPI-responsive EoE from EoE requiring other treatments.  They also help with symptomatic treatment in some patients who have secondary GERD.  Recommended dose in children 1 mg/kg/dose BID.

Treatment –Dietary: Three dietary regimens have potential effectiveness: 1) selective food diet based on allergy testing, 2) dietary restriction of the most likely food antigens (eg. six food group diet elimination) and 3) strict amino acid based diet.  Tolerance of foods that have been shown previously to provoke EoE is unlikely to develop in the majority of EoE patients.

Treatment –Corticosteroids: Corticosteroids are effective but when discontinued EoE almost always recurs.  Systemic corticosteroids can be particularly useful when severe dysphagia is present.  With severe endoscopic findings, a course of corticosteroids may help reduce the need for dilatation or lessen the risk.  Long-term use of systemic steroids is not recommended.  Topical steroids should be considered in all patients with EoE.  Recommended doses are given.

  • For fluticasone:  88-440 μg 2-4 times per day (max 880 μg BID)
  • For budesonide: 1mg daily (<10 y) and 2 mg daily (≥10 y)
Treatment –Dilation:  Dilation can provide relief of dysphagia.  In most cases, medical or dietary therapy should be attempted prior to use of dilation.  Goal of 15-18 mm.  Practical advice (not validated in studies): Limit dilation progression per session to 3 mm or less after resistance has been encountered.
Treatment –Alternatives:  Cromolyn, leukotriene receptor antagonists, or immunosuppressive agents (eg azathioprine, 6-mercaptopurine) are “not recommended.”
Complications: Perforations (spontaneous & procedure-related), food impactions, strictures, and narrow caliber esophagus.  There has not been evidence of an increased esophageal cancer risk in EoE patients to date.
Unresolved issues: Despite the extensive consensus on many of these issues, the conclusions inform the reader of how far we need to go.  Some of the unresolved questions include such basic problems:
  • “Importance of treating asymptomatic patients”
  • “Natural history of EoE and rates and predictive indexes of complications”
  • “Accuracy of skin prick and patch testing”
  • “Optimal end points of treatment”

Previous related blog posts:

The undiscovered country

Eosinophilic Esophagitis -Six Food Group Diet

Practical information on EoE for families:

http://www.ccdhc.org/diseases/EoE.html

Biomarkers identify patients who benefit and how

Fecal calprotectin and serum CRP levels are helping to identify which patients benefit most from biologic therapies, how frequently to dose individuals and how well inflammation correlates with changes in CDAI.  Several abstracts from ACG highlight these issues:

Abstract #1175: Fecal calprotectin concentration and clinical remission in patients with active Crohn’s disease treated with certolizumab pegol: results from PRECiSE 1 (Sandborn W et al).

Abstract #1164: Baseline C-reactive protein is associated with disease progression in  patients with Crohn’s disease (Colmbel J-F et al).

Abstract #1165: Association of baseline C-reactive protein with maintenance of remission in patients with moderate to severe Crohn’s disease treated with adalimumab (Sandborn W et al)

Abstract 1175 uses a post hoc analysis of patients with active Crohn’s disease (CD) who were treated with certolizumab or placebo for 26 weeks.  Baseline calprotectin concentrations were higher in patients who achieved remission.  Another interesting finding of this study was that placebo patients did not have improvement in calprotectin levels.  So, even though some patients  had improvement in CDAI scores, indicating subjective improvement, inflammatory activity did not decline.  This is another indicator of how flawed a CDAI is for indicating the effectiveness of an IBD therapy.

Abstract 1164 looked at 238 patients with moderate to severe CD who were randomized to placebo arm in the CHARM study.  These patients were given open-label adalimumab for induction (80 mg week 0, 40 mg week 2) followed by blinded weekly placebo treatment from weeks 4-56 with a switch to open-label adalimumab after week 12 for a disease flare.  Higher baseline CRP levels in patients with moderate or severe CD were associated with higher disease scores after four weeks and after one year.  This suggests that a patient with higher CRP is more likely to have disease progression without adequate treatment.

Abstract 1165 examined the relationship between CRP and remission in CHARM patients. In the high baseline CRP group, 39 patients received adalimumab every other week, 28 weekly, and 34 received placebo.  In the low baseline CRP group, there were 42 every other week patients, 33 weekly, and 39 placebo patients.  In the high baseline CRP group, remission rates were 50% higher in the weekly treatment group compared to the every other week group.  Patients with low baseline CRP had similar results when treated weekly versus every other week.  Thus, patients with high baseline CRP are more likely to benefit from dose escalation and low CRP patients are more likely to have coexistent issues contributing to their symptoms (eg. IBS).

