Predicting Endoscopic Remission Using Simple Blood Tests in Crohn’s Disease Patients on Anti-TNFs

Aims Endoscopy is the gold standard for assessing disease severity in Crohn's disease, although it is an invasive procedure. Biological markers have been routinely used as a non-invasive means of determining disease activity. The aim of this study was to determine the correlation between common biological markers and endoscopic activity in Crohn's disease.

Methods This was retrospective, descriptive, and analytical study conducted in a gastroenterology department over a 20-year period (2004–2024) including patients with Crohn's disease under antiTNF who underwent a coloscopy. We compared patients with endoscopic disease activity, with those in endoscopic disease remission. We analyzed the correlation between the CDEIS score and biological markers using Spearman's coefficient. Association between biological blood tests and endoscopic activity was analyzed using logistic regression.

Results Out of a total of 1,200 patients monitored for Crohn's disease, 20.3%(244) were on anti-TNF (Adalimumab or Infliximab). The average age at diagnosis was 33.5+/-14.3 years. Sex ratio M/F was 1,3. Tobacco use was present in 16.9%(40). Ileocolonic location L3 represented half of our series 49.6%(120). The inflammatory phenotype was the most observed, with a rate of 46.7%(113).45.9%(111) of the patients had a history of perianal disease.Regarding biological parameters, hemoglobin≤10 g/dL was observed in 35.3%(48) of the cases; a white blood cell count>5,400/µL in 82%(109); a platelet count>150,000/µL in 97.7% (125) of patients; a CRP value greater than 6 in 81.3%(117); and an albumin level>30 g/L in 71.7%(91) of cases. A platelet-to-white blood cell ratio(PLT/WBC) greater than 30 was found in 78.5%(102). Additionally, 41.5%(35) had a platelet-to-albumin ratio>10,000, and 32.4%(45) had a CRP/albumin ratio>1.18. 89.1%(155) of patients showed signs of endoscopic activity of the disease. We identified 155(89.1%) patients who presented endoscopic disease activity. Compared with those in endoscopic disease remission, patients suffering from a flare exhibited significant differences only in the following indices: CRP, CRP/ALB, and PLQ/WBC, with a CRP greater than 6 in 84.7% (83/98) of the cases (p=0.01), a rate of 62% (64/102) with a CRP/ALB ratio lower than 1.18 (p=0.04), while 80.5% (66/82) had a PLT/WBC ratio greater than 30 (p=0.03). No difference was found between the two groups concerning hemoglobin levels, albumin levels, and the PLQ/ALB ratio. Furthermore, the Spearman’s rank correlation coefficient for endoscopic disease activity and C-reactive protein value was 0.199 (95%CI[0.017–0.368],p=0.032).In univariate and multivariate analysis, a CRP>6 as well as a PLQ/GB ratio were associated with endoscopic activity, with respectively; (OR=4.48, 95%CI[1.009-19.965], p=0.04) and (OR=4.95, 95% CI[1.17-21.001],p=0.03).

Conclusions Serological biomarkers, such as CRP and the PLQ/WBC ratio, have shown associations with endoscopic activity in Crohn's disease, suggesting their role in indicating disease activity. Despite these results, endoscopy remains the gold standard for assessing disease activity and guiding therapeutic decisions, as it provides more reliable and direct visual evidence.

Publication History

Article published online:
27 March 2025