#NASPGHAN19 Postgraduate Course (Part 5)

Here are some selected slides and notes from this year’s NASPGHAN’s postrgraduate course.  There may be errors in omission or transcription on my part.

Link to the full NASPGHAN PG Syllabus 2019 (Borrowed with permission)

– Intestinal Inflammation Session

192 David T. Rubin, MD, University of Chicago Positioning the new IBD therapies: Merging experience with evidence

Some key points:

  • Ustekinumab escalation can increase response. Optimization in CD patients with loss of response led to recapture of response in 69% of patients
  • Tofacitinib –given black warning, will likely be used in more refractory patients
  • May be able retry a previous therapy (Chicago protocol in slide below)

As an aside, while Dr. Rubin is an excellent speaker, my view is that there are so many terrific pediatric IBD specialists, I would favor having a pediatric IBD specialist give this talk at our postgraduate course.  (Some might argue that adult IBD specialists would have more experience with emerging therapies.)

204 Anne Griffiths, MD, FRCPC, Hospital for Sick Children Immunosuppressive therapy in IBD: Can we de-escalate therapy?

  • High rate of relapse when biologic therapy is stopped.  Use of an immunomodulator may reduce the relapse rate when stopping an anti-TNF agent

215 Stacy Kahn, MD, Boston Children’s Hospital When it is not IBD … rare forms of intestinal inflammation

  • For patients with milder microscopic colitis, antidiarrheal agents can be given.  For more severe disease, budesonide is effective.

223 Edaire Cheng, MD, UT Southwestern Medical Center  Eosinophilic inflammation beyond the esophagus

 

Disclaimer: NASPGHAN/gutsandgrowth assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. The discussion, views, and recommendations as to medical procedures, choice of drugs and drug dosages herein are the sole responsibility of the authors. Because of rapid advances in the medical sciences, the Society cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure. Some of the slides reproduced in this syllabus contain animation in the power point version. This cannot be seen in the printed version.

How Many Eosinophils Indicate Eosinophilic Gastroenteritis or Colitis?

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.

Related blog posts:

Gibbs Gardens

Eosinophilic Disease in Children with Intestinal Failure

Last week, this blog posted an abstract regarding the use of “real foods” for short gut kids.  This post looks into whether certain foods may provoke an allergic response.

A large (n=105) single center retrospective study (C Duggan et al. JPGN 2016; 63: 336-39) examined the histology from 208 endoscopic procedures to determine the frequency of eosinophilic disease in children with intestinal failure.

Key findings:

  • 37% of patients had evidence of eosinophilic inflammation in at least one section of the GI tract.
  • Most common sites for eosinophilic disease: colon/rectosigmoid 18/68 (26%), esophagus 17/83 (20%), ileum 9/54 (17%) and duodenum 4/83 (5%)
  • Both peripheral eosinophilia and hematochezia correlated with eosinophilic colitis
  • The authors state that “a strict elemental diet for 3 months before endoscopy was not associated with a decreased frequency of eosinophilic inflammation.”

While a strict elemental diet was not shown to be effective in this study, the limitations of the study design (eg. retrospective, small number on amino acid diet) preclude a definitive answer about the utility of these diets.  Other confounders, including ongoing parenteral nutrition support, also ‘muddy’ the picture.  A prospective study would be able to determine more conclusively how effective elemental diets are at minimizing eosinophilic inflammation and to allow for a more uniform definition of abnormal tissue eosinophilia.

Given the frequency of elemental diets early in life along with prior GI insults, the propensity to eosinophilic disease may have its origins well before this study period.  In healthy children, the LEAP, LEAP-ON, and EAT studies indicated that earlier exposure to allergens reduces the risk of allergic disease.

My take: This study shows a high prevalence of GI eosinophilic inflammation among children with intestinal failure.  Thus, in children with hematochezia and intestinal failure, eosinophilic colitis needs to be considered.

Related blog posts:

Grinnell Glacier, Glacier Natl Park

Glacier Natl Park

Epidemiology of Eosinophilic Disorders

Jensen et al. JPGN 2016; 62: 36-42.  The researchers used a large database (>75 million individuals) representative of US commercially-insured population to provide estimates of the prevalence of several eosinophilic disorders:

  • Eosinophilic gastritis 6.3 per 100,000
  • Eosinophilic gastroenteritis 8.4 per 100,000
  • Eosinophilic colitis 3.3 per 100,000

In the associated commentary by Furuta et al (pg 1), clinicians are encouraged to urge patients with EGID to register on the Consortium for Eosinophilic Gastrointestinal Disease Research registry: https://www.rarediseasesnetwork.org/cms/CEGIR

Related blog posts:

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NASPGHAN Postgraduate Course 2014 -Intestinal Inflammation

This blog entry has abbreviated/summarized the presentations. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well.

