Submucous plexus altered in functional dyspepsia

Last Updated: 2015-06-29

By Will Boggs MD

NEW YORK (Reuters Health) - The submucous plexus shows functional and structural changes in patients with functional dyspepsia, according to duodenal biopsy findings.

"This is a set of patients in which normal pathological assessments do not reveal any abnormalities," Dr. Pieter Vanden Berghe, from the University of Leuven, Belgium, told Reuters Health by email. "Therefore, it is indeed surprising that our results were so telling: using improved microscopic imaging technology and analysis, not only the neuronal signaling, but also the volume of the glial cells and the amount of eosinophils and mast cells were found to be altered."

By definition, functional gastrointestinal disorders are diagnosed in the absence of abnormalities that can explain the patient's symptoms and complaints. Low-grade inflammation is commonly present, but it does not fully justify the magnitude of the clinical symptoms.

Dr. Vanden Berghe's team investigated the function and immune cell infiltration of submucous plexus in duodenal biopsies from 18 newly diagnosed functional dyspepsia patients - 10 with epigastric pain syndrome (EPS) and 8 with postprandial distress syndrome (PDS) - and 20 age- and sex-matched controls.

As expected, the researchers found no macroscopic changes in any of the biopsies.

But only 56% of neurons in functional dyspepsia patients responded to high-K+ depolarization, compared with 76% of controls, and trains of electrical pulses activated only 28% of high-K+ responsive neurons in functional dyspepsia patients, compared with 56% of controls.

Submucous plexi from functional dyspepsia patients had significantly more eosinophils and mast cells in close proximity to neurons than did plexi from controls, according to the June 16 online report in the American Journal of Gastroenterology.

Functional neuronal response amplitudes were inversely related to the number of infiltrating cells.

Neuronal amplitudes did not correlate with symptoms, though, and only in PDS patients did symptoms correlate with the number of eosinophils.

Coauthor Dr. Carla Cirillo, also of the University of Leuven, told Reuters Health by email, "It is still early to talk about clinical implications. We need to enlarge the cohort of patients and to go deeper in finding a (possible and specific) correlation between the clinical symptoms and the cellular findings."

"What is striking is that, indeed, we can confirm that the physician's judgment coincided very well with our measured parameters, especially while up till now no cellular or organic correlate was ever found in this disease," Dr. Vanden Berghe concluded.

Both agreed that close cooperation between clinicians and basic researchers is vital to understanding what's behind functional dyspepsia.

The authors reported no outside funding or disclosures.

SOURCE: http://bit.ly/1LQUAO3

Am J Gastroenterol 2015.