Many studies have supported the correlation between infection and the onset of IgAV, and the evidence can be described as follows: The prevalence of IgAV is seasonal, consistent with the epidemiological characteristics of some respiratory or enteropathogenic microorganism (118); IgAV recurrence is associated with reinfection of certain pathogenic microorganisms, for that IgAV patients with Helicobacter pylori (Hp) infection could achieve remission via Hp eradication, but relapsed after re-infection with Hp (119, 120). This evidence concerns the gene HP and infection.