A recent study (G D’Haens, O Kelly, R Battat et al. Gastroenterol 2020; 158: 515-26,editorial 463) describes the development and validation of a blood test panel to assess Crohn’s disease (CD) endoscopic activity level. The authors evaluated a blood test which measured 13 proteins in the blood using samples from 278 patients. Then there were two validation cohorts:
- 116 biologic-naive CD patients -cohort 1
- 195 biologic-exposed CD patients -cohort 2
The blood tests were used to develop an endoscopic healing index (EHI) score (0-100). Higher scores indicate greater disease activity.
- EHI values below 20 identified remission with a sensitivity of 97.1% and 83.2% in cohorts 1 & 2 respectively; specificity was 69% and 37% respectively.
- EHI values below 50 points identified patients with highest specificity of 100% and 88% in cohorts 1 and 2 respectively.
- EHI AUROC (area under the receiver operating characteristic curve) did not differ significantly from that of fecal calprotectin and were higher than measurement of serum CRP (in cohort 1 but not cohort 2).
The editorial notes that the EHI performed much better in younger, biologically-naive patients and that the EHI could potentially be incorporated into a treat-to-target strategy which would potentially entail followup endoscopy in those with EHI >50.
My take: While the stool calprotectin has some logistical barriers in many patients, the EHI is likely a much more expensive test and needs further validation. For now, the combination of CRP and calprotectin are the best noninvasive biomarkers to assess CD activity.
Briefly noted: Vedolizumab-Induced Pulmonary Toxicity -Case report of a patient with ulcerative colitis who developed interstitial lung disease (Gastroenterol 2020; 158: 478-9).
Related blog posts:
- What is the Calprotectin Threshold for Crohn’s Disease Progression?
- An Insurance Company Doing the Right Thing (with Calprotectin)
- Keep the Stool Cool for More Reliable Calprotectin Testing
- Calprotectin in Triaging Potential Pediatric IBD Cases
- Biomarkers identify patients who benefit and how
- Fecal Calprotectin Monitoring for IBD Relapse
- Best Fecal Marker for Crohn’s Disease: Calprotectin | gutsandgrowth
- Value of Calprotectin | gutsandgrowth
- Prospective Monitoring of Calprotectin for Crohn’s Disease …
- What Treat-to-Target Could Look Like in Crohn’s Disease
- Treating to Target | gutsandgrowth