A newly developed scoring system, ErLangen Endocytoscopy in ColiTis (ELECT), was found to better predict clinical outcomes among patients with ulcerative colitis (UC) in endoscopic remission compared with other instruments. These findings were published in Gastrointestinal Endoscopy.
The prospective study was conducted between 2019 and 2021 at the University Hospital of Erlangen in Germany, in which patients with established UC who were referred for colonoscopy to evaluate endoscopic disease activity were recruited. In the first phase, the ELECT instrument was formulated for the purpose of grading inflammatory activity using 9750 endocytoscopy images and paired biopsy samples. The ELECT system was then validated among a subset of 46 patients.
The final ELECT score was calculated using 5 parameters: crypt shape, crypt distance, crypt abscess, vasculature architecture, and inflammatory cell infiltrates. In general, normal-appearing features for each parameter are awarded 0 points and abnormal features are awarded 1 point, with the exception of crypt shape findings. For crypt shape, irregular shaped or distorted crypts are awarded 1 point and disruption or loss of crypts are awarded 2 points.
The validation cohort included patients with a mean age of 40.7±16.6 years, the male:female ratio was 22:24, BMI was 24.8±3.7 kg/m2, the average disease duration was 8.4±5.8 years, 19.6% had extraintestinal manifestations, and 56.5% had failure to at least one biological therapy.
Overall, ELECT outcomes were correlated with Mayo Endoscopy Score (MES; r, 0.61; P =.02), Ulcerative Colitis Endoscopic Index of Severity (UCEIS; r, 0.66; P <.05), Robarts Histology Index (RHI; r, 0.829; P <.001), and Nancy Histology Index (NHI; r, 0.829; P <.001) outcomes.
The ELECT instrument during endocytoscopy had an accuracy of 91.3%, sensitivity of 88%, specificity of 95.2%, positive predictive value (PPV) of 95.7%, and negative predictive value (NPV) of 87% for predicting histologic inflammation in UC. These values outperformed the diagnostic performance of the MES (accuracy, 80.4%; sensitivity, 72%; specificity; 90.5%; PPV, 90%; NPV, 73.1%) and UCEIS (accuracy, 82.6%; sensitivity, 76%; specificity; 90.5%; PPV, 90.5%; NPV, 76%) instruments during white light endoscopy.
A total of 5 patients had disease relapse, 2 underwent inflammatory bowel disease-related surgery, and 9 required treatment escalation.
The performance of the ELECT instrument for predicting major adverse outcomes had an accuracy of 67.7%, sensitivity of 57.1%, specificity of 76.5%, PPV of 66.7%, and NPV of 68.4% compared with MES (accuracy, 61.3%; sensitivity, 33.3%; specificity; 87.5%; PPV, 71.4%; NPV, 58.3%), UCEIS (accuracy, 64.5%; sensitivity, 40%; specificity; 87.5%; PPV, 75%; NPV, 60.9%), and RHI and NHI (accuracy, 71%; sensitivity, 60%; specificity; 81.3%; PPV, 75%; NPV, 68.4%).
The performance of the ELECT system may have been affected, as all colonoscopies and endocytoscopies were performed by a single, experienced endoscopist.
“Our results show that our newly developed and validated endocytoscopy score can accurately assess histologic inflammation in UC patients…” the study authors noted. “Furthermore, endocytoscopic grading of microscopic inflammation correlates to long term disease behavior, rendering the possibility that endocytoscopy could be used as a predictive marker for tailoring therapy according to the risk of complicated disease behavior.”
Vitali F, Morgenstern N, Eckstein M, et al. Endocytoscopy for assessing histologic inflammation in ulcerative colitis: development and prospective validation of the ELECT score (ErLangen Endocytoscopy in ColiTis). Gastrointest Endosc. Published online September 1, 2022. doi:10.1016/j.gie.2022.08.023