Analysis of B- and T-cell clonality and HLA class II alleles in patients with idiopathic thrombocytopenic purpura: Correlation withHelicobacter pyloriinfection and response to eradication treatment

Abstract

Many authors have recently found a positive correlation between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP), the most common autoimmune hematological disorder. In order to clarify the pathogenic mechanism of H. pylori-associated ITP, we have investigated 52 consecutive ITP adult patients for Helicobacter pylori infection, B- and T-cell clonality and HLA class II alleles. Thirty-four ITP patients (65.4%) were infected by H. pylori and bacterium eradication was accompanied by a long-term platelet response in 17 (53.1%) of them. A B-cell clonality was found in three patients (5.8%, two patients H. pylori-negative and one patient H. pylori-positive). The ITP patients with H. pylori infection showed a HLA-DRB1*11, *14 and -DQB1*03 frequencies significantly higher and a -DRB1*03 frequency significantly lower than in H. pylori-negative patients. Moreover, an HLA-DQB1*03 pattern was associated with a higher probability of platelet response to eradication treatment. If our study documents the efficacy of eradication treatment in H. pylori-infected ITP patients, it may also help to identify different subgroups of ITP patients with probably different pathogeneses of thrombocytopenia and, finally, different responses to eradication treatment.

Helicobacter pylori infection and chronic immune thrombocytopenic purpura: long-term results of bacterium eradication and association with bacterium virulence profiles

“…51,52 Peripheral blood B-cell clonality has elsewhere been reported in a low percentage of infected patients with ITP. 53 No differences in the pattern of B-cell and T-cell clonality have been found between our infected patients with ITP and control participants. A prevalence of B-cell clonality was noted in 83% of our responsive patients versus the 25% of nonresponsive patients; a prevalence of T-cell clonality was present in 40% of responsive patients versus 25% of nonresponsive patients.…”

Association of Inflammatory Cytokine Gene Polymorphisms with Platelet Recovery in Idiopathic Thrombocytopenic Purpura Patients after the Eradication of Helicobacter pylori

“…Nomura et al[ 30] reported that HLA-DR4 and DRB1*0410 alleles attributed to an unfavorable and favorable response to corticosteroids, respectively and HLA-DRB1*1501 was associated with an unfavorable response to splenectomy. Veneri et al[ 31] found that the ITP patients with H. pylori infection showed HLA-DRB1*11, *14 and -DQB1*03 frequencies significantly higher and DRB1*03 frequencies significantly lower than in H. pylori -negative patients. Moreover, they showed that a HLA-DQB1*03 pattern was associated with a higher probability of platelet response to eradication of H. pylori .…”

Effects of eradication of Helicobacter pylori infection in patients with immune thrombocytopenic purpura: a systematic review

“…A genetic predisposition to response has been suggested by an Italian study, in which the presence of the HLA-DQB1*03 allele was associated with higher response rates. 28 In one study, a complete response was associated with no prior prednisone therapy, 22 and in another concomitant corticosteroid therapy was reported to be slightly more common in nonresponders than in responders. 25 Finally, 5 studies, including a total of 130 patients, reported no association between background characteristics and platelet response.…”