Helicobacter pylori Infection Increases Frequency of PDCA-1(+) (CD317(+)) B-cell Subsets.

BACKGROUND AND AIMS: As a newly discovered B-cell subset, PDCA-1(+) B cells have been shown to participate in the immune clearance of invading pathogens. The prominence of PDCA-1(+) B cell immunity in the pathogenesis of Helicobacter pylori infection prompted us to explore the potential role of this subset in gastric H. pylori infection.

METHODS: H. pylori infection was determined by (14)C-urea breath test and Western blot. The frequency of the different sub-compartments of PDCA-1(+) B cells and their relation to serum cytokines was determined in 33 H. pylori-infected and 14 uninfected patients and in 12 healthy controls (HC).

RESULTS: In comparison to uninfected individuals, there was a significantly increased frequency of PDCA-1(+) B cells, PDCA-1(+)IgM(+) B cells, CD93(+)PDCA-1(+) B cells, CD93(+)PDCA-1(+)IgM(+) B cells, CD137(+)PDCA-1(+) B cells and CD137(+)PDCA-1(+)IgM(+) B cells were detected in patients with H. pylori infection, corresponding to increased levels of serum IFN-α and IgM in this group. Compared with H. pylori-positive (HP(+)) chronic non-atrophic gastritis patients, a larger proportion of PDCA-1(+) B cells, CD93(+)PDCA-1(+) B cells and CD137(+)PDCA-1(+) B cells were observed in HP(+) patients suffering from atrophic gastritis or HP(+) peptic ulcers.

CONCLUSIONS: The frequency of the PDCA-1(+) B cell compartment is increased during H. pylori infection. Our data support the potential role of this B-cell subset in the pathogenesis of H. pylori-dependent gastritis.