One other caveat: CRP production is geneticallly-determined and some patients do not make CRP in spite of active inflammation.

Related blog entries:

Food as medicine

Speed matters

Additional calprotectin references:

  • -IBD 2010; 16: 482. Calprotectin correlated with inflammation of ileum after pouch creation in children.
  • -IBD 2009; 12: 1851. Calprotectin was the only marker to correlate with endoscopic activity; n=134.
  • -JPGN 2009; 48: 48. Good sensitivity/specificity of calprotectin & lactoferrin. Up to 96% sensitivity & specificity.
  • -Clin Gastro & Hep 2008; 6: 1218. Lack of correlation between clinical symptoms and fecal biomarkers. However, biomarkers do correlate with mucosal/endoscopic disease. n=164.
  • -IBD 2008; 14: 1392. Monitoring IBD activity level c calprotectin & lactoferrin; n=15.
  • -IBD 2008; 14: 1229. Clinical utility in assessing histological relapse in kids. n=73 over 8yrs…may allow avoidance of invasive tests; cut off of 275mcg/gm had 97% sensitivity/neg pred value 85% pos pred value/specificity at predicting relapse.
  • -IBD 2008; 14: 669. Fecal calprotectin good at predicting relapse in pediatric IBD w cutoff of 400.

C-reactive protein references:

  • -J Pediatr 2011; 159: 340. CRP helps identify IBD.
  • -Clin Gastro & Hepatology 2011; 9: 421. CRP predicts response to IFX. n=718. those with high CRP had 91% response vs 83% in pts with NL CRP.
  • -Gastro 2004; 126: 1574-81. Crohn’s review. High CRP suggests likely response to anti-TNFα treatment.
  • -JPGN 2004; 38: 509-12. CRP more reliable than ESR for IBD.
  • -NEJM 1999; 340: 448. Review on acute phase reactants. CRP better than ESR as ESR is an indirect measure (resistance of plasma, due to fibrinogen, to the falling of RBCs) & broader range for CRP.

Magnetic resonance enterography for Crohn’s disease

Magnetic resonance enterography (MRE) has increasingly been recognized as an effective way to characterize small bowel disease in Crohn’s disease (Inflamm Bowel Dis 2012; 18: 520-28).

In this retrospective pediatric study, 95 patients with Crohn’s disease underwent MRE from 2006-2009.  As expected, terminal ileal disease was the most common site of involvement with 54%; this was followed by ileum with 19%, and jejunum with 17%.  Other findings included solitary jejunal inflammation (3.7%), small bowel stenosis (1.9%) fistula (1%), and abscess (1%).  Specific evidence of inflammation included contrast enhancement, bowel wall thickening or derangement of bowel wall shape.  The images in the article are excellent.

The main advantage of MRE over CT enterography (CTE) is the lack of ionizing radiation.  In addition, MRE can better detect soft tissue contrast suggestive of bowel wall edema.  This helps distinguish acute from chronic inflammation.  Obtaining an MRE is technically more challenging and more costly.  The youngest patient in the study was seven; though the authors note that the youngest patient they have performed MRE was six.

Additional references:

  • More imaging needed?
  • -JPGN 2010; 51: 603.  MRE for suspected IBD.  Useful in pediatric Crohn’s disease.
  • -IBD 2009; 15: 1635. U/S compared favorably with endoscopy in correlating postoperative recurrence with Crohn’s.
  • -Clin Gastro Hepatol 2006; 3: 1221. MRI as accurate in evaluating ileocolonic disease with flareups as endoscopy.
  • -IBD 2004; 10: 452-61. U/S was very helpful in identifying disease and complications.

Challenges with primary sclerosing cholangitis

Although primary sclerosing cholangitis (PSC) is an infrequent liver problem in pediatrics, it remains important.  PSC accounts for 2-3% of pediatric liver transplant cases.  A recent report updates some of the challenges for pediatric hepatologists (Shneider BL. Liver Transplantation 2012: 18: 277-81).

First the article examines some of the salient differences between children and adults.  The approach in adults may not apply well to children.  Some inherited diseases and immunologic defects may produce a similar clinical picture.   Specific differences include the following:

  • Defects in the adenosine triphosphate-binding cassette B4 (ABCB4 gene) (multidrug resistance protein 3) may cause a number of small-duct PSC in children
  • Cystic fibrosis can have a similar appearance
  • Overlap syndrome with autoimmune hepatitis is more common in children
  • Children with PSC often have higher alanine aminotransferase enzyme values than adults
  • Cholangiocarcinoma is rare in childhood, with 17 being the youngest reported case

Diagnosis usually requires, in addition to blood tests, cholangiography (eg MRCP), liver biopsy or both.  ERCP may not be needed depending on MRCP results.

Management: Pruritus may be managed with ursodeoxycholic acid (UDCA), bile acid binding resins, and rifampin.  Bone disease needs to be monitored along with fat soluble vitamin status.

  • While pruritus may improve with UDCA, high-dose UDCA (28-30mg/kg/day) has been associated with increased likelihood of negative endpoints.  It is not clear whether there may be detrimental effects at lower doses.
  • What about immunosuppression?  This (corticosteroids/thiopurines) is accepted in cases with AIH overlap.  Of course, what constitutes overlap is not certain.  So, in many cases, a trial of corticosteroids is considered.
  • Antibiotics?  Oral vancomycin has been tried in a small number with preliminary success.

As noted above, liver transplantation is a needed treatment in some cases. One concern with this approach has been recurrent PSC in about 10% at an average of 18 months after liver transplantation.

Additional references:

  • -Am J Gastro 2011; 106: 1638.  Use of high dose Urso increases risk of colonic neoplasia. n=150.
  • -Hepatology 2011; 54: 1842.  Guidelines on surveillance for PSC.  IF IBD yearly scope.  **Yearly U/S + CA 19-9 or yearly MRI.
  • -Liver Transplantation 201; 17: 925-933.  n=79 pediatric pts.  49% w IBD prior to OLT (46% w UC, 3%) & 9.8% developed IBD p OLT.  1 & 5yr survival for OLT 99% & 87%.  Recurrence in 9.8%.
  • -Clin Gastro & Hepatology 2011; 9: 434.  37% of PSC pts with CA 19-9 >129U/mL do NOT have cholangiocarcinoma.  n=7.
  • -Hepatology 2010; 51: 660-678.  update on dx/mgt.
  • -Gastroenterology 2010; 138: 1102.  genome associations with PSC.
  • -Hepatology 2009; 50: 808, 671 (ed).  Use of urso ~30/kg associated w WORSE outcome @5yrs. n=76 (& 74 controls)
  • -Clin Gastro & Hep 2009; 7:239. n=47 children w PSC.  59% w IBD, 25% w overlap syndrome
  • -JPGN 2008; 47: 61.  Use of oral vancomycin, 50mg/kg/day in patients with PSC/IBD was effective. n=14.
  • -Liver Tx 2008; 14: 735.  Review.  5 yr OLT survival 85%  ReTx rate higher (9.6% vs 4.9%).
  • -Hepatology 2008; 47: 9494-57.  Asymptomatic PSC common in AIH –might be higher than 10%.
  • -Gastroenterology 2008; 134: 975.  Natural hx/o small duct PSC in 83 pts (compared to controls).  Not likely increase in cholangiocarcinoma unless also large duct involvement.
  • -Gastroenterology 2008; 134: 706.  IAC is similar; IAC=IGG4 Associated Cholangitis
  • -Hepatology 2008; 47: 949.  8/79 w AIH also had PSC.
  • -J Pediatr 2007; 151: 255, 230.  association of CFTR mutations in PSC (26%); also present in disease control group with IBD (43%).
  • -Clin Gastro & Hep 2007; 5: 32.  Review vis-a-vis possible cholangiocarcinoma.
  • -Hepatology 2006; 44: 1063.  Review along w secondary causes.
  • -Liver Transplantation 2006; 12: 1813.  Recurrence post Tx 22% AIH, 18% PBC, 11% PSC.  (Review of 43 studies).
  • -Gastroenterology 2005; 129:1464.  High-dose actigall ineffective in 5 yr randomized controlled study.
  • -Gastroenterology 2003; 125: 1364.  Incidence of PSC.
  • -JPGN 2003; 37: 345 (57A). Use of vanco 50/kg/day x 4-6weeks in PSC, n=10, (56A) some pts c normal cholangiograms.
  • -Gastroenterology 2003; 124: 889. Urso prevents colon ca.
  • -Am J Gastro 2001; 96: 1558-62.  High dose UDCA, 25-30/kg/day may help long-term outlook
  • -JPGN 2001; 33:296. PSC-IBD.
  • -NEJM 2002; 346: 271-277.  case c Crohn’s.  PSC assoc c UC, celiac dz, pancreatic insufficiency.
  • -Ann Intern Med 2001; 134: 89-95.  Urso decreases colonic neoplasia in pts c UC & PSC.
    -NEJM 1997; 336: 691. Ursodeoxycolic acid & PSC.
  • -Gregorio et al. Autoimmune hepatitis/sclerosing cholangitis overlap syndrome in childhood: a 16-year prospective study. Hepatology 2001;33:544-553

