IGHA1 and IgA glomerulonephritis: Moreover, patients with IgA nephropathy and Helicobacter pylori infection showed a greater rate of IgA anti-Helicobacter pylori seropositivity and a more pronounced IgA and IgG anti-Helicobacter pylori response compared to patients without renal disease, the latter predominantly existing of polymeric IgA1, IgG2, and IgG3 in the diseased group [42].