The Evolution Of Morphological Variants Of Focal Segmental Glomerulosclerosis: A Repeat Biopsy-based Observation

Objective:To observe the change of classification of idiopathic focal segmental glomerulosclerosis (FSGS) in patients based on repeat renal biopsy and analyze the relationship between classification changes and clinical manifestations.Methodology:Twenty patients with idiopathic FSGS who underwent more than two renal biopsies were enrolled, the clinical and pathological features of these patients were reviewed, the changes in pathological classifications and the relationship between the response to treatment and the prognosis were analyzed. The classification of FSGS were subdivided into collapsing, tip, cellular, perihilar, not-otherwise-specified according to the 2004 Columbia classification.Results:There were fourteen male and six female who underwent repeat renal biopsy and all of which had been proven to be idiopathic FSGS, and three of them underwent 3 renal biopsy. At the first biopsy time, the patients had a mean age 23.60 ±8.91 year-old, proteinuria of 7.15±3.92 g/24h, serum albumin of 22.85±7.24 g/L, serum creatinine of 1.30±0.82 mg/dl, the number of glomeruli of 24±10.9 per biopsy. There were 5 patients with collapsing variant,5 with tip lesion variant,5 with cellular variant,4 with perihilar variant and 1 with not-otherwise-specified variant(NOS). At the second biopsy time, the patients had a mean age of 25.70±9.62 year-old, proteinuria of 7.36±4.30 g/24h, serum albumin of 21.27±6.66 g/L, serum creatinine of 1.57±0.96 mg/dl, the number of glomeruli of 26±8.4 per biopsy. There were 3 patients with collapsing variant,3 with tip lesion variant,3 with cellular variant,1 with perihilar variant and 10 with NOS. The time interval between the first and second renal biopsy was 9.5 (5.8,16.0) months. After second biopsy, there were 10 patients with changing in classification of FSGS,7 of which developing from other variants to NOS.Conclusion:The changing in pathological classification of FSGS during the disease progression is presented. The most common pathological variant of FSGS is NOS. There are frequently observed that other variants would transform to NOS with disease progression.