Histologic variants of primary focal segmental glomerulosclerosis: presentation and outcome

The clinical significance of histologic variants of primary focal segmental glomerulosclerosis (FSGS) remains unclear. With the aim to determine presentation and outcome of the variants of FSGS in a hispanic population, we studied our cases of this glomerulopathy.

In this retrospective study, all renal biopsies with FSGS (1998-2009), were classified according to the Columbia's classification. We analyzed histological, clinical and follow-up data and compared among variants.

Among 291 cases, 224 (77.0%) corresponded to NOS variant, 40 cases (13.7%) to tip variant (TIP), 14 cases (4.8%) to perihilar (PH), 10 cases (3.4%) to collapsing (COLL) and three cases (1.0%) to cellular variant (CELL). Median age: 26 years (range 1 to 79); 74 patients (25.4%) were < 15 years of age. Hypertension and renal dysfunction were more frequent in PH and COLL cases. PH presented frequently as nonnephrotic proteinuria. There were fewer histologic chronic lesions in TIP cases. There was remission in 23.5% of patients with NOS, 57.7% of patients with TIP, 22.2% of patients with COLL and 0 patients with PH (p < 0.01). Chronic kidney disease (CKD) was less frequent in TIP than in the other variants (p = 0.03). There were not statistical differences for end-stage renal disease among variants.

Glomerular histological appearance is not a good indicator of outcome. COLL is a disease with many differences to the other variants and bad prognosis; PH is a variant mainly of adults, with frequent evolution to CKD. TIP appears as a less aggressive, although not benign, variant.