A case of chronic relapsing ANCA-associated microscopic polyangiitis successfully treated with plasma exchange.

We report the case of a 4.5-year-old girl with microscopic polyangiitis (MPA) manifesting antineutrophil cytoplasmic autoantibody (ANCA)-positive necrotizing crescentic glomerulonephritis and pulmonary hemorrhage. She was initially on induction therapy with corticosteroids and azathioprine. Plasma exchange (PE) combined with immunosuppressants was used to treat an episode of recurrent pulmonary hemorrhage, and achieved remission. At 9.8 years of age her kidney disease relapsed, associated with renal dysfunction and increased proteinuria. To minimize the toxic effects of immunosuppressants, she was treated with PE again, and her renal dysfunction resolved. Plasma exchange was effective in reducing the risk of death and preserving long-term renal function without the severe adverse effects of immunosuppressants. Our preliminary results indicate that PE is likely to be a treatment option for children in acute phase of ANCA-associated MPA, who should be protected from the toxic effects of immunosuppressants.