Helicobacter pylori protein that binds to and activates platelet specifically reacts with sera of H. pylori-associated chronic immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by antiplatelet antibodies and/or CD8 + T cells, resulting in the destruction of platelets and decreased platelet counts. Helicobacter pylori that persistently colonizes the stomach causes various disorders, including extragastric diseases such as chronic ITP (cITP). Several studies have reported increased platelet counts in H. pylori-infected cITP patients with eradication treatment and also the pathophysiological pathways involving cross-reaction of antibodies against H. pylori with platelets, the modulation of Fcr gamma receptors balance and others. We previously reported an immunocomplex pathway comprising H. pylori low-molecular-weight (LMW) antigens, their antibodies, and platelets, involved in the development of H. pylori-associated cITP; however, the LMW antigens were not identified. In the present study, we demonstrated that the H. pylori LMW antigen of the immunocomplex was identified as Lpp20 of outer membrane proteins. Lpp20 could bind to platelets and specifically react with sera of H. pylori-associated cITP patients.

Automated summary

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by antiplatelet antibodies and/or CD8 + T cells, and it may have a certain association with Helicobacter pylori infection, possibly leading to chronic ITP through various pathophysiological pathways. Studies have found that the H. pylori LMW antigen Lpp20 can bind to platelets and specifically react with sera of H. pylori-associated chronic ITP patients.