title: Deficiency of IgG subclass antibody response to tetanus toxoid associated with high serum IgA levels in IgA nephropathy.
abstract: In order to investigate IgG subclass response in IgA nephropathy (IgAN), 20 patients and 20 age and sex matched controls were systemically immunized with tetanus toxoid (TT). Nineteen/20 controls and 19/20 IgAN made a serum IgG anti-TT response of similar magnitude. However, significantly more patients with IgAN had undetectable amounts of at least one IgG subclass antibody to this antigen than controls (7/19 IgAN, 1/19 controls, p < 0.05). All individuals with an IgG subclass anti-TT deficiency lacked IgG1 and/or IgG4. Two patients made no IgG3 anti-TT (as well as no IgG1 and IgG4 anti-TT) but all individuals who responded to TT made IgG2 anti-TT. Total IgG subclass levels in IgAN did not differ from controls and no patient with IgAN had a total IgG subclass deficiency. Total serum IgA was significantly raised in IgAN (p < 0.002) and 6/7 IgAN with an IgG anti-TT subclass deficiency had a serum IgA level of over 3.2 milligrams compared to only 2/12 IgAN with no IgG subclass anti-TT deficiency (p < 0.01). The association of high serum IgA levels with IgG subclass deficiency to TT may be due to an abnormality in switching from IgG to IgA production in IgAN, or a manifestation of a defect of immunoregulation analogous to that proposed in IgA deficiency.
authors.affiliation: Department of Nephrology, Leicester General Hospital, UK.
authors.forename: L
authors.initials: L
authors.lastname: Layward
authors.forename: A C
authors.initials: AC
authors.lastname: Allen
authors.forename: S J
authors.initials: SJ
authors.lastname: Harper
authors.forename: J M
authors.initials: JM
authors.lastname: Hattersley
authors.forename: J
authors.initials: J
authors.lastname: Feehally
mesh_terms: D000328:Adult; D000917:Antibody Formation / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005922:Glomerulonephritis, IGA / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology*; D008297:Male; D013745:Tetanus Toxoid; D014611:Vaccination
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D013745:Tetanus Toxoid