Histomorphological Spectrum of Duodenal Pathology in Functional Dyspepsia Patients

Degranulated Eosinophils Contain More Fine Nerve Fibers in the Duodenal Mucosa of Patients With Functional Dyspepsia

Background/Aims

Functional dyspepsia (FD) is characterized as chronic recurrent upper gastrointestinal symptoms in the absence of any organic disorder. We hypothesized that duodenal low-grade inflammation activates superficial afferent nerve sprouting, thereby contributing to hypersensitivity in patients with FD.

Methods

A prospective case-control study was conducted in a tertiary referral center. FD was defined using the Rome III criteria. Standardized endoscopic biopsies were performed in the stomach and duodenum. Hematoxylin and eosin staining and immunohistochemical staining for major basic proteins were performed to detect granulated eosinophil-derived granules, and S-100 staining was performed to detect fine nerve fibers.

Results

A total of 51 patients with FD (82% female; mean age 35.8 ± 13.4 years) and 35 controls were enrolled. Activated eosinophil counts in the duodenum were significantly higher in patients with FD than in controls (41.4% vs 17.1%, P = 0.005). Microscopic duodenitis was more frequently detected in patients with FD than in controls. Fine nerve fibers were more abundant in patients with FD than in controls (45.1% vs 11.4%, P = 0.029). The abundance of fine nerve fibers highly correlated with the degree of activated eosinophils.

Conclusion

Duodenal low-grade inflammation, such as mucosal eosinophilic accumulation with degranulation, promoted mucosal enteric nerve fiber density and sprouting in patients with FD.

Duodenal Pathology in Patients with Rumination Syndrome: Duodenal Eosinophilia and Increased Intraepithelial Lymphocytes

BACKGROUND

Rumination syndrome is a functional gastrointestinal disorder characterized by effortless, postprandial regurgitation. Duodenal eosinophilia has been described in patients with functional dyspepsia. Because of the significant symptomatic overlap between functional dyspepsia and rumination syndrome, we hypothesized that histological changes might exist among patients with rumination syndrome.

METHODS

We included patients with rumination syndrome in whom we had obtained duodenal biopsies and compared these with controls. Digital images of biopsy specimens were analyzed for routine pathology and eosinophil counts by a pathologist blinded to the case-control status.

RESULTS

The 22 patients with rumination syndrome had a mean age of 39.2 years (range 21-71) and 77% were female. The 10 controls had a mean age of 34.3 (range 27-69) and 80% were female. There was a significant increase in the mean eosinophil count among the patients with rumination syndrome compared to controls, 26 per mm² (range 16-42) versus 18 per mm² (range 10-28), p = 0.006. Intraepithelial lymphocyte counts were significantly higher in rumination patients (mean 15/100 enterocytes, range 8-29) versus controls (mean 11/100 enterocytes, range 11-18), p = 0.02.

CONCLUSION

Patients with rumination syndrome have subtle duodenal pathology with eosinophilia and increased intraepithelial lymphocyte counts compared to controls.