NASPGHAN 2010 Pointers:
I. -“STOPSC criteria”: 2 of 3 diagnostic criteria needed:
1) elev GGT or alk phos
2) intra and/or extrahepatic bile duct irregularities on cholangiography (i.e. PTC, MRCP, ERCP) c/w PSC
3) liver biopsy abnormalities c/w chronic biliary injury

AND no evidence of a secondary cause of sclerosing cholangitis

 

II. SUMMARY OF KEY CLINICAL FEATURES:

 

  • -Sclerosing cholangitis  is associated with IBD, autoimmune and connective tissue disorders, abnormalities of immune function (i.e. immunodeficiencies, GvHD), infiltrative disorders (i.e. Langerhans cell histiocytosis, lymphoma).
  • -PSC may sometimes affect only small intrahepatic bile duct (“small duct PSC”), which may have a better outcome based on adult studies
  • -PSC may have overlapping features of AIH  (“autoimmune sclerosing cholangitis”)
  • -IgG4 –associated cholangitis: patients appear to have PSC with elev IgG4.  They seem to respond very well to steroid therapy in adult studies
  • -No therapy of proven benefit for PSC (ursodiol, antibiotics), some case series have suggested antibiotics may help PSC
  • -5 times higher rate of Colorectal Ca when UC pt has PSC.  Consider yearly endoscopy

 

Preventing Cancer in patients with Barrett’s Esophagus

Though Barrett’s esophagus is rare in pediatric gastroenterology, concerns about esophageal cancer are fairly frequent.  In addition, some conditions that increase the risk of esophageal adenocarcinoma start in childhood.

One way to lessen the risk of Barrett’s esophagus in adults is through the use of medications (Gastroenterology 2012; 142: 442-52).  This study was a pooled analysis of six population-based trials with a total of 1226 esophageal adenocarcinoma (EAC) patients and 1140 esophagogastric junctional adenocarcinoma (EGJA) patients.  NSAIDs (aspirin and nonaspirin) lowered the risk of both EAC and EGJA, with OR of 0.68 and 0.83 respectively.

Although this study suggests a possible role for NSAIDs in preventing cancer in patients with Barrett’s esophagus, the risks and benefits for this intervention need to be individualized.

Related previous blog post: More bad news for smokers

Additional references:

  • -Gastroenterology 2011; 141: 2000. Lower risk of Barrett’s in pts taking NSAIDs & statins. n=570.
  • -Gastroenterology 2011; 141: 1179. Overall, patients with BE and LGD have a low annual incidence of EAC, similar to nondysplastic BE. There are no risk factors for progression and there is significant interobserver variation in diagnosis, even among expert pathologists.
  • -NEJM 2011; 365: 1375. Large Danish study, n=11028. Lower incidence of Barrett’s than previous estimates. Relative risk of 11.3 compared to general population for adenoca of Esophagus with absolute annual risk of 0.12%. Barrett’s patients have the same life expectancy as general population (ed. pg 1437). Detecting cancer only ~1 in 1460 scopes with screening whereas Barrett’s detected in 10% of pts.
  • -Gastroenterology 2011; 141: 417, 460. Durable effects of ablation, n=127..
  • -Gastroenterology 2011; 140: 1084. AGA statement on Barrett’s . Recs screening only in those with multiple risk factors (age 50, male, chronic GERD, white, incr BMI)
  • -Clin Gastro & Hep 2010; 8: 565. Guidelines suggest that screening for Barrett’s is not justified w/o alarm symptoms (dysphagia, odynophagia, wt loss, anemia, hematemesis)
  • -Gastroenterology 2010; 138: 2260. n=11,823. Decrease risk of esophageal adenoCa in patients taking NSAIDs & statins.
  • -Gastroenterology 2010; 138: 854. Nice review.
  • -Gastroenterology 2010; 138: 5. Survival equivalent to general population according to Mayo study, n=366. In Barrett’s patients, leading cause of death was cardiovascular (28%). Esophageal cancer resulted in 7% of deaths. Study presented at ACG Oct 26, 2009.
  • -Clin Gastro & Hepatology 2009; 7: 1266. no benefit from surgery for Barrett’s & unclear if chemoprevention works.
  • -Gastroenterology 2009; 137: 763. Suggests surveillance with Barrett’s is not beneficial.
  • -NEJM 2009; 360: 2277, 2353.. Radiofrequency ablation can be effective.
  • -Gut 2008; 57: 1200-06. Utility of endoscopic Rx.
  • -Clin Gastro & Hep 2008; 6: 1206; editorials: 1180, 1181, 1183.. n=2107 with Barrett’s. 79 w surgery and 80 w endoscopic Rx.
  • -Gastro & Hep 2006; 2: 468. 2-8% of pts in general population have Barrett’s. >90% of ptsc Barretts will never develop cancer. Screening has not been proven to be effective in lowering rate of death from cancer. ~40% of US population has heartburn; only 8000-9000/yr develop esoph adenoCa. Also, the presence of Barrett esophagus does not decrease life expectancy.
  • -Gastroenterology 2005; 129: 1825-31. 1.6% incidence of BE in adult Swedish population. Alcohol, smoking increase risk.

