Background: Chronic idiopathic thrombocytopenic purpura (CITP) is an autoimmune disease with low platelet count and potentially bleeding tendency. Although autoimmune mechanisms play a crucial role in the disease yet in 20% of cases underlying diseases such as Helicobacter pylori (HP) infection can be involved.

Objectives: The aim of this study was to evaluate effects of H. pylori eradication therapy on platelet count in CITP patients with H. pylori infection.

Patients and Methods: During this clinical trial, performed from September 2011 to August 2012, twenty-three patients with CITP were divided in two groups, including one group with H. pylori infection and the other without infection. After determination of baseline platelet count in the two groups, patients with H. pylori infection underwent eradication therapy. Both groups were followed up for six months and platelet counts were checked at one-month intervals and finally, changes in platelet counts were statistically compared before and after treatment and also between the two groups.

Results: From a total of 23 patients with CITP, 43% (10) of the cases were H. pylori positive and after eradication therapy, eight patients (80%) were successfully treated. Helicobacter pylori eradication therapy causes a statistically significant difference between the mean platelet count before and after HP eradication therapy.

Conclusions: Helicobacter pylori infection has a significant effect on platelet count in patients with CITP and H. pylori eradication therapy should be considered as an important factor in platelet count recovery in CITP patients.