Treatment of corticoresistant idiopathic nephrotic syndrome in the adult: minimal change disease and focal segmental glomerulosclerosis

Abstract

We undertook a review of the literature concerning idiopathic NS in the adult (with MGL or due to FSGS) in an effort to assess the results obtained with corticosteroid and/or conventional immunosuppressive treatments. We found few usable published works and we were left with an impression of great imprecision. This imprecision stems both from frequently deficient definition of glomerular lesions and from different evaluations of responses to treatment. The almost total absence of controlled series, due to the rarity of nephrosis in the adult, hinders any firm conclusions with regard to the effect of treatments. It limits evaluation to mere tendencies, formulated in such vague terms as "complete remission," "partial remission," and "treatment failure," in a disease whose natural history is sometimes so whimsical that the same clinical case, over a period of years, can be both a success and a failure of the same treatment. In the adult, there is a significant difference in the incidence of complete remissions obtained by corticosteroids according to whether the NS is due to MGL or to FSGS. Nevertheless, the published data are difficult to interpret because dosage and length of treatment vary among authors. A high percentage of corticoresistant, corticodependent, or multirelapsing nephroses responds to immunosuppressive treatment. Efficacy has been documented for three drugs. Chlorambucil is easy to use but entails some long-term oncogenic hazards. Cyclophosphamide has more short-term side effects, but its long-term risk of malignancy appears less. Both of these alkylating agents may definitively compromise fertility. Azathioprine, easy to use but prescribed surprisingly little in NS, may have considerable advantages over alkylating drugs, which would justify reconsidering its use in nephrosis. An open, cooperative study was launched to determine the efficacy and the tolerance of cyclosporine in 45 patients who had been considered as failures of corticosteroid and/or conventional immunosuppressive therapy. The preliminary results of this trial showed that two thirds of the patients with cases of MGL and half of those with FSGS had total or partial remission after long-term treatment with cyclosporine. It is not yet known whether this may eventually lead to lasting remission after treatment is progressively tapered to a stop, or only represent reappearance of low-dose corticosensitivity. In case of dependence on this new immunosuppressive drug, long-term tolerance remains to be determined.(ABSTRACT TRUNCATED AT 400 WORDS)