Cyclosporin A in the treatment of childhood glomerulonephritis

Long-term treatment of focal segmental glomerulosclerosis in children with cyclosporine given as a single daily dose

Cyclosporine (CsA) has been successfully used for treatment of children with focal segmental glomerulosclerosis (FSGS) and nephrotic syndrome (NS) for the last decade. Response rates of 50% to 100% have been reported using twice-daily dosing of 5 to 32 mg/kg/d, achieving trough blood levels of 70 to 500 ng/mL. Treatment has been associated with a high incidence of side effects, including nephrotoxicity, hypertension, gingival hyperplasia, and hirsutism. To determine whether once-daily low-dose CsA could minimize side effects and still induce remission, 21 children with biopsy-proven FSGS and NS, each treated with CsA, 4.6 +/- 0.8 mg/kg/d, with no predetermined target trough blood levels, were studied. Eleven of 21 children (52%) attained complete remission and 5 of 21 children (24%) attained partial remission, for a total response rate of 76%. Mean time to response was 2.8 +/- 0.8 months, and mean duration of therapy was 20.6 +/- 13.7 months. CsA dosage was tapered or stopped in 9 responders; 3 of these patients maintained remission at last follow-up 6 to 13 months later, and 6 patients relapsed at 1.5 to 18.7 months (mean, 8.7 months). Five of these 6 patients responded again when CsA therapy was restarted or the dosage was increased. Twelve of 16 responders were still being administered CsA at last follow-up 11 to 60 months (mean, 24.6 months) later. Five of 21 patients (24%) had no response to CsA during 2 to 27 months of therapy; 4 of these 5 patients developed end-stage renal disease after CsA therapy was stopped. Side effects of CsA therapy were minimal: 1 patient each developed new-onset hypertension or gingival hyperplasia, and no patient had hirsutism or nephrotoxicity. Single daily low-dose CsA appears to be effective for long-term treatment of children with FSGS and NS, with fewer side effects than twice-daily dosing.

Steroid-resistant, cyclosporine-responsive, relapsing nephrotic syndrome

Eighteen children with steroid-resistant nephrotic syndrome received cyclosporine A (CsA), including 7 patients with minimal change disease, 4 with focal segmental glomerulosclerosis and 7 with mesangial hypercellurarity. Doses were adjusted to maintain whole blood trough levels at 80-200 ng/ml and ranged from 5 to 10 mg/kg (mean 7 mg/kg). Fourteen patients responded after 2 months of therapy with either a complete or partial remission, and received a total of 12 months of CsA with low-dose corticosteroids. Remission rates were similar among the three histological types, although complete remissions occurred more commonly in minimal change disease, while the other two histological types tended to have partial responses. Serum creatinine values ranged from 0.3 to 1.2 mg/dl at the start of treatment and were stable in 17 of 18 patients during CsA therapy. CsA was discontinued after 12 months in 11 responders. Relapses were a significant problem. Nine patients had 16 relapses, all occurring within 6 months after discontinuing CsA; 13 of 16 relapses responded to CsA and corticosteroids. Five children had multiple relapses. Three patients who initially responded to treatment had CsA-resistant relapses. There were no differences among the histological types with respect to the occurrence of relapses or response to CsA after relapsing. Four patients developed chronic renal failure, including 2 of 4 who failed initial therapy and 2 of 3 who developed CsA-resistant relapses. In conclusion, initial therapy with CsA was effective in resolving nephrotic syndrome in steroid-resistant patients. However, CsA dependency, frequent relapses and the development of chronic renal failure presented significant problems.

