Published online Apr 28, 2015. doi: 10.3748/wjg.v21.i16.5002
Peer-review started: October 4, 2014
First decision: October 29, 2014
Revised: November 7, 2014
Accepted: January 8, 2015
Article in press: January 8, 2015
Published online: April 28, 2015
AIM: To study the ability of endocytoscopy to identify normal gastric mucosa and to exclude Helicobacter pylori (H. pylori) infection.
METHODS: Endocytoscopic examination of the gastric corpus and antrum was performed in 70 consecutive patients. Target biopsy specimens were also obtained from the assessed region and multiple H. pylori tests were performed. The normal endocytoscopy patterns of the corpus and antrum were divided into the normal pit-dominant type (n-Pit) or the normal papilla-dominant type (n-Pap), respectively characterized as either regular pits with capillary networks or round, smooth papillary structures with spiral capillaries. On the other hand, normal mucosa was defined as mucosa not demonstrating histological abnormalities, including inflammation and atrophy.
RESULTS: The sensitivity and specificity of n-Pit for normal mucosa in the gastric corpus were 94.4% and 97.1%, respectively, whereas those of n-Pap for normal mucosa in the antrum were 92.0% and 86.7%, respectively. The positive predictive values of n-Pit and n-Pap for H. pylori-negative tissue were 88.6% and 93.1%, respectively, and their negative predictive values for H. pylori-negative tissues were 42.9% and 41.5%, respectively. The inter-observer agreement for determining n-Pit and n-Pap for normal mucosa were 0.857 and 0.769, respectively, which is considered reliable.
CONCLUSION: N-Pit and n-Pap, seen using EC, are considered useful predictors of normal mucosa and the absence of H. pylori infection.
Core tip: The identification of minute inflammatory or atrophic changes is very difficult using conventional endoscopy. This is because these changes are usually predicted using non-specific endoscopic findings, such as superficial color, edema and erosions. However, endocytoscopy enables real-time histology, which corresponds well with conventional histopathology. The procedure is also simple (the endocytoscope only has to make contact with the gastric wall) and is therefore expected to be used regularly globally in the future.