Alcohol abuse-related mesangial glomerulonephritis: immunoelectron microscopy

Immunoelectron microscopy, using post-embedding immunohistochemistry with colloidal gold, was performed on renal samples from forensic autopsies. We confirmed that electron-dense deposits seen in alcohol abuse-related mesangial nephritis correspond to immunoglobulins, as has been shown previously by others in idiopathic cases. We investigated seven control samples and 13 specimens from individuals with evidence of alcohol abuse, six of whom had mesangial nephritis with IgA deposition. We found concentration of the gold particles over large electron-dense deposits in four of six cases of mesangial nephritis, confirming that they correspond to the IgA shown by immunofluorescence. Furthermore, a similar concentration of gold particles was not observed in control cases or in alcoholics without mesangial glomerulonephritis (4/6 vs 0/14; p = 0.005). IgM, seen as small aggregates, was confirmed in only two of six of the same cases. This is the first time that immunoelectron microscopy is performed on tissues obtained post mortem.