Association between helicobacter pylori infection and chronic idiopathic neutropenia.

The possible association between Helicobacter pylori (H. pylori) infection and chronic idiopathic neutropenia (CIN) was investigated. A total of 78 subjects with CIN were recruited in this case-control study. As a control group, 40 subjects without CIN were selected for comparison with the case group. All participants were evaluated for the prevalence of H. pylori infection by 14C-urea breath test. The corrected splenic index (CSI) was calculated, and serum IL-6, IL-8, IL-10 and HsCRP levels were measured. The differences in CSI, serum IL-6, IL-8, IL-10 and HsCRP levels were compared between CIN patients and controls, as well as between subjects with and without H. pylori infection. The positive rate of H. pylori was 87.18% in CIN group and 52.50% in control group, showing a significant difference (Fisher's exact, P=0.000). CSI values, and serum IL-6 and HsCRP levels in H. pylori positive-CIN patients were significantly higher than those in negative subjects (Mann-whitney U-test, P=0.016, P=0.001 and P=0.000 respectively), while IL-10 level declined significantly in H. pylori negative-CIN patients (Mann-whitney U-test, P=0.000). In control group, serum IL-6 and HsCRP levels in H. pylori positive individuals were also increased significantly (Mann-whitney U-test, P=0.000), while IL-10 level declined (Mann-whitney U-test, P=0.018). Multivariate regression analysis revealed that H. pylori infection and IL-10 were significant risk factors for CIN with odds ratio (OR): 3.09, 95.0% CI: 1.22-6.93; P=0.019, and OR: 0.17, 95.0% CI: 0.05-0.94; P=0.021, respectively. This prospective study confirmed the existence of an association between H. pylori infection and CIN, suggesting the screening for H. pylori infection and eradicating bacterium in positive cases seem appropriate and beneficial for those patients with CIN diagnosis.