How Many Eosinophils Indicate Eosinophilic Gastroenteritis or Colitis?

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A recent study (Z Kiss et al. JPGN 2018; 67: 6-12) provides more data on normative values for eosinophil counts in the GI tract.  For their report, the authors reviewed 3 databases for a systematic search of the literature. They screened 1316 abstracts but found only 8 articles with complete/relevant data.  Among these 8 articles, data regarding each segment of the GI tract was present in as few as 3 articles and as many as 6 articles. The authors provide confidence intervals (CIs) and prediction intervals (PIs); the latter account for the wider uncertainty due to insufficient data.

Key points:

Normal eosinophil cell number per high-power field (HPF area = 0.2 mm squared):

  • Duodenum 8.26 with CI 4.71-11.8 and PI of 0 to 20.57
  • Terminal ileum 11.52 with CI 7.21-15.83 and PI of 0 to 60.64
  • Cecum 14.12 with CI 9.05-19.19 and PI of 0 to 38.64
  • Ascending colon 13.25 with CI 8.65-17.86 and PI of 0 to 35.42
  • Transverse colon 11.52 with CI 7.80-15.23 and PI of 0 to 25.85
  • Descending colon 10.32 with CI 7.22-13.42 and PI of 0 to 49.10
  • Sigmoid colon 8.80 with CI 6.82-10.77 and PI of 0 to 32.49
  • Rectum 7.39 with CI 4.20-10.59 and PI of 0 to 22.33

Other points:

  • The authors note that eos/HPFis a flawed measurement due to technical parameters of the microscope.  Some HPFs are bigger than others –this could affect eosinophil count up to 5-fold.  The authors specify an HPF to be =0.2 mm squared.
  • Obtaining appropriate mucosal samples for normal number of eosinophil counts can be difficult.  Even patients with functional disorders like irritable bowel syndrome and nonulcer dyspepsia could have abnormal numbers of eosinophils.

My take: These numbers of expected eosinophil counts for pediatric histology are a good starting point.  The prediction intervals remain large due to insufficient data.

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Gibbs Gardens

Pediatric NAFLD: You Don’t Have to be Obese/Overweight to Have Fatty Liver Disease (but it helps)

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A recent study (P Kumar et al. JPGN 2018; 67: 75-9) examined suspected NAFLD in 12 to 18 year olds using data from NHANES. In the analysed cohort, there were 124 suspected NAFLD and 1385 without suspicion of NAFLD.  This subset was weight to represent a U.S. population of over 18 million.

Key definitions:

  • Suspected NAFLD was defined by abnormal ALT (>25.8 U/L for boys and >22.1 U/L for girls) who did not have another explanation (eg. viral hepatitis, medication)
  • Lean BMI was defined by BMI less than 85th% for age
  • Hypertriglyceridemia ≥ 150
  • Low HDL ≤ 40 mg/dL
  • HOMA-IR =fasting glucose x insulin (microU/mL) divided by 405. Insulin resistance was defined as HOMA-IR ≥ 3

Key findings:

  • Suspected NAFLD affects ~8% of lean adolescents in the U.S.
  • Hypertriglyceridemia was noted in 10 of 124 suspected NAFLD and was a risk factor (P=0.028) as was Low HDL which occurred in 15 (P=0.016) and IR which occurred in 43 (P=0.053)

My take: Elevated ALT, a marker for fatty liver disease, is common even in adolescents without obesity. Elevated triglycerides, low HDL, and insulin resistance are all risk factors for suspected NAFLD in non-overweight/non-obese teens.

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Cumberland Island 2018

MRE Does Not Fare Well at Detecting Lesions Evident on Upper Endoscopy

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A recent study (PC Church et al. JPGN 2018; 67: 53-8) examined how well EGD findings were detected by MRE in 188 children (mean age 14 years).

Key findings:

  • EGD was macroscopically abnormal in 93 (49%) with ulcerations being the most common abnormality in 66 (35%).
  • In contrast, the local radiologist identified UGI inflammation in 7 (4%) and the central radiologists identied UGI inflammation in 20 (22%).  “There was no agreement between local and central radiologists when examining the UGI as a whole (κ=-0.02, P-0.59)”
  • The local radiologists “correctly identified only 5 of 93 (8%) patients with UGI findings on EGD.”  The central radiologists “correctly identified 9 of 45 (30%) patients with UGI findings on EGD.”

