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.