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.