Urinary C3dg and C5b-9 indicate active immune disease in human membranous nephropathy.
We have measured complement activation markers, C3dg and C5b-9 in plasma and urine from patients with idiopathic membranous nephropathy and IgA nephropathy. There was no significant difference in levels of plasma C5b-9 between the patient groups. However, high plasma concentrations of C3dg were associated significantly with IgA nephropathy with 45% of patients having levels over 25 U/ml (P less than 0.001). High concentrations of urinary C3dg and C5b-9 were associated significantly with membranous nephropathy (43% and 43% of the patient group, respectively) compared to patients with IgA nephropathy (10% and 0%, respectively, P less than 0.001). In a retrospective analysis of 31 patients with membranous nephropathy, 66% of patients with high initial urinary C5b-9 showed an unstable clinical course compared to 18% of patients with initially absent or low C5b-9 (P less than 0.001). We suggest that high urinary C5b-9 identifies those patients with a membranous lesion which retains an active immunological component contributing to the pathology of progressive glomerular damage.
Brenchley
P E
PE
Department of Renal Medicine, Manchester Royal Infirmary, England, United Kingdom.
Coupes
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Short
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O'Donoghue
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Ballardie
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Mallick
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D000328:Adult; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D015938:Complement Membrane Attack Complex / Q000652:urine*; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000503:physiopathology / Q000652:urine*; D006801:Humans; D007154:Immune System Diseases / Q000503:physiopathology / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000652:urine; D011951:Receptors, Complement / Q000378:metabolism*; D017464:Receptors, Complement 3d; D012189:Retrospective Studies
D000944:Antigens, Differentiation, B-Lymphocyte; D015938:Complement Membrane Attack Complex; D011951:Receptors, Complement; D017464:Receptors, Complement 3d