IBD Shorts August 2018

Vitamin D Receptor Signaling in IBD. Inflamm Bowel Dis 2018; 24: 1149-54.  This article reviews the ways vitamin D/vitamin D receptor may contribute to the genetic, environmental, immune, and microbial aspects of IBD.

LY Chi et al. Inflamm Bowel Dis 2018; 24: 1344-51. This study with 223 pediatric patients & young adults found that current or prior combination therapy with infliximab, compared to monotherapy resulted in higher infliximab levels and lower antibody formation. Combination agent was mainly methotrexate (n=71) rather than thiopurine (n=13). In those with infliximab dose <10 mg/kg, those currently receiving combination therapy had median level of 11.1 compared with 7.0 for prior combination and 5.86 for monotherapy (never combination).

CM Johnson et al. Clin Gastroenterol Hepatol 2018; 16: 900-7.  In this retrospective study with 1466 patients with Crohn’s disease, the subset of patients with granulomas (n=187, 12.8%) were associated with a more aggressive phenotype and a younger age at diagnosis (23.6 years compared with 27.9 years; P= .0005). These patients had higher rates of steroid use, narcotic use, more stricturing and penetrating disease along with increase rates of surgery.

 

Time Will Tell: Granulomatous Upper GI Inflammation

A recent retrospective study (K Queliza et al. JPGN 2018; 66: 620-23) describes seven patients with granulomatous disease in the upper GI tract who were diagnosed with ulcerative colitis.

This study examined patients at a single center between 2007-2016 with ages ranging from 2 years to 17 years.  Median time of followup is not provided.  Two patients required colectomy.  All patients had non-casseating granulomas identified in either the stomach or duodenum (or both) along with moderate to severe pancolitis.  All of the patients had extensive investigations, generally cross-sectional imaging (MRE or CT) or capsule endoscopy

Key point::

  • “The final classification of IBD was based on expert opinion from gastroenterologists, radiologists, and pathologists upon thorough review of the medical records.”

My take: This study highlights the confusion of the essentially binary classification of IBD into either Crohn’s disease or ulcerative colitis, when in fact there are hundreds of genetic mutations which give rise to inflammatory bowel disease.  Given that granulomas are a hallmark of Crohn’s disease and there are no pathognomic features of ulcerative colitis, only time will tell if these patients have an ulcerative colitis phenotype.  I wonder how many centers would take exception to this classification and describe these patients as ‘indeterminate’ colitis/IBDU (IBD unclassified).

Related blog posts:

Upper endoscopy useful for identifying Crohn’s disease

In a large pediatric study, the value of upper endoscopy in detecting Crohn’s disease (CD) is evident (JPGN 2012: 54: 753-57).

While the majority of pediatric patients with suspected inflammatory bowel disease probably undergo both upper endoscopy and colonoscopy, the added value of upper endoscopy remains unclear.  In this retrospective study with 171 pediatric patients (70 with CD, 33 with UC, 68 Non-IBD), 11% of children with CD had the diagnosis established based “solely” on the finding of granulomatous inflammation in upper intestinal tract (along with clinical symptoms).

Other key findings:

  • Presence of histologic gastric inflammation in CD patients compared to control patients was significantly higher (p<0.0001) but not significantly higher compared to UC patients (p=0.19).
  • Duodenal inflammation was highly suggestive of CD compared with both UC and non-IBD patients.  This occurred in 19% of CD patients compared with 0% and 1% in the other groups respectively.
  • 21 children (30%) had granulomas identified in upper GI tract (19 in stomach).  In 8 (11%), the diagnosis was changed based on this finding.  Prior to histology, the tenative diagnosis: 2 UC, 4 IC, 2 non-IBD.
One curious finding was a the presence of “perianal abscess/fistula” with similar frequency in CD patients and UC patients based on their Table 2 Patient Characteristics.
Additional references:
  • -IBD 2009; 15: 1101-4.  Presence of UGI disease in IBD.
  • -JPGN 2007; 44: 653.  NASPGHAN report on discriminating/labelling UC vs. Crohn’s.
  • -JPGN 2002; 35: 636-40. Advocates panendoscopy for all new IBD.  Granulomas in 28% of EGDs & 71% of UC pts c some abnl on EGD; 82% Crohn’s c abnl EGD.
  • -JPGN 2005; 41: abstract 181 (page 549).  UGI identified granulomas in 15% that were not identified elsewhere.
  • -JPGN 2004; 39: 257-61. Diagnostic role of EGD for pediatric IBD.
  • Magnetic resonance enterography for Crohn’s disease