Dense Deposit Disease
Dense deposit disease (DDD) is a specific form of C3G that is classified by the presence of dense osmiophilic intramembranous deposits seen on electron microscopy. The IF criterion used to classify C3G captures ~ 90% of DDD cases.
Historically, DDD was classified as a form of MPGN (Type 2). However, diverse patterns of glomerular injury have been identified in DDD that also includes mild mesangial hypercellularity, crescentic glomerulonephritis or an acute proliferative and exudative pattern. An MPGN pattern of injury is observed in only 25% of DDD cases.