RESPONSE TO MUCOSAL ANTIGEN CHALLENGE IN IGA NEPHROPATHY

While IgA nephropathy (IgAN) is characterized by the deposition of glo merular IgA, the source of the deposited IgA is not known, with both t he mucosal and systemic IgA systems being implicated. In order to inve stigate mucosal and systemic antibody production to mucosal antigen ch allenge in IgAN, 9 patients and 11 controls were immunized intranasall y with tetanus toroid (TT). There was no significant difference in the serum or saliva IgG, IgA, IgA1, or IgA2 antibody production to TT. Ho wever, in IgAN there was an increase of in vitro IgA anti-TT productio n in Epstein-Barr virus transformed cultures of peripheral blood lymph ocytes taken after mucosal immunization. This increase in traffic of i mmunocompetent cells between the systemic and mucosal systems could pl ay a role in the link between the mucosa and glomerulus in IgAN. Syste mic immunization with TT following mucosal priming did not result in a ny difference in the antibody response between patients and controls, There was no evidence from this study that mucosal immunization result s in an enhanced antibody response in IgAN or that mucosal priming alt ers the subsequent systemic antibody response.