Autoimmune diseases and Helicobacter pylori infection.

In the last few years several studies have been performed on the association between H. pylori infection and a miscellany of extragastric disorders which also include autoimmune diseases. In particular, emerging evidence seems to give a potential role for H. pylori in ischaemic heart disease via a cross mimicry between antibodies against heat shock protein 65 which are produced in the consequence of infection, but which are also expressed in atherosclerotic lesions. In cases of healing of Sjogren syndrome and Schonlein-Henoch, purpura have also been reported. A recent study, moreover, showed that eradication of H. pylori infection may be effective in the disappearance of autoimmune thrombocytopenia. Finally, a role for H. pylori has also been postulated in other autoimmune diseases such as membranous nephropathy and some acute immune polyneuropathies. The mechanisms behind these clinical observations still remain unclear. However, if confirmed, these findings could revise the diagnostic and therapeutic approach to diseases previously considered as idiopathics.