Disruption of KLF4 is the real villain for gastric cancer

The only reason I’m posting this article is the word “Villin” in the title of the article (Gastroenterology 2012; 142: 531-42); I wondered what this was.  In this study, the authors show that “disruption of KLF4 in villin-positive gastric progenitor cells promotes the formation and progression of tumors in the antrum of mice.”  For the uninitiated,  an editorial on pages 424-27 of the same issue explains the entire article and the significance of the findings.

Kruppel-like factor 4 (KLF4) is a protein in multiple tissues that is important in cell differentiation, inflammation, and carcinogenesis.  Villin is an actin-bundling protein found in the apical brush border of absorptive tissue.  Villin-expressing gastric progenitor cells are typically quiescent but undergo division during inflammatory insults.

This is important in understanding gastric cancer because for a long time it was unclear why cancer would develop in the stomach where there is frequent turnover of the mucosa.  It is likely that more quiescent cells live long enough to accumulate cancer-promoting mutations/changes.  This study adds support to this hypothesis, at least in mice.

Drug levels for inflammatory bowel disease

In many conditions, drug levels are helpful to make sure the patient receives an adequate dose for the indication.  When we treat infections or seizures, drug levels predict the effectiveness of the medication and allow dosing adjustments to improve responses as well as to lower toxicity. Drug levels are helpful in inflammatory bowel disease (IBD) as well.  Drug levels may help with thiopurine dosing and with infliximab (IFX) dosing.

Infliximab (IFX) levels can guide therapy (Scand J Gastroeneterol 2011; 46: 310-18). This study examined 106 patients (85 with CD and 21 with UC) over a ten-year period. In this cohort, patients received concurrent hydrocortisone, acetaminophen, and cetirizine to prevent acute reactions and to try to limit anti-infliximab antibodies (ATI), also called anti-human antichimeric antibodies (HACA).  Infusion intervals ranged from 4-12 weeks.

69% of Crohn’s patients maintained response to IFX and 48% of UC patients.  Infliximab trough levels were significantly increased among patients who maintained their response.  A cutoff value of 0.5 μg/mL was defined as clinically relevant for IFX trough concentrations for Crohn’s patients and for UC the cutoff was 0.8 μg/mL .  Trough levels below this cutoff were 86% sensitive and 85% specific for identifying loss of response.  The overall accuracy for the test was 87% in identifying loss of response.

Also, ATIs were significantly higher in CD patients who had lost response to infliximab.  Patients who had been “re-treated,” were significantly more likely to have developed ATIs.  “Re-treated” was defined as having interruption of IFX treatment more than 6 months.

These specific cutoff values apply to the radioimmunoassay technique for measuring IFX and ATI.  These values may not extrapolate to ELISA assays.  At the same time, the findings suggest a practical approach in patients with symptoms while receiving IFX:

  • Check IFX level (at trough or at 4 weeks)
  • If low level and no ATI, likely to respond to dose escalation
  • If low level but positive for ATI, not likely to respond to dose escalation
  • Do not assume symptoms are due to drug failure; reassess with imaging &/or scope. Consider alternate etiologies (eg infections, stricture, celiac, IBS).
  • Cotherapy with an immunomodulator reduces ATIs and boosts levels of IFX.
More usage of IFX and ATI levels is likely; however, cost issues preclude frequent measurements.

