Is the host responsible? -- the role of the immune system in Helicobacter pylori infection.

Helicobacter pylori is the primary aetiological agent of chronic gastritis and a necessary factor in most peptic ulcer disease. To date the majority of studies, which have examined factors predictive of disease outcome, have concentrated on bacterial virulence factors. Recent evidence suggests that the immune response might be responsible. Fc receptors polymorphisms have been implicated in autoimmune diseases and persistent bacterial infections. Individuals who are H. pylori positive and homozygous recessive for the FcgammaRIIa receptor may have a higher risk of developing peptic ulcer disease rather than gastritis.