Long-term follow-up of patients with IgA nephropathy treated with prednisolone and cyclophosphamide therapy.

BACKGROUND: Analyses of selected cases suggest that immunosuppressive treatment could reduce proteinuria and delay the progression of immunoglobulin A nephropathy (IgAN). The aim of this study was to examine the long-term effectiveness of this therapy on the clinical course of IgAN. We also examined the relationship between the efficacy of the treatment and the suppression of the serum immunoglobulin level.

METHODS: Eighteen patients who were observed for more than 2 years after prednisolone and cyclophosphamide therapy were enrolled in this study. Their clinical and laboratory characteristics were recorded for 2-18 years (mean 7.8 +/- 5.7 years).

RESULTS: Of the 18 patients, 13 had remission of proteinuria. We observed the subsequent development of proteinuria in four patients. Fourteen patients had remission of hematuria, with five patients experiencing subsequent relapse of hematuria. The mean time from the treatment to the relapse of proteinuria or hematuria was 5.8 years. Serum immunoglobulins were suppressed by the combination therapy. Serum IgG and IgM recovered 6 months after the treatment, whilst the suppression of serum IgA lasted for 4 years. We found a positive correlation between the serum IgA level and the degree of proteinuria.

CONCLUSION: This study indicates that long-term follow-up is essential in order to prove the long-term benefit of immunosuppressive therapy in patients with IgAN. Careful monitoring of the serum IgA level may be useful in the follow-up of patients with IgAN, especially when they are treated with immunosuppressive agents.