Influence of Helicobacter pylori on platelets after bone marrow transplantation from unrelated donors

This study was performed to clarify the influence of Helicobacter pylori on the platelet count in patients undergoing bone marrow transplantation (BMT) from unrelated donors. Of 23 consecutive patients undergoing BMT from unrelated donors, the H. pylori antibody test did not change from before conditioning until recovery of the platelet count in 15 patients. These patients were classified into H. pylori antibody-positive (n=8) and -negative (n=7) groups. In the H. pylori antibody-positive group, the platelet count exceeded 20 x 10(9)/l significantly faster after BMT, than in the H. pylori antibody-negative group. When myelosuppression was most severe, the interleukin-6 (IL-6) level was significantly higher in the positive group than in the negative group (67.0+/-10.6 vs 9.9+/-2.4 pg/ml, P<0.05). In addition, the thrombopoietin level was significantly lower in the positive group than in the negative (510.1+/-313.9 vs 3209.1+/-2006.7 pg/ml, P<0.01). These data suggest that H. pylori infection accelerates recovery of the platelet count after BMT from unrelated donors, possibly by stimulating IL-6 production.