Corticosteroids and mycophenolic acid analogues in immunoglobulin A nephropathy with progressive decline in kidney function

Background A randomized controlled trial demonstrated a beneficial effect of corticosteroids (CS) + cyclophosphamide followed by azathioprine in progressive immunoglobulin A nephropathy (IgAN). Although treatment with CS and mycophenolic acid analogues (MPAAs) remains controversial in IgAN, there is no information about their effects in progressive IgAN. Methods Patients with progressive IgAN, defined by a decrease in estimated glomerular filtration rate (eGFR) of at least 10 mL/min/1.73 m(2) in the 12 months prior to the start of treatment, proteinuria >= 0.75 g/24 h despite maximum tolerated doses of renin-angiotensin system blockers, and persistent haematuria who had received treatment with CS + MPAA were included in this retrospective study. The main outcome was the difference between the eGFR slope from the start of treatment with CS + MPAA to the last visit with this treatment with respect to the eGFR slope during the 12 months prior to the start of treatment. Results A total of 25 patients were included in the study. The mean duration of CS + MPAA treatment was 24.7 +/- 15.2 months. In the 12 months prior to treatment the median rate of kidney function decline was 23 mL/min/1.73 m(2)/year [interquartile range (IQR) -32 to -16]. After the onset of treatment, the median eGFR slope was 5 mL/min/1.73 m(2)/year (IQR 3-9; P = 0.001 with respect to the 12 months prior to treatment). Proteinuria decreased from 1.8 g/day (IQR 1.0-2.5) at baseline to 0.6 g/day (IQR 0.3-1.2) at the end of treatment (P = 0.01) and haematuria disappeared in 40% of patients. There were no serious adverse effects requiring treatment discontinuation. Conclusions CS + MPAA is an effective treatment in IgAN patients with a sustained decline in kidney function accompanied by persistent proteinuria and haematuria despite optimized conservative treatment. Prospective studies are needed to confirm these results.