title: Haemophilus parainfluenzae antigen and antibody in children with IgA nephropathy and Henoch-Schönlein nephritis.
abstract: Although the pathogenesis of immunoglobulin A (IgA) nephropathy and Henoch-Schönlein nephritis (HSN) remains uncertain, there is substantial evidence that they are immune complex-mediated diseases. Recently, Haemophilus parainfluenzae antigens were shown in the glomerular mesangium of adult patients with IgA nephropathy, and greater levels of IgA antibody against H parainfluenzae were also shown in the sera of adult patients with IgA nephropathy. The present study was performed to detect H parainfluenzae antigens and antibody against H parainfluenzae in children with IgA nephropathy and HSN. H parainfluenzae antigens in the mesangium were examined by indirect immunofluorescence, and antibody against H parainfluenzae was examined by enzyme-linked immunosorbent assay. Diffuse global staining of the mesangium with rabbit antisera against H parainfluenzae was shown in 10 of the 32 patients (31%) with IgA nephropathy and 12 of the 34 patients (35%) with HSN. Conversely, only 2 of the 47 patients (4%) with other renal diseases showed staining of glomeruli with rabbit antisera against H parainfluenzae (IgA nephropathy versus other renal diseases, P = 0.003; HSN versus other renal diseases, P = 0.0006). Patients with IgA nephropathy and those with HSN showed significantly greater levels of plasma IgA1 antibody against H parainfluenzae than patients with other renal diseases (IgA nephropathy versus other renal diseases, P = 0.008; HSN versus other renal diseases, P = 0.025). These findings suggest that H parainfluenzae has a role in the cause of these two conditions in a subset of patients.
authors.affiliation: Faculty of Health Science and Department of Pediatrics, Kobe University School of Medicine, Kobe, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ogura
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Shirakawa
authors.forename: M
authors.initials: M
authors.lastname: Masuda
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Iijima
authors.forename: N
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial / Q000032:analysis*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005920:Glomerular Mesangium / Q000276:immunology / Q000382:microbiology*; D005922:Glomerulonephritis, IGA / Q000382:microbiology*; D006190:Haemophilus / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D011695:IgA Vasculitis / Q000382:microbiology*; D007070:Immunoglobulin A / Q000032:analysis; D007674:Kidney Diseases / Q000382:microbiology; D008297:Male; D009393:Nephritis / Q000382:microbiology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A