RESUMO
To test the role of T helper cell Th1 immunity we recruited 24 patients with idiopathic thrombocytopenia associated with H. pylori seropositivity. They were divided into 2 groups: 12 with immune-mediated thrombocytopenia [Group 1] and 12 with non-immune mediated thrombocytopenia [Group 2]. We also recruited 10 individuals seronegative for H. pylori [Group 3] as controls. Initial platelet count was significantly lower in Group 1 than Group 2. H. pyloriwas eradicated in 10 of 12 patients in Group 1 and in all patients in Group 2. Transient improvement [< 3 months] in the platelet count occurred in only 2 patients in Group 1 while improvement for > 6 months was observed in all patients in Group 2. There was a statistically significant direct correlation between platelet count and levels of TNF- and IFN-gamma in both study groups, while a non-significant correlation was seen in Group 3. Thus, H. pyloriinfection should be considered in the differential diagnosis of all cases of thrombocytopenia, and should be eradicated in all H. pylori-positive patients with thrombocytopenia