[Study on a predictive marker for evaluating the effectiveness of steroid therapy in IgA nephropathy-significance of...

In order to obtain a useful index that can predict the effectiveness of steroid therapy in IgA nephropathy, we investigated the relationship between steroid therapy and extracapillary change. We analysed 51 cases consisting of a group of 24 cases in which steroid was administered (initial dose: prednisolone 20-60 mg/day orally, or pulse therapy), and a group of 27 cases in which steroid was not administered. First of all, we compared these two groups in terms of a clinical improvement rate over 3, 12 and 60-month-periods after the therapy, respectively. It was found that steroid therapy led to a higher improvement rate (p < 0.01-0.05), indicating that steroid is effective for IgA nephropathy. Among the group undergoing steroid therapy, the frequency of cellular crescents (C) was significantly higher (p < 0.05-0.01) in the cases in whom steroid was effective and that of fibrous crescents or adhesion (F) was significantly lower (p < 0.05-0.01). We then assessed C/F in each case of the steroid-administered group, and studied its relationship with the improvement rate. As a result, the improvement rate was below 50% in the group of C/F < 0.25, over 50% of the group of 0.25 < or = C/F < 0.75, and 100% of the group of 0.75 < or = C/F. Accordingly, we concluded that C/F could be used a parameter for predicting the effectiveness of steroid therapy in IgA nephropathy and for determining indications for steroid therapy.