Late restoration of renal function in patients with severe ANCA-associated glomerulonephritis who were dialysis-dependent at presentation

In antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), many patients with severe renal dysfunction are on dialysis at presentation. Among those who got rid of dialysis finally, renal restoration happened mostly within the first 3 months of treatment. However, in clinical practice, we occasionally encountered patients who got rid of dialysis after 3 months. The current study investigated clinical and pathological features of AAV patients with so-called delayed renal function restoration. A total of 156 patients with ANCA-associated glomerulonephritis who were on dialysis at presentation were retrospectively recruited. Clinical and pathological data as well as treatment and outcomes were analyzed. Among these 156 patients, 58 and 12 patients got rid of dialysis within and after 3 months, respectively. Among the 12 patients with delayed renal function restoration, 8 and 4 patients got rid of dialysis within and after 6 months, respectively. Among the 72 patients who were still on dialysis at the end of 3 months since the initiation of immunosuppressive therapy, those receiving intravenous cyclophosphamide therapy over 3 months had significantly higher proportion of renal function restoration than those receiving intravenous cyclophosphamide for only 3 months (8/14 versus 4/58, P < 0.001). For patients with ANCA-associated glomerulonephritis who were on dialysis at presentation, there is an unnegligible proportion of patients who had their renal function restoration beyond 3 months since the initiation of immunosuppressive therapy. Further studies are needed to investigate whether, and for whom, cyclophosphamide prescription should be prolonged for more than 3 months.