ErLangen Endocytoscopy for ColiTis (ELECT) Score Demonstrates Superior Correlation with Histologic Activity Compared to Ulcerative Colitis Endoscopic Index of Severity in Patients with Ulcerative Colitis: A Novel Case Series

To the Editor

Histologic remission has emerged as a more reliable predictor of long-term outcomes in ulcerative colitis (UC) than endoscopic remission alone. While widely used endoscopic indices such as the ulcerative colitis endoscopic index of severity (UCEIS) offer standardized evaluation of mucosal inflammation, they fall short in accurately capturing microscopic disease activity.[1] The recently validated ELECT (ErLangen Endocytoscopy for ColiTis) score offers an opportunity to assess in vivo histologic changes during real-time colonoscopy using contact-based ultra-high magnification endocytoscopy.[2]

In this observational series, we evaluated six patients with clinically stable UC who underwent high-definition colonoscopy (CF-H290ECI; Olympus, Tokyo, Japan) with both standard white light and endocytoscopic imaging (using 0.05% crystal violet and 1% methylene blue). In addition to routine scoring with UCEIS, each patient was evaluated using the ELECT score, which incorporates crypt shape, crypt distance, vascular distortion, inflammatory cell infiltrates, and the presence of crypt abscess.[2] Histologic inflammation was assessed using the Nancy histologic index, with histologic remission defined as a Nancy histologic index ≤1 ([Fig. 1]).

Fig. 1 Representative endoscopic, endocytoscopic, histologic, and correlation images from a patient with ulcerative colitis. (A) Texture and color enhancement imaging (TXI) showing patchy loss of vascular pattern (ulcerative colitis endoscopic index of severity [UCEIS] was scored as 1). (B–E) Sequential endocytoscopy images show preserved crypt architecture (B, C), vascular distortion: tortuous crowded vessels (D), and mild inflammatory infiltrate without any crypt abscess, suggesting an ErLangen Endocytoscopy for ColiTis (ELECT) score of 2. (F–H) Histopathology (F: ×4, G: ×10, H: ×40) reveals mild crypt disarray and mild acute inflammatory infiltrates consistent with histologic activity (Nancy index = 2). (I) Spearman's correlation plots: Left—UCEIS versus Nancy index (r = 0.94, p = 0.005); Right—ELECT score versus Nancy index (r = 0.98, p < 0.001), showing stronger correlation of the ELECT score with histologic inflammation.

Among the six patients (age range: 21–52 years; 33% female), four were in endoscopic remission by UCEIS (score ≤1), and three had an ELECT score ≤2. Histologic remission was achieved in two patients. Interestingly, a patient classified as endoscopically healed by UCEIS had persistent microscopic activity, as indicated by the ELECT score, confirmed by the Nancy index ([Table 1]). The UCEIS score was 0, but ELECT scoring revealed distorted crypts and abnormal vasculature, resulting in an ELECT score of 3 and a Nancy index of 2—indicating histologic inflammation missed by standard endoscopy.

Table 1 Summary of endoscopic subscores, endocytoscopy score, and histology grade in six patients with ulcerative colitis

Patient number	Sex	Age (y)	UCEIS (vascular)	UCEIS (erosions and ulcers)	UCEIS (bleeding)	Total UCEIS score (0–8)	ELECT score (0–6)	Nancy index (0–4)
Patient 1	Female	21.0	1.0	1.0	1.0	3.0	4.0	4.0
Patient 2	Male	34.0	1.0	1.0	0.0	2.0	3.0	3.0
Patient 3	Male	48.0	1.0	0.0	0.0	1.0	2.0	3.0
Patient 4	Female	39.0	0.0	0.0	0.0	0.0	0.0	1.0
Patient 5	Male	52.0	0.0	0.0	0.0	0.0	0.0	0.0
Patient 6	Male	28.0	0.0	0.0	0.0	0.0	3.0	2.0

Abbreviations: ELECT, ErLangen Endocytoscopy for ColiTis; UCEIS, ulcerative colitis endoscopic index of severity.

