Clinical Features and Effects of Eradication on Helicobacter Pylori Positive 207 ITP Cases in Japan.

In 1998, Gasbarrini et al reported that in ITP cases with Helicobacter pylori (H.pylori) infection, elevation of platelet counts was observed by eradication of this bacterium. Since then, several reports from Italy and Japan confirmed the elevation of platelet counts after eradication. However, the characteristic background in the H.pylori positive ITP and eradication effects on platelet counts is unclear. On the other hand, reports from Spain, North Europe and USA could not show the evidence that eradication is effective on elevating platelet counts in H.pylori positive ITP.

Therefore, we designed a nationwide retrospective study in Japan to evaluate the incidence of H.pylori positive ITP cases and the effects of eradication on platelet counts and to clear above problems.

Four hundred and thirty-five ITP cases were enrolled over a period of one and half years (2002. 7~2003.12) from 12 hospitals. H. pylori infection was found in 300 cases(65%), who were significantly (P<0.005) older and showed hyperplastic megakaryocyte in bone marrow (P=0.011) comparison with negative cases. Eradication to H. pylori was performed in 207 H. pylori positive ITP cases and as a whole, the platelet count response was observed in 63% of eradication succeeded group. In the successful group, CR and PR rate were 23% and 42% respectively at 12 months after eradication. The platelet count response was significant in the successfully eradicated group (P<0.005) and the increased platelet count was maintained without ITP treatment for over 12 months. In conclusion, H. pylori infection was involved in most ITP patients over 40 years old in Japan and eradication therapy proved effective for increasing platelet counts even in splenectomy non-responsive cases and the platelet count response appeared one month after eradication. This evidence suggests that eradication therapy is the first line of treatment in H. pylori positive ITP patients.