[Case of immune complex crescentic glomerulonephritis with consistently high titers of MPO-ANCA for 6 years].

A male patient, now 65 years old, experienced fever, hemoptysis, and respiratory failure about six years ago. Soon thereafter, he developed rapid progressive renal dysfunction with pulmonary hemorrhage and positive findings for MPO-ANCA. We commenced methylprednisolone pulse (MP) therapy followed by oral prednisolone (PSL) and intravenous cyclophosphamide (CY) for the treatment of ANCA-associated microscopic polyangiitis (MPA).