Cyclosporin therapy in steroid-dependent nephrotic syndrome

Five children with multiple relapsing steroid-dependent nephrotic syndrome were treated with continuous cyclosporin for periods ranging from 18 to 48 months. Renal biopsy showed mild mesangial proliferation in three of the children and minimal change in two. All children previously had been treated with cyclophosphamide. Cyclosporin was started during remission at 5 mg/kg per day. If a relapse occurred the dose was increased until a trough blood level of 100-250 ng/mL (HPLC) was achieved. In the initial 12 months of treatment, the mean number of relapses decreased from 6.4 +/- 0.54 (s.d.) per annum to 1.6 +/- 1.3 per annum (P < 0.01). Cyclosporin was effective in maintaining long-term remission in four of the five patients. Side effects included hypertrichosis (5) and gum hyperplasia (1). The mean creatinine clearance decreased from 126 +/- 16 to 97 +/- 22 mL/min per 1.73 m2 (P = NS). A renal biopsy in all five patients after 12 months therapy showed no nephrotoxicity. A further biopsy in one patient after 4 years therapy showed interstitial fibrosis. Cyclosporin should be considered in children with steroid-dependent nephrotic syndrome who show signs of steroid toxicity and have only a short remission period after cyclophosphamide. Serial renal biopsies are recommended if prolonged therapy is used.

A randomized trial of cyclosporine in steroid-resistant idiopathic nephrotic syndrome

To compare the efficacy (induction of remission) and safety of cyclosporine (CsA) with those of supportive therapy in patients with steroid-resistant idiopathic nephrotic syndrome (INS), we organized an open, prospective, randomized, multicentric, controlled study for parallel groups, stratified for adults and children. Forty-five patients with steroid-resistant INS were randomly assigned to supportive therapy or CsA (5 mg/kg/day for adults, 6 mg/kg/day for children) for six months, then tapered off by 25% every two months until complete discontinuation. Four patients were lost to follow-up. During the first year 13/22 CsA-treated patients versus three of 19 controls attained remission of the nephrotic syndrome (P < 0.001). A symptom score was assessed at time 0 and at six months. The mean score significantly decreased in the CsA group (P < 0.001), but remained unchanged in the controls. At month 6 the mean urinary protein excretion, the mean serum proteins and plasma cholesterol had significantly improved in the CsA group but were not changed in the controls. There were no significant differences in serum creatinine and creatinine clearance between treatments (interaction time* treatments, P = 0.089 and P = 0.935, respectively) at month 6 versus basal. The CsA-related side-effects were mild; no significant difference in blood pressure between the two groups was seen at any time. This study shows that CsA can bring about remission in some 60% of patients with steroid-resistant INS. In patients with normal renal function and without severe hypertension, CsA at the therapeutic scheme adopted did not produce severe renal or extrarenal toxicity.

Treatment of the nephrotic syndrome with cyclosporin A

The three main causes of primary nephrotic syndrome are minimal change nephropathy, focal glomerulosclerosis and membranous nephropathy. Corticosteroids obtain remission of proteinuria in most patients with minimal change nephropathy. Many patients, however, show either frequent relapses or steroid dependency. A short course of cyclophosphamide or chlorambucil can achieve stable remission in many of these patients but alkylating agents cannot be repeated, their toxicity being cumulative. Analyses of the available studies showed that some 80% of patients can be maintained in remission with cyclosporin A (CsA) but relapse occurs when the drug is stopped. Severe side effects are rare. In particular, the mean values of creatinine clearance did not deteriorate in cyclosporin-treated patients and repeat renal biopsy showed only mild changes in some patients. There is no definite treatment for focal glomerulosclerosis. An analysis of 10 clinical trials showed that some 17% of nephrotic patients may enter complete remission of proteinuria and another 13% may attain partial remission of the nephrotic syndrome with CsA. There is concern over the use of this drug since cases of irreversible renal dysfunction have been reported. However, retrospective reviews of the available studies showed that the mean serum creatinine levels did not modify if patients had normal renal function when given CsA. A 6-month course of methylprednisolone and chlorambucil may obtain remission of the nephrotic syndrome in some 60% of patients with membranous nephropathy. Some trials have shown that CsA may improve proteinuria and there is also some suggestion that the drug might protect against renal function deterioration. Thus, when given at correct doses, CsA may exert an anti-proteinuric effect without deteriorating renal function, suggesting that the drug may represent a further tool in treating the primary nephrotic syndrome.