Idiopathic collapsing focal segmental glomerulosclerosis in an 81-year-old Japanese woman: a case report and review of the literature.

Focal segmental glomerulosclerosis (FSGS) is classified into five variants, with the collapsing variant being the most rare. Collapsing FSGS is characterized by a black racial predominance and is often associated with human immunodeficiency virus-associated nephropathy. However, the number of idiopathic cases is increasing and the presentation of non-black patients becoming more routine. Our analysis of 15 previous reports investigating FSGS variants shows that the collapsing variant accounts for 10.6 % of FSGS cases and its average age of onset is 32 years old. The current case is one of the oldest cases of idiopathic collapsing FSGS identified, being an 81-year-old Japanese woman. She presented with severe renal insufficiency (serum creatinine 7.9 mg/dL, albumin 1.5 g/dL) and so underwent hemodialysis immediately. Urinalysis demonstrated 3+ proteinuria and 3+ hematuria and the serological work up was all negative. Renal biopsy showed wrinkling of capillary walls with collapse lumens in every glomerulus, without endothelial tubuloreticular inclusions. Combined treatment with steroids, cyclosporine and low-density lipoprotein apheresis increased urine output slightly but she was unable to withdraw from hemodialysis and died 3 months later. This variant is reported to have the highest rate of progression to end-stage renal disease, regardless of the therapeutic intervention. However, there are also examples of cases with partial or complete remission in the literature. Progressive cases, like the current case, seem to be difficult to induce remission in, so it is important to diagnose idiopathic collapsing FSGS at an early stage by performing a renal biopsy, even in elderly patients.