Additional references:

  • Only one chance to make first impression.  Previous blog entry on use of infliximab.
  • -Clin Gastro & Hepatology 2011; 9: 395. Do not assume symptoms are due to drug failure -reassess with imaging &/or scope. Consider alternate etiologies (eg infections, stricture, celiac, IBS). Check IFX level –if >12 @ 4weeks or >1.4 mcg/mL at trough –>predicts good response.  If +HACA, ~90% response with alternative TNF.  In those with low level, 86% responded to dose escalation.
  • -DDW 2011, Abstract #772. If loss of response to IFX, **confirm active dz (labs, scope) & not due to CDT. **check HACA –if +, only 10-20% chance of responding to dose escalation; better chance of responding to similar agent **check IFX week 4 level, if low (& neg HACA) then 90% respond to dose escalation
  • -NEJM 2010; 362:1383-1395. SONIC study.  Patients with moderate-to-severe Crohn’s disease who were treated with infliximab plus azathioprine or infliximab monotherapy were more likely to have a corticosteroid-free clinical remission than those receiving azathioprine monotherapy.
  • -Gut 2010; 59: 49-54. Trough IFX levels in UC. n=115. Antibody status can only be measured at trough levels. Undetectable trough level (<1.4 mcg/mL) associated with lower remission (15% vs 69%) and lower endoscopic response (28% vs 76%) & higher colectomy rate (55% vs. 7%).
  • -Gastroenterology 2010; 139: 344 (review of above Gut article). Similar to Crohn’s disease: 82% remission with detectable trough vs 6% w/o detectable level.
  • Lancet 354 (9194): 1932–9. doi:10.1016/S0140-6736(99)05246-0PMID 10622295.”Infliximab (chimeric anti-tumour necrosis factor alpha monoclonal antibody) versus placebo in rheumatoid arthritis patients receiving concomitant methotrexate: a randomised phase III trial. ATTRACT Study Group”.
  • -Am J Gastroenterol 2010; 105: 1133-39. If lack/loss of response, may need dose escalation with humira or Cimzia (q2weeks):
  • -IBD 2011; 17: 141-51. Loss of response to biologics.
  • -Gastro & Hep 2008; 4: 12. “primary nonresponse can be determined after 2 doses” in table reiterating AGA consensus guidelines. 85% of responders show benefit by 2weeks & all responders benefit c/in 6 weeks (Am J Gastro 2001; 96: S303). Worsening Sx despite infliximab indicates need to look for stricture, infxn, etc.
  • -Clin Gastro & Hep 2006; 4: 1248. Clinical remission associated with measurable infliximab troughs; thus, if no measurable trough, increase dose or shorten interval. If level detected & no response, unlikely to respnd to TNF class. Also, concurrent immunomodulators were not helpful.
  • -Am J Gastro 2010; 105: 2617 (Oussalah et al). 2-3yrs 41% IFX failure in UC. withdrawal of AZA increase loss of response –7x more likely
  • -Am J Gastro ; 105: 1133-40. n=155. 23% ATI -92% respond to med change, 17% respond to dose change. Level <12 @ 4weeks, 86% respond to dose change
  • -Gut 2010; 59: 1363. n=121. Co-treatment helped reduce complications & flares relative to monotherapy (& azathioprine appeared to be more effective than methotrexate).

Breastfed babies less likely to develop fatty liver

In a study presented at AASLD meeting (San Francisco, November 4, 2011), Ayonrinde et al followed 1170 children in Australia (www.rainstudy.org.au) from birth to age 17. Anthropometric measurements were followed regularly and a liver ultrasound was obtained at age 17.  Patients who reported consuming alcohol were excluded.

By age 17, 16% of girls and 10% of boys had developed nonalcoholic fatty liver disease (NAFLD). Breastfeeding was highly protective.  Infants breastfed for more than 6 months were less than half as likely to develop NAFLD.

As noted in this blog recently (A liver disease tsunami), fatty liver disease is a huge problem.  While this study may not influence the choice to breastfeed in many cases, it highlights yet another advantage of breastfeeding. 

Previous post on breastfeeding:

More evidence that breastfeeding improves cognitive development