title: Serum IgA class anti-IgA antibody in IgA nephropathy.
abstract: IgA class anti-IgA antibody was sought by an immunoabsorbent technique in sera from patients with IgA nephropathy (IgA-N, n = 62), other forms of primary glomerulonephritis (PGN, n = 41), seropositive rheumatoid arthritis (RF-positive, n = 18) and normal controls (c, n = 50). IgA-N (31%) and RF-positive (56%) patients showed a significant increase in IgA anti-IgA antibody levels. The subclass of IgA anti-IgA antibody was predominantly IgA1 in both IgA-N and RF-positive patients. Size analysis revealed the dimer/monomer ratio to be significantly increased in IgA-N patients compared with that of RF-positive patients (p = 0.03). These results indicate the possible existence of the dimeric form of IgA class anti-IgA antibody in the circulation of IgA-N patients.
authors.affiliation: Department of Medicine, School of Nursing and Medicine, Kitasato University, Sagamihara City, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hiki
authors.forename: M
authors.initials: M
authors.lastname: Saitoh
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000097:blood* / Q000737:chemistry / Q000145:classification; D000918:Antibody Specificity; D005922:Glomerulonephritis, IGA / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012217:Rheumatoid Factor / Q000097:blood
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012217:Rheumatoid Factor