Statistical correlation using Spearman's rank correlation revealed that the ELECT score showed a very strong and statistically significant correlation with the Nancy index (r = 0.98, p < 0.001). While the UCEIS score also correlated significantly with histology (r = 0.94, p = 0.005), the ELECT score outperformed UCEIS in strength of association and visual alignment on scatter plots. These results suggest that ELECT may offer a more sensitive measure of histologic healing in patients where conventional indices may underreport inflammation, particularly in the absence of bleeding. Given the small sample size (n = 6), we used Spearman's correlation (nonparametric test) as an exploratory tool to assess monotonic associations; however, the results should be interpreted with caution due to limited power and potential for type I error.

Limitations of this study include the small sample size and the observational case series design, which preclude generalizability. Statistical correlations should be considered hypothesis-generating. Additionally, endocytoscopy may be limited by user expertise, limited field of view leading to sampling bias in patchy lesions, subjective nature especially in early learning curve, need for mucosal preparation, variability in dye uptake, semiquantitative nature of the ELECT score, and limited access to advanced imaging platforms. Further validation in larger, prospective cohorts is warranted.

 

MissingLinkText

Practical Implications for Endoscopists

• Endocytoscopy allows for direct visualization of histologic features (e.g., crypt distortion, vascular changes) during the procedure, reducing reliance on random biopsies to document histologic healing.

• ELECT score identifies microscopic abnormalities not visible with UCEIS, particularly in patients without bleeding, addressing limitations of traditional mucosal healing indices.

• ELECT scoring has been associated with the prediction of flares, hospitalizations, and treatment escalation, offering a real-time surrogate for histologic risk stratification.[3]

• The ELECT score incorporates five defined parameters (crypt shape, crypt distance, vascular architecture, inflammatory infiltrate, and crypt abscess) with good interobserver agreement, offering a standardized and reproducible method for real-time assessment of mucosal healing in UC.

• As histologic remission becomes a therapeutic goal in UC, ELECT provides immediate feedback on healing status—enhancing precision in treat-to-target strategies.[4]

• While UCEIS remains valuable for assessing mucosal healing, incorporating ELECT into endoscopic evaluation can add granularity in assessing disease activity, particularly in nonbleeding phenotypes or clinical remission.

 

MissingLinkText

 

MissingLinkText

Conflict of Interest

None declared.

Data Availability Statement

All the data associated with the paper are included in the manuscript. Additional data are available on request to the corresponding author.

Authors' Contributions

P.P. was responsible for concept and design and also prepared the initial draft; D.N.R., M.T., R.G., Z.N., and M.R. provided administrative support; P.P., M.T., A.S., A.K., and T.R. were responsible for provision of study material/patients; K.P. and P.P. were responsible for acquisition of data and also performed data analysis and interpretation; P.P., A.S., A.K., and T.R. performed the procedure; M.T., Z.N., D.N.R., R.G., M.R., A.S., A.K., and T.R. performed the critical revision of the manuscript; M.R., Z.N., M.T., A.S., A.K., T.R., R.G., and D.N.R. provided important intellectual inputs and preformed revision; manuscript writing and approval of final manuscript were done by all the authors.

Ethical Approval

The study was approved by the Institutional Review Board. Written informed consent was taken from each patient, and the study would conform to the 1975 Declaration of Helsinki ethical guidelines.

Patients' Consent

Informed consent was obtained from all individual participants included in the study.

• References

• 1 Irani NR, Wang LM, Collins GS, Keshav S, Travis SPL. Correlation between endoscopic and histological activity in ulcerative colitis using validated indices. J Crohns Colitis 2018; 12 (10) 1151-1157
• 2 Vitali F, Morgenstern N, Eckstein M. et al. Endocytoscopy for assessing histologic inflammation in ulcerative colitis: development and prospective validation of the ELECT (ErLangen Endocytoscopy in ColiTis) score (with videos). Gastrointest Endosc 2023; 97 (01) 100-111.e1
• 3 Park S, Abdi T, Gentry M, Laine L. Histological disease activity as a predictor of clinical relapse among patients with ulcerative colitis: systematic review and meta-analysis. Am J Gastroenterol 2016; 111 (12) 1692-1701
• 4 Turner D, Ricciuto A, Lewis A. et al; International Organization for the Study of IBD. STRIDE-II: an update on the selecting therapeutic targets in inflammatory bowel disease (STRIDE) Initiative of the International Organization for the Study of IBD (IOIBD): determining therapeutic goals for treat-to-target strategies in IBD. Gastroenterology 2021; 160 (05) 1570-1583

Publikationsverlauf

Artikel online veröffentlicht:
08. September 2025