The authors state that “the Porto criteria mandate the performance of EGD for all pediatric patients suspected of having IBD. Our study has demonstrated that MRE cannot be relied upon as the sole method of evaluating the UGI.”

My take: For those who take care of children with IBD, this study will not come as a surprise as many of the UGI findings (found at endoscopy) are subtle.  This study does quantify the much higher sensitivity of endoscopic evaluation and is similar to studies that have compared capsule endoscopy to MRE.

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Cumberland Island 2018

Pediatric Pancreatitis -Working Group Nutritional Recommendations

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Abstract Link: Nutritional Considerations in Pediatric Pancreatitis: A Position Paper from the NASPHAN Pancreas Committee and ESPHAN Cystic Fibrosis/Pancreas Working Group.

M Abu-El-Haija et al. JPGN 2018; 67: 131-43.  This working group made ~27 recommendations (summarized in Table 1) and indicated the quality of evidence supporting the recommendation as well as the agreement among team members –virtually all received at least 12 of 13 votes.

Here are the ones that grabbed my attention:

For Acute Pancreatitis (AP):

  • 1a & 1aa. Children with mild AP should be started on a regular diet –preferably via mouth as compared to nasogastric route
  • 1b. Enteral nutrition (EN) should be attempted in children with severe AP within 72 hours from presentation, once deemed hemodynamically stable.
  • 1.4 Even in severe AP, jejunal tube feeding should be reserved for those unable to tolerate oral or NG tube feeding

For Acute Recurrent Pancreatitis (ARP):

  • 2.1a & 2.1b. Children should receive a regular-fat diet in between bouts of ARP and a regular-fat diet can safely be started within 1 week after the onset of a bout of AP (except in those with very elevated triglycerids (>1000 mg/dL)
  • 2.2a & 2.3a. PERT is NOT recommended in children with ARP without eocrine pancreatic insufficiency (EPI). Antioxidants are NOT recommended (insufficient supporting evidence)

For Chronic Pancreatitis (CP):

  • 3.1b & 3.12a. Recommends routine followup every 3-6 months and a regular diet
  • 3.3a, 3.4a, & 3.5a Monitoring: recommends checking fat-soluble vitamin levels every 6 to 12 months, checking for EPI with elastase (or 72 hr fecal fat) every 6-12 months, and BMD (bone mineral density) if CP and malnutrition (especially if Vit D deficiency or hx/o fractures)

My take: This report provides a methodical approach for the care of children with these pancreatic disorders.

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Tide pools and wide beach at Cumberland Island 2018

Global Prevalence of Celiac Disease

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Briefly noted: P Singh et al. Clin Gastroenterol Hepatol 2018; 16: 823-36. After a systemic review which selected 96 articles from a pool of 3843 published between 1991 through 2016, the authors determined a pooled global prevalence of 1.4% in 275,818 individuals based on seroprevalence (positive TTG or EMA).  Biopsy-confirmed celiac disease was noted in 0.7% in 138,792 individuals.

In their study, biopsy-proven disease was most prevalent in Argentina, Egypt, Hungary, Finland, Sweden, New Zealand, and India.

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Serology Titers Associated with Clinical Expression of Ulcerative Colitis in Children

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Briefly noted: A recent study (EA Spencer et al.Inflamm Bowel Dis 2018; 24: 1335-42) examined phenotype and serology in 399 children with newly diagnosed ulcerative colitis (PROTECT study).

Key findings:

  • 65% had positive serology for pANCA; 62% in those <12 and 66% in those ≥12 years
  • 19% had positive serology for anti-CBir1; 32% in those <12 and 14% in those ≥12 years
  • High titer (≥ 100)) pANCA positivity was associated with more extensive disease but not with PUCAI values or Mayo endoscopic subscores.

My take: The serology titers for IBD, in my view, have academic interest but do not routinely enhance patient care.

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Amelia Island

 

Pilot Study: Treating Obstructive Sleep Apnea with Beneficial Effects on Fatty Liver Disease in Children

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Briefly noted: A small pilot study (n=9) (SS Sundaram et al. J Pediatr 2018; 198: 67-75) showed that treatment (with home CPAP) of obstructive sleep apnea (OSA) was associated with improved alanine aminotransferase levels, reduced metabolic syndrome markers and lower F(2)-isoprostanes (a marker of oxidative stress) in pediatric patients with nonalcoholic fatty liver disease (NAFLD). All nine of the participants were Hispanic males with a median age of 11.5 years; they had a median BMI of 29.5 and had biopsy-proven NAFLD. The improvement in NAFLD parameters occurred despite an increase in BMI. The authors note that studies in adults have shown contradictory findings with regard to whether treatment of OSA helps NAFLD.

