Diagnostic Accuracy of Blue Light Imaging (BLI) in Detecting Helicobacter pylori Infection Based on Gastric Mucosal Atrophic Patterns – A Retrospective Study

Aims Helicobacter pylori (Hp) infection is an established oncogenic factor, and its eradication is essential for alleviating dyspeptic symptoms and reducing the risk of gastric cancer. Increasing evidence supports digital chromoendoscopy for Hp detection, with recent studies correlating specific gastric mucosal atrophy patterns to Hp status using Blue Light Imaging (BLI). These patterns include the Spotty Pattern (SP) associated with active Hp infection, the Cracked Pattern (CP) observed post-eradication, and the Mottled Pattern (MP) linked to advanced atrophy and intestinal metaplasia [1] [2].

This study aims to assess the diagnostic accuracy of BLI in predicting Hp infection status in a patient sample.

Methods BLI images from endoscopies conducted in a previous study [3] (November 2023 – March 2024) were retrospectively evaluated by one group composed by three expert endoscopists (≥ 10 years’ experience) and other group composed by seven residents, all blinded to Hp status. Findings were classified as no atrophic changes or unspecific pattern in uncertain cases (NA), SP, CP, or MP. A final classification was assigned per photograph based on a≥50% consensus for each group, then compared to histological findings. Finally, concordance analysis was conducted. Statistical analysis was performed using SPSS Statistics 26.

Results A total of 170 images were assessed from a population with a mean age of 59.9±1.1 years, including 98 females (57.6%). Experts classified 100 images (58.8%) as NA, 7 (4.1%) as SP, 44 (25.9%) as CP, and 17 (10.0%) as MP, with no consensus in 2 cases (1.2%). SP was associated with active Hp infection (OR 6.5; 95% CI [1.1-36.6]; p=0.04), while CP was inversely related (OR 0.17; 95% CI [0.03-0.98]; p=0.047). MP was more frequent in older patients (63.1±2.2 years), though age differences were not statistically significant [SP: 52.9±6.1, p=0.057; CP: 59.8±2.5, p=0.31], and was associated with intestinal metaplasia (OR 17.5; 95% CI [4.5-67.5]; p<0.001). In the group of residents, a higher rate of no consensus was seen, although the results in predicting Hp infection were similar. Strong concordance between both groups was observed for images with consensus patterns (kappa=0.85; p<0.001).

Conclusions This study suggests that BLI is a potential reliable, non-invasive method for predicting Hp infection status based on gastric mucosal atrophy patterns. High concordance rates between experienced and less experienced endoscopists indicate BLI’s ease of interpretation and applicability across different skill levels. However, given its retrospective nature, limited number of experts and the use of some lower-quality images, a prospective study is recommended to further validate BLI’s role in accurately predicting Hp infection status.

Publication History

Article published online:
27 March 2025

• References

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