Mesangiocapillary glomerulonephritis in lambs. III. Quantitative and qualitative aspects of immunopathology.

Newborn Finnish Landrace lambs subsequently affected with mesangiocapillary glomerulonephritis (MCGN) were deficient in the third component of complement (C'3), serum levels being approximately 5 per cent. of those in unaffected lambs. Hypocomplementaemia persisted until symptoms of renal failure occurred at around 6-8 wk of age. Immunofluorescence examinations of renal cortex with antisera specific for IgG, IgM, IgA, C'3 and fibrin supported previous morphological evidence of a strong similarity between this disease and MCGN in man. Similar examinations of choroid plexus suggested that immune complexes containing IgG, IgM and C'3 were present in the interstitium.