Background: A relationship between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) has previously been reported. We determined the prevalence of H pylori infection in Japanese patients with chronic ITP and the effect of its eradication on platelet count.

Methods: The study population comprised 53 Japanese adults with chronic ITP and a platelet count of less than 100 x 10(3)/ micro L. A (13)C-urea breath test was performed to determine H pylori infection status. Those patients who were H pylori positive gave written informed consent and received eradication therapy. The effect of H pylori eradication on platelet count was evaluated up to 6 months after therapy. Clinical parameters were compared between responders to the therapy (increase in platelet count) and nonresponders, as well as between H pylori-positive and -negative patients.

Results: Of the 53 patients with chronic ITP in the study, 39 (74%) were H pylori positive. Of the 32 infected patients who received treatment, H pylori was successfully eradicated in 27 patients (84%). In 10 (37%) of these patients, this resulted in a favorable platelet response. A partial response was seen in 5 additional patients (19%). A significant (P<.001) increase in platelet count was demonstrated in patients in whom H pylori was successfully eradicated but not in patients who were unsuccessfully treated or in untreated patients. Current corticosteroid therapy was reported more often in nonresponders than in responders.

Conclusions: Eradication of H pylori may prove effective in increasing platelet count in H pylori-positive patients with chronic ITP.