Helicobacter pylori: An Underrated Cause of Immune Thrombocytopenic Purpura. A Comprehensive Review

Abstract

Idiopathic thrombocytopenic purpura (ITP) is the autoimmune-mediated destruction of platelets. ITP is a diagnosis of exclusion after other identifiable etiologies have been ruled out. After the first report by Gasbarrini et al. (1998) showing rising platelet counts in ITP patients following Helicobacter pylori (HP) eradication therapy, there is growing evidence that highlights the role of HP in triggering ITP. However, the exact pathophysiology of HP-associated ITP is still unclear, but many theories have been implicated in this regard. According to various reports, the postulated mechanisms for the role of HP in cITP include molecular mimicry, increased plasmacytoid dendritic cell numbers, phagocytic perturbation, and variable host immune response to HP virulence factors. One famous theory suggested molecular mimicry between platelet surface antigen and bacterial virulence factor, i.e. cytotoxin-associated gene A (CagA). It is thought that a chronic inflammatory response following an HP infection induces the host autoantibodies' response against CagA, which cross-reacts with platelet surface glycoproteins; therefore, it may accelerate platelet destruction in the host reticuloendothelial system. However, further studies are mandated to better understand the causal link between ITP and HP and study the role of biogeography. Nowadays, it is recommended that every patient with ITP should undergo HP diagnostic testing and triple therapy should be administered in all those candidates who test positive for HP infection. In our review, there were a few pregnant female ITP patients who took HP eradication therapy mainly after 20 weeks of gestation without maternal or fetal worst outcomes. However, large-scale studies are advisable to study the adverse fetal outcomes following triple therapy use.

Keywords: h. pylori; helicobacter pylori infection; immune thrombocytopenia; immune thrombocytopenic purpura (itp); itp.