Link: PG Course Syllabus – FINAL (entire syllabus)

The speakers reviewed a lot of IBD material (both at the postgraduate course and at the meeting); much of it has been has been covered in previous blog posts:

Early Onset Inflammatory Bowel Disease –Scott Snapper (Boston Children’s Hospital) pg 170 in Syllabus

  • If one has a 1st degree relative with Crohn’s disease: 26-fold increased risk for IBD compared with 8-fold increased risk if 1st degree relative has ulcerative colitis
  • 30% of children have one or more family members with IBD
  • Concordance rate much greater in monozygotic vs dizygotic twins: 10-15% in UC and 25-30% in Crohn’s with monozygotic

Infantile IBD (age <2 years)

  • Often isolated colonic disease
  • Severe course – refractory to multiple immunosuppressant medications, often requiring surgery, occasionally fatal
  • > 40 % with one or more family members with IBD
  • 25% with infantile IBD have this as their first manifestation of underlying immunodeficiency (pg 174): IPEX, CGD, NEMO, Wiscott-Aldrich, XIAP, common variable immunodeficiency
  • NEOPICS: interNational Early Onset Pediatric IBD Cohort Study. Expanded to 80 Centers (250 scientists) on 5 continents with access to over 1000 VEO-IBD patients
  • IL10 Receptor defect results in infantile onset IBD. Hematopoietic stem cell therapy can be curative. Increased risk of B-cell lymphomas.
  • NCF2 variant (NADPH Oxidase Gene) found in 4% of   (n=11/268)
  • TTC7A mutations (identified by whole exome sequencing) cause apoptotic enterocolitis, intestinal atresias, and SCID (severe combined immunodeficiency) –may not benefit by stem cell transplantation
  • Immune workup for VEO-IBD: immunoglobulins, DHR for CGD, lymphocyte subsets. If negative, further genetic testing (candidate gene testing &/or exome sequencing)

Surgery in Crohn’s Disease –Jason Frischer (Cincinnati Children’s)

  • 28% of CD patients need surgery within 10 years of CD diagnosis; 5.7% within one year.
  • Reviewed principles: conserve bowel, reserved for complications/does not cure Crohn’s disease, strictures can be treated without resection.

Perioperative care

  • Preop-“no answer with regard to biologics,” steroids are detrimental (goal <20 mg of prednisone).  Biologics may increase risk of infections (could be related to specific level) but this is unclear.
  • Postop: thromboprophylaxis

Surgical problems (JPGN 2013; 57: 394 NASPGHAN Guidelines): Abscess, Fistula, Stricture

  • Abscess: percutaneously drain abscess if >2 cm and can remove drain when having less than 10 mL/day. Surgery reserved if refractory to conservative treatment –?timing
  • Strictures: steroids to minimize acute inflammation.  Stricturolplasty rare in pediatrics –used only in those without fistulas. Most common stricturolplasty: Heineke-Mikulicz.
  • In Crohn’s patients at Cincinnati children’s who have undergone ileostomy, long-term only 46% able to have intestinal continuity

Crohn’s and UC What to do when antiTNF isn’t working? –Athos Bousvaros (Boston Children’s) pg 190 in Syllabus

Off-label IBD drugs in children for medically-refractory disease.

Potential Rescue treatments

  •  Calcineurin inhibitors for UC (eg. tacrolimus, cyclosporine)
  •  Thalidomide for Crohn disease
  •  Natalizumab for Crohn disease –>not being used anymore. PML risk
  •  Vedolizumab for Crohn disease and UC
  •  Ustekinumab for Crohn disease
  •  Tofacitinib for UC

Before off-label drugs:

  • Optimize TNF: Make sure the diagnosis is right (eg. exclude CGD), Minimize risk of loss of response (combination therapy, optimize dose, scheduled infusions)
  • Consider surgery -strictures, ulcerative colitis, limited disease

Data for tacrolimus from Boston. n=46. (Watson et al, IBD Journal 2011).  Used most frequently with severe UC.

Data for thalidomide –31 of 49 achieved remission. Lazzerini et al, JAMA. 2013;310(20):2164‐2173.  Side effects -birth defects, neuropathy.  STEPS program.

Data for vedolizumab. Feagan et al NEJM 2013; 369:699.  Remission (in the responders) for ulcerative colitis at 52 weeks:

  • 45% of patients getting vedolizumab monthly
  • 42% of patients getting it every other month
  • 16% of patients randomized to placebo

For Crohns’ disease , Vedolizumab also works in Crohn’s disease, but it takes time (Sands et al: Gastroenterology 2014 147:618‐627)

Off-label does not equate to experimental! pg 199:

FDA Statement: The FD&C Act does not, however, limit the manner in which a physician may use an approved drug. Once a product has been approved for marketing, a physician may prescribe it for uses or in treatment regimens or patient populations that are not included in approved labeling. Such “unapproved” or, more precisely, “unlabeled” uses may be appropriate and rational in certain circumstances, and may, in fact, reflect approaches to drug therapy that have been extensively reported in medical literature.

 

“Luminitis:” When Inflammation is Not IBD (Microscopic Colitides) –Robbyn Sockolow (Weill Cornell Medical School) pg 180 in Syllabus

Microscopic Colitis -pediatric prevalence unknown (JPGN 2013;57:557-561). Nonbloody diarrhea with normal-appearance grossly.

  • Lymphocytic Colitis (>20 intraepithelial lymphocytes/100 colonocytes) -Normal crypt architecture
  • Collagenous Colitis -Thick layer (up to 30 micrometers) of collagen in the tissue and increased lymphocytes in colon

Eosinophilic colitis

  • At-risk groups?  Infants & post-transplant patients (tacrolimus trigger?) (Saeed et al Pediatr Transplantation 2006: 10: 730–735)
  • Associated with food allergy, IBD, autoimmune diseases
  • Elevated serum IgE.