IBD Reviews: Role of Antibiotics and Data on Biomarkers

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A clinical review, “Antibiotics in IBD: Still a Role in the Biological Era?” (O Ledder, D Turner, Inflamm Bowel Dis 2018; 24: 1676-88).  While this article provides a detailed review of the use of antibiotics for Crohn’s (including perianal disease), Ulcerative colitis and the effects on the microbiome, the potential use for very early onset (VEO) IBD caught my attention:

“We have recently begun considering oral vancomycin and gentamicin as sole firstline therapy in the rare form of infantile (ie <2 years of age) mild to moderate IBD, with promising success…this is merely investigational” at this time.  (Ref: Lev-Tzion R et al. Digestion 2017; 95: 310-13).

My take: Antibiotics can be a helpful adjunct therapy in both Crohn’s disease and Ulcerative colitis. It is unclear what role antibiotics will have for VEO-IBD.

A recent commentary (R Khanna et al, Inflamm Bowel Dis 2018; 24: 1619-23) examines the role of biomarkers.  While much of this topic has been reviewed extensively, I found the part about calprotectin helpful.  One of the topics with discrepant data has been the negative predictive value of calprotectin for detecting inflammatory bowel disease.  The data in this review:

  • From a meta-analysis in patients with symptomatic ulcerative colitis, calprotectin had a sensitivity of 0.88 and specificity of 0.79 compared to endoscopic inflammation.  For Crohn’s disease, the respective values were 0.87 and 0.67.
  • For histologic remission in ulcerative colitis, a study found that with a threshold of 155 mcg/g, calprotectin had a sensitivity of 78% and specificity of 71%.
  • Another study suggested that values <100 mcg/g indicate quiescent disease, values 100-250 suggest possible active inflammation, and values >250 mcg/g suggest active inflammation.
  • A cross-sectional study indicated that calprotectin ≥57  mcg/g had a sensitivity of 91% and specificity of 90% to identify endoscopically-active disease (Gastroenterol 2016; 150: 96-102)

My take: Sensitivity/specificity vary greatly based on the likelihood of disease; in populations at lower risk for IBD, a calprotectin has a high level of excluding active inflammation/IBD. In populations with IBD, levels more than 250 mcg/g indicate a high likelihood of active inflammation whereas levels between 100-250 are indeterminate.

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