[Haemophilus parainfluenzae and IgA nephropathy].
IgA nephropathy (IgAN) was first reported by Berger in 1968, and characterized by diffuse IgA deposition in the mesangium. Patients with IgAN have usually episodic macroscopic hematuria accompanied with pharyngitis, gastroenteritis, bronchitis, or sinusitis. These findings suggest that IgAN is an immune-complex disease resulting from a poorly controlled mucosal immune response to environmental antigens to which the patient was chronically exposed. We reported the glomerular deposition of the outer membrane of Haemophilus parainfluenzae (OMHP) antigens and the presence of IgA antibody against OMHP in the sera of patients with IgAN. These suggest that Haemophilus parainfluenzae plays a role in the aetiology of this disease. This study was conducted to determine whether OMHP antigens induced immunohistologically evident glomerular deposition of IgA and C3 in C3H/HeN mice. Female C3H/HeN mice (4 weeks old) received intraperitoneal injection (HP-IP group), and oral administration (HP-PO group) of OMHP antigens. The control group similarly received intraperitoneal injection of PBS, and oral intake of ordinary water. The mice were sacrificed at 10, 20, 30, 40, 50 weeks after the start of the experiment. The HP-IP group showed glomerular deposition of IgA, C3 and OMHP antigens, glomerular changes (Mesangial hypercellularity and increase in mesangial matrix) after 20 weeks. The HP-PO group showed only mild deposition of IgA, and mild increase in mesangial matrix. These results suggest that OMHP antigens play a role in the glomerular deposition of IgA and C3 in C3H/HeN mice. This is the first use of OMHP antigens to establish an active model of IgAN.
Yamamoto
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C
Department of Clinical and Laboratory Medicine, Fukui Medical University.
Suzuki
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S
D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D005922:Glomerulonephritis, IGA / Q000276:immunology*; D006193:Haemophilus influenzae / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins