Immunofluorescent studies on IgA nephropathy: type IV collagen and glomerular basement membrane component detected by Goodpasture's syndrome serum and laminin.

A study of immunofluorescence of unfractionated Type IV collagen, non-collagenous (NC-1) domain of Type IV collagen, basement membrane (GBM) component detected by Goodpasture's syndrome patient's serum and laminin (LN) in the glomeruli from 10 patients with IgA nephropathy was described. Type IV collagen, non-collagenous (NC-1) domain of Type IV collagen, GBM component or LN was observed linearly in the glomerular capillary walls in all patients with IgA nephropathy examined. The deposition of IgA, IgM or C3 was marked in the glomerular capillary walls in patients in the moderate or advanced stage of IgA nephropathy. However, the staining of Type IV collagen, GBM component or LN in such walls was not altered by the depositions of IgA, IgM and C3. In particular, a wrinkled pattern of NC-1 domain of Type IV or GBM component was detected in the glomerular capillary walls of totally sclerotic glomeruli in some patients with IgA nephropathy. It appears that the deposits of IgA and/or C3 did not influence the major components of glomerular capillary walls in patients with IgA nephropathy. It is concluded that the initiating factors of the collapse and/or sclerosis of glomerular capillary walls might be due to various factors other than the deposition of glomerular IgA-dominant immune-complexes in patients with IgA nephropathy.