Background: Cyclosporin has improved the outcome for steroid-resistant patients with focal glomerulosclerosis, but there is a proportion of patients that are either cyclosporin-resistant or suffer relapses, needing long-term therapy to sustain the remission. In these cases, preliminary reports suggest that tacrolimus could be an alternative therapy, but to date the evidence is limited to small series of patients with no long-term follow-up.
Methods: In this study we analysed the efficacy and safety of a combined therapy of tacrolimus and steroids in 25 patients (mean serum creatinine= 1.24+/-0.49 mg/dl; mean proteinuria=10.2+/-9.5 g/day; mean serum albumin=2.4+/-0.58 g/dl) with idiopathic primary focal glomerulosclerosis and proven resistance to or dependence on cyclosporin A.
Results: After a 6 months trial of tacrolimus and steroids, proteinuria decreased in 17 patients (68%) (complete remission in 10 patients (40%), partial remission in two patients (8%) and a moderate reduction in proteinuria to levels <3 g/day was seen in five additional patients (20%)). The only predictor of response to tacrolimus was a previous response to cyclosporin and prednisone, either as a complete or partial remission (remission rate 75% vs 15.3; P=0.036). Mean time to remission was 112+/-24 days. After tacrolimus discontinuation, 13/17 patients (76%) relapsed and were treated with a second trial of tacrolimus for 1 year, achieving complete remission in five patients (38.4%), partial remission in four patients (30.7%) and reduction of proteinuria <3 g/day in four patients (30.7%). After 2 years of follow-up, 12 patients (48%) were on sustained remission. The main side effect was acute reversible nephrotoxicity (40%). Predictors of renal toxicity were age (P=0.037), baseline creatinine (P=0.046) and tacrolimus trough level (P=0.001).
Conclusions: We conclude that combined therapy of tacrolimus and steroids induce sustained remission of proteinuria in a significant number of patients with idiopathic focal glomerulosclerosis whose disease was not controlled by the standard therapy of steroids and cyclosporin A.