Minimal change nephrotic syndrome(MCNS) is also known as nil lesion or lipoid nephrosis; more than 85% to 90% of all children with nephrotic syndrome have this condition.
It almost always presents as insidious or sudden onset of the nephrotic syndrome in children aged 2 to 8 years with a ratio of 2:1. In adults, accounts for about 20%, with a more equal male-to-female ratio. As children approach teen age years and early adulthood, the incidence of MCNS as a cause of nephrotic syndrome diminishes.
In adult patients the association of MCNS with the use of nonsteroidal anti-inflammatory agents and Hodgkin’s disease must be kept in mind. Laboratory features include those of the typical nephrotic syndrome with bland urinary sediment, normal renal function(unless there is severe volume contraction), and normal complement levels. Histologicall light microscopy is normal(hence the term nil lesion and no immunoglobulins or complement deposition is the foot processes, which is the result of the proteinuria. MCNS, especially in children, is extremely responsive to treatment with corticosteroids. Patients are given a trial of 60 mg/m2/day in children and about 2 mg/kg/day in adults. At 4 weeks, alternate-day therapy with 35 mg/m2 in children and 0.9 mg/kg in adults is begun and continued for 4 to 8 more weeks, with a tapering regimen given over the next 4 to 6 months.
Eighty-five to 90% of all patients with MCNS respond to this protocol(usually by the fourth week in children and the eighth week in adults). Adults older than 40 may require 16 to 20 weeks of corticosteroid therapy before a complete remission occurs. After a remission, about 70% of patients have one or more episodes of relapse. The remainder become frequent relapsers(more than twice a year) or corticosteroid dependent. These patients may benefit from adjunctive therapy with cytotoxic alkylating agents such as chlorambucil(0.1 0.2 cyclophosphamide mg/kg/day) for 12 weeks.
However, there are significant risks associated with the use of these agents, in cluding gonadal failure and carcinogenesis, particularly with long-term use or in combination with corticosteroids.