MC Chiu

Nephrotic syndrome is a common childhood problem and features consist of heavy proteinuria with hypoalbuminaemia. Complications include gross oedema, hypovolaemia, infection and thrombosis. According to ISKDC, minimal change diseases constitutes more than 75% of all primary nephrotic cases, and others are mesangioproliferative glomerulonephritis, focal segmental glomerulosclerosis, focal proliferative glomerulonephritis, membrano-proliferative glomerulonephritis and membranous nephropathy. At presentation, renal biopsy is usually not necessary unless there are atypical features suggesting a diagnosis not that of minimal change GN, like macroscopic haematuria, persistent hypertension, azotaemia and low C3. In later management, it is indicated for steroid resistance. As for frequent relapses, a biopsy is usually not necessary, but can be done with discretion when considering a 'third' line drug treatment. A course of steroid is nearly always given at presentation. According to ISKDC, the regimen is prednisone 60mg/m² for 4 weeks followed by 40 mg/m² on alternate day for another 4 weeks. The UK regimen is slightly different in that the initial high dose is given until remission is induced instead of a - 4 weeks course; and APN gives a longer course of 6 weeks for both initial high dose and subsequent alternate day maintenance. The latter long course claims to have less relapses with no additional side effects. For non-responders, 3 pulses of methylprednisolone can be given to induce remission and if fail, patients can be managed as steroid resistance. For infrequent relapses, a course of steroid can be given for each relapse. For frequent relapses and/or steroid dependence, 6 months of steroid given on alternate day can be given together with levamisole at 2.5mg/kg on alternate day, which is a antihelminthic found to be useful for steroid dependence. If steroid toxicity is a problem, either cyclophosphamide or cyclosporin A can be used. Cyclophosphamide has a longer effect even after the drug is discontinued whereas for cyclosporin A, the effect is maintained only while the patient is on treatment and thus relapses quickly occur once the drug is discontinued. However, cyclophosphamide has a possible side-effect of oligospermia when cummulative dose exceeds 250mg/kg, and thus the drug need to be used with caution especially in pubertal boys. Dosage for cyclophosphamide is 2.5mg/kg for 8 - 12 weeks and for cyclosporin A 5 mg/kg/day. The latter need to have drug level monitored as nephrotoxicity is a possible side-effect. As for steroid resistance, a renal biopsy is warranted to identify the type of renal pathology. Methylprednisolone, alkylating agents like cyclophosphamide or immunosuppressant like cyclosporin A are agents that have been used with some success. In the management of nephrotic syndrome, the possible side-effects of the powerful immunosuppressive agents need to be carefully balanced against the complications of the illness.