A case of ANCA-associated glomerulonephritis without extrarenal symptoms with disease flare after starting dialysis

A Japanese girl aged 13 years with myeloperoxidase anti-neutrophil cytoplasmic antibodies(MPO-ANCA)-associated glomerulonephritis(GN) progressed to end-stage renal failure after 7 years' clinical observation. She had been suffering from recurrent disease flare associated with serum MPO-ANCA elevation(i.e. 153 EU/ml, 208 EU/ml and 358 EU/ml, maximum at each of the episodes, normal < 10 EU/ml). Each flare was treated successfully with prednisolone combined with cyclophosphamide and azathioprine. However, her renal function gradually deteriorated, and peritoneal dialysis(PD) was initiated 7 years after the onset of the disease. During the clinical course, no extrarenal manifestations were observed. Due to subsidence of the serum MPO-ANCA titer(10 EU/ml) after starting PD, prednisolone and azathioprine were tapered thereafter. Her daily urine volume was preserved at approximately 600 ml at that time. She suddenly developed fatigue with severe anemia, oliguria and hypertension 4 months after discontinuation of immunosuppressive therapy. The serum titer of MPO-ANCA increased to 100 EU/ml. These clinical observation suggests that disease flare may occur in selected patients with MPO-ANCA-associated GN, who develop end-stage renal failure requiring PD. Although recurrent flare associated with an increased serological activity in a proportion of patients with lupus nephritis who have received dialysis has been reported to date, to our knowledge, a similar clinical observation in the MPO-ANCA-associated GN has not been reported. Selected patients with the disease should be followed with close observation after undergoing dialysis.