My take: This study suggests potential beneficial liver effects of treating OSA.  Regardless, treatment of OSA could be considered a quality metric in the care of children with NAFLD as better sleep at night has additional clear benefits.

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Outside Mercedes-Benz Stadium (Atlanta)

Use of Fecal Microbiota Transplantation for Primary Clostridium difficile Infection

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A recent letter (FE Juul et al. NEJM 2018; 378: 2535-6) describes the results of a small study in which fecal microbiota transplantation (FMT) (n=9) was compared with metronidazole (n=11) for primary treatment of Clostridium dificille infection. The primary end point was clinical cure (firm stool consistency ≤3 BMs/day) and no evidence of recurrent C diff infeciton.

Key findings:

  • In C diff group, 5 had full primary response and an additional 3 had full response after additional antibiotics which were added in in three of the four without primary response by day 4. By day 70, 7 of 9 (78%) had full response.
  • In metronidazole group, five had full primary response.  By day 70, only five of eleven (45%) had full response.

My take: It would probably be better to compare FMT to either vancomycin of fidaxomin  (rather than metronidazole) for primary treatment.  Until more data are available, this study does not change clinical practice of using antimicrobials for C diff as primary treatment.

Lessons in Diarrhea (part 2)

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More from the following: JR Thiagarajah et al. Gastroenterology 2018; 154: 2045-59. (Senior authors/corresponding authors: Yaron Avitzur and Martin Martin).  This article provides an excellent review of persistent infantile diarrhea and provides algorithms to help in the evaluation of these disorders.  These algorithms incorporate the role of exome sequencing.

The authors divide infants with watery diarrhea/CODEs into five categories -detailed in their Table 2 which also has OMIM #, inheritance pattern, gene name, protein function:

#1 Epithelial nutrient/electrolyte transport:

  • congenital chloride
  • congenital sodium
  • glucose-galactose malabsorption (GGM)
  • primary bile acid diarrhea
  • acrodermatitis enteropathica

#2 Epithelial enzymes and metabolism

  • Congenital lactase deficiency
  • Sucrase-isomaltase deficiency
  • Trehalase deficiency
  • Enterokinase deficiency
  • DGAT1 deficiency
  • PLVAP deficiency
  • Abetalipoproteinemia
  • Hypobetalipoproteinemia
  • Chylomicron retention disease
  • Dyskeratosis congenita
  • Kabuki syndrome

#3 Epithelial trafficking and polarity

  • Microvillus inclusion disease
  • Tufting enteropathy
  • Syndromic Na diarrhea
  • Trichohepatoenteric syndrome 1 & 2
  • Familial hemophagocytic lymphohistiocytosis 5
  • TTC7A deficiency

#4 Enteroendocrine cell dysfunction

  • Enteric anendocrinosis
  • X-linked lissencephaly and MR
  • Proproteint convertase 1/3 deficiency
  • Mitchell-Riley syndrome

#5 Immune dysregulation-associated enteropathy (partial list)

  • IPEX
  • ICOS deficiency
  • ADAM17 deficiency
  • EGFR deficiency
  • CD55 deficiency
  • CTLA4 deficiency
  • LRBA deficiency
  • XIAP

So, to tackle this long list the authors recommend combining typical clinical evaluation along with early genetic evaluation.

Clinical evaluation of watery diarrhea:

  • Early endoscopic biopsy (EGD/Flex sig) -obtain samples for routine histology and for electron microscopy.  Disaccharidase evaluation can be helpful; though, “these enzymatic assays are often unreliable due to poor sampling or in the setting of inflammation or villus atrophy due to secondary disaccharidase deficiency.”
  • If normal villus/crypt architecture, the next step is determining whether the diarrhea improves with fasting. This could indicate GGM, sucrase-isomaltase, congenital lactase deficiency or enteroendocrine cell loss.  The first three can be elucidated by offering specific dietary challenges using either a feeding trial with carbohydrate-free or fructose-based formula.
  • If normal villus/crypt architecture, and if the diarrhea does not improve with dietary manipulation, consider congenital chloride diarrhea, congenital sodium diarrhea, primary bile acid mediated diarrhea, and hormone-induced diarrhea.
  • If normal villus/crypt architecture, and there is hypoalbuminemia/PLE, consider DGAT1 deficiency, CD55 deficiency, and lymphangiectasia.
  • If abnormal villus/crypt architecture, then this is likely either a postinfectious/autoimmune disorder or due to an epithelial structural defect like tufting enteropathy, microvillus inclusion disease, TTC7A deficiency or SKIV2L defect

