Thomas DB et al. (2006) Clinical and pathologic characteristics of focal segmental glomerulosclerosis pathologic variants. Kidney Int 69: 920–926

A standardized classification system has been devised to group focal segmental glomerulosclerosis (FSGS) variants into five categories based on histologic features. Thomas et al. used the Glomerular Disease Collaborative Network patient registry to investigate whether these subgroups represent distinct pathologic variants with different clinical outcomes.

The registry contains patient data from time of renal-biopsy-based diagnosis to onset of end-stage renal disease or death. In total, 197 patients from the registry were included in this evaluation—22 with collapsing FSGS, 34 with tip lesion FSGS, 6 with cellular FSGS (not included in statistical comparisons), 52 with perihilar FSGS and 83 with FSGS not otherwise specified.

Common features of each variant were nephrotic syndrome, hypertension and renal insufficiency, but some other characteristics were shown to be variant-specific. For example, patients with collapsing FSGS usually had severe nephrotic syndrome and substantial renal insufficiency, and the worst 1-year and 3-year survival rates of all the variants. Tip lesion FSGS was associated with severe nephrotic syndrome, but patients with this variant had the highest remission rate (50%) and highest 3-year survival rate (76%). Hypertension was most common in patients with perihilar FSGS and FSGS not otherwise specified. The majority of patients with collapsing FSGS were African American (91%); only 15% of those with tip lesion FSGS, however, were in this ethnic group.

The authors conclude that FSGS does indeed encompass a range of distinct disease variants with different demographics, clinical symptoms and outcomes. Recognition of these variants will enable treatments to be tailored to the individual.