STEROID-THERAPY DURING THE EARLY-STAGE OF PROGRESSIVE IGA NEPHROPATHY- A 10-YEAR FOLLOW-UP-STUDY

This study was undertaken to clarify the effect of corticosteroids on the longterm clinical course of the early stage of progressive IgA nep hropathy. The early stage of progressive IgA nephropathy was defined a s having moderate proteinuria between 1 and 2 g/day, creatinine cleara nce values of 70 ml/min or more, and a histological severity score of 7 or more. The number of patients who fulfilled these three conditions during 12 years from 1972 and then were continuously followed up for 10 years or more in our renal unit was 46. Twenty of them received ste roid treatment for an average period of 18 months, and the remaining 2 6 patients had no steroid treatment. The initial data of proteinuria, creatinine clearance values, frequency of hypertensive cases, and hist ological scores of 7 or more were not different between the two groups : 1.4 +/- 0.4 vs. 1.3 +/- 0.3 g/day, 85 +/- 14 vs. 88 +/- 13 ml/min, 2 5 vs. 38%, and 10.7 +/- 2.5 vs. 11.0 +/- 3.0, respectively. During the follow-up period of 10 years, the renal survival rate was significant ly different between the two groups (100 vs. 84% 5 years after startin g therapy and 80 vs. 34% 10 years later; p < 0.001). The final creatin ine clearance values were significantly different between the two grou ps (54 +/- 35 vs. 20 +/- 29 ml/min; p < 0.005). On the other hand, the patient groups with mild histological changes or decreased renal func tion due to moderate proteinuria showed no significant differences in the final outcome. These results indicate that corticosteroids are ben eficial in stabilizing the renal function for a long time during the e arly stage of progressive IgA nephropathy, although this study was not a randomized one.