IgA Nephropathy Is Not Terrible

Studies with the highest power and evidence levels include:
In 1999 Pozzi et al published a randomly assigned to supportive therapy only for additional corticosteroids. In a recently published, up to 10 years follow up of that population, serum creatinine had doubled in one of 43 patients in the steroid group versus 13 of 43 in the control group.
In 1999 Yoshikawa et al published a randomized controlled trial in Japanese children with normal GFR treated with supportive therapy or immunosuppression. During two years follow up proteinuria decreased from 1.0 to 0.9 in controls and from 1.4 to 0.2g/day in the immunosuppressed group. GFR remained normal in all but on child. Side effects in immunosuppressed children include growth retardation.
In 2000 Shoji published a randomized trial in which 8 patients were randomized to receive antiplatelet therapy only, while 11patienst receive additional oral prednisolone for one year. Proteinuria and histology were improved at one year in the steroid group. The study mainly dealt with low-risk patients.
In 2002 Ballardie et al published a randomized controlled single center study on IgA Nephropathy patients with progressive loss of renal function. Patients were randomized to prednisolone and cytotoxic agents or supportive therapy only. Renal survival in treated patients showed significantly better preservation of function at 5 years. 72% compared to 6% in controls. Morbidity attributable to treatment include one case of azathioprine-induced marrow suppression and one of secondary diabetes mellitus.
In 2003, Katafuchi et al published a randomized controlled trial in which 43 patients receive oral prednisolone as compared to 47 patients in the control group. Whereas renal survival was not improved by the steroid therapy, proteinuria decreased in the steroid group only. An unexplained, significantly higher baseline proteinuria in the steroid group considerable limits interpretation of this study.
In 2004, Maes et al described a prospective study in 34 patients with IgA Nephropathy and impaired renal function, who were randomized to 2g mycophenolate mefetil or placebo. After 3 years of follow up, insulin clearances and proteinuria did not different between the groups.