ANCA-negative idiopathic pulmonary fibrosis developed into ANCA-positive rapidly progressive glomerulonephritis after 12 years follow up

摘要

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrotic disorder of the lung parenchyma. Rapidly progressive glomerulