This term has historically been used to refer to an ill-defined spectrum of changes which include mesangial matrix expansion, mesangial proliferation, basement membrane
thickening with double contours, and peripheral mesangial interposition, sometimes accompanied by focal segmental sclerosis. It is usually associated with marked proteinuria, often in the nephrotic range.
The definition of chronic transplant glomerulopathy has been refined in the Banff 97 Schema. The presence of double contours is now regarded as the most specific change, and graded under the 'cg' category. Mesangial matrix expansion is a potentially important but less specific finding which is graded separately under the 'mm' category.