Probe-based confocal laser microscopy identifies criteria predictive of active celiac sprue

Celiac sprue is an underdiagnosed chronic intestinal inflammatory disease. Probe-based confocal laser microscopy (CLM) is a novel endoscopic technique for in vivo inspection of the intestinal mucosa that has not been evaluated in celiac sprue yet.

To develop CLM criteria most predictive of celiac pathology in a prospective pilot study.

Twenty-one patients (male n = 5, f = 16, mean age 52 years) with established or suspected celiac sprue, seven of whom had confirmed active disease (Marsh III) and 14 duodenal normal mucosa. CLM images from 91 duodenal sites were assessed. CLM recordings were obtained next to Argon beamer labeled areas. Biopsies were taken from the same spots for precise histological matching. After establishing histology-correlated criteria on one sample per patient, the remaining CLM recordings from the same patients were randomized and blindly evaluated.

Villous atrophy and irregular appearing villi were most predictive of celiac pathology. Although the presence of crypts was diagnostic for celiac pathology, it was only recognized in 26.7% of celiac pathology sites. Using these criteria in the blinded assessment, the overall endoscopist's prediction of celiac sprue was accurate in 89.8% of all biopsy sites in 85.7% of all patients. Preliminary interobserver agreement testing villous atrophy, irregular villi, and crypts was poor (kappa 0.05 to 0.26).

Probe-based CLM criteria developed in this pilot trial appear promising for the detection of active celiac sprue. Preliminary interobserver variability was high, indicating a learning curve effect. Our criteria need validation in an independent patient population.