Steroid resistant nephrotic syndrome: role of histopathology.

This study was conducted to (1) see the histopathological distribution of different subtypes in steroid resistant nephrotic syndrome (SRNS) and (2) compare the clinical, biochemical parameters and outcome between Minimal Change Disease (MCD) with non-MCD subtypes in response to immunosuppressive therapy. A retrospective analysis was done of data on all biopsy proven children with idiopathic SRNS (no response to 4 weeks of standard prednisone therapy (60 mg/m(2)/day)) referred to our institute over last 12 years. They were treated with one of the following medications: oral or intravenous cyclophosphamide, cyclosporine or combination of dexamethasone and azathioprine. A comparison was done of the demographic clinical and biochemical features different histopathologies. We studied 136 children with SRNS (100 M, 36 F). They accounted for 15.1%(136/900) of all children with idiopathic nephrotic syndrome. Focal segmental glomerulosclerosis (FSGS) was the commonest 80/136 (59%), followed by MCD (17.6%). Children with non-MCD had a significantly greater prevalence of microhematuria as compared to MCD. The other baseline clinical and biochemical features including the glomerular filtration rate (GFR) were similar. After a mean follow up of 46 (8-148) months, a significantly greater children with non-MCD 65/112) continued to be proteinuric as compared to the MCD (3/24) (p=0.0001). FSGS was the commonest cause of SRNS in our patient population. Children with SRNS secondary to MCD are more likely to achieve remission as compared to non-MCD subtypes and have a better long-term prognosis. Hence kidney biopsy is of significant prognostic value in SRNS.