including lamellation, irregular thickening and thinning, disruption, and partial lysis are associated with subendothelial and/or subepithelial immune complex deposits, and also tend to be associated with more severe histologic glomerular lesions (crescents, diffuse mesangial hypercellularity).
The rationale for performing such staining on all cases of suspected TBMN is that heterozygous carriers of X-linked Alport syndrome (Figure 4, B), individuals with autosomal recessive Alport syndrome (Figure 4, C), and even some children with X-linked Alport syndrome (Figure 4, D) may show predominantly thin GBMs with little or no splitting or lamellation by EM.
The classic ultrastructural picture of Alport syndrome is characterized by alternating zones of thinning and thickening of the GBM (the former tending to predominate earlier, and the latter in more advanced lesions, particularly in males with X-linked disease), splitting and lamellation of the GBM with loss of the normal lamina densa, small granules within the GBM, and an irregular outer contour of the GBM (4,9,11,48-50) (Figure 5, A through C).
Ultrastructurally, the GBM presents alternating areas of thinning and thickening, splitting, lamellation, and granular inclusions in the lamina densa.
The GBM of the male patient with AS measured 324 nm and presented typical changes of AS (namely, alternating areas of thin and thick GBM with splitting, lamellation, and granular inclusions).