When one looks at the magnitude of disorders that could result in CODEs and their potential clinical importance, it is not surprising that the authors state emphatically:

“In cases of a suspected CODE, where the diagnosis based on clinical evaluation is unclear, it is now standard of care to perform whole-exome sequencing to identify a possible causative genetic mutation.”

My take: This article provides a great deal of information in tackling a difficult problem.

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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Little Talbot State Park (near Amelia Island)

Lessons in Diarrhea (part 1)

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One of the most influential medical articles that I’ve read this year: JR Thiagarajah et al. Gastroenterology 2018; 154: 2045-59. (Senior authors/corresponding authors: Yaron Avitzur and Martin Martin).  This article provides an excellent review of the terminology and provides algorithms to help in the evaluation of chronic diarrhea in infants.  These algorithms incorporate the role of exome sequencing.

The first part of this review focuses on terminology:

  • For those with persistent and severe diarrhea that is not due to an acquired short bowel syndrome (eg. from necrotizing enterocolitis, gastroschisis, or volvulus), the authors use the term congenital diarrhea and enteropathies (CODEs).  They suggest using CODEs in place of intractable or protracted diarrhea of infancy.
  • Instead of osmotic diarrhea, the authors prefer diet-induced diarrhea since all diarrhea involves osmotic forces.  Typically, with this type of diarrhea, stool osmotic gap is >100 mOsm.
  • Secretory diarrhea “is also imprecise…We prefer to use the term electrolyte-transport-related diarrhea” (eg. congenital sodium or congenital chloride diarrhea)

Key points:

  • Most acquired diarrhea is related to infectious agents and to allergic disorders. Though, persistent diarrhea after an infection could be an early sign of a primary immunodeficiency.
  • Stool osmotic gap: = 290 – 2 x (Stool Na + Stool K).  Osmotic gap >100 mOsm is high, <50 mOsm is low.
  • Stool osmolality in almost all cases is isomolar to serum (~290).  If there is suspicion of improper collection or tampering, then this can provide objective evidence of this.
  • Reducing substances >0.5% indicates malabsorption of monosaccharides. Low pH (<5.3) is indicative of carbohydrate malabsorption (due to abundance of short-chain fatty acids that are products of fermentation)
  • Elastase is “unchanged by intestinal proteases and if low can imply pancreatic insufficiency.”  Falsely-low values can occur due to dilution in high-volume diarrhea.
  • Alpha-one-antitrypsin is largely resistant to intestinal proteases and elevation indicates excess enteric protein loss (eg. protein-losing enteropathy)

Diagnostic evaluation:

  • See figure 1 in review.  Initial evaluation after exclusion of acquired diarrheas (eg infection/allergic): History, Blood tests (CBC, CMP, CRP, ESR, IgG, lipid panel), Stool tests (electrolytes, reducing substances, elastase, fecal fat, A1AT, pH, calprotectin/lactoferrin).
  • Determining stool output may require a “urine catheter for a few days” for accuracy and help elucidate the effect of fasting on stool output.
  • Figure 2 divides evaluation based on type of diarrhea: watery, fatty, and bloody.
  • Fatty diarrhea may be due to pancreatic insufficiency, abetalipoproteinemia and chylomicron retention disease.  The latter two disorders typically are indicated by fat-laden enterocytes in histologic sections
  • Bloody diarrhea “should precipitate investigation for very-early-onset inflammatory bowel disease, autoimmune enteropathy, or primary immunodeficiency”
  • Watery diarrhea –see tomorrow’s post.  Before undergoing extensive evaluation, the authors recommend obtaining an UGI/SBFT to exclude congenital short bowel syndrome.

My take: after initial exclusion of common causes for diarrhea in infancy, early endoscopy is needed along with early use of genetic testing.

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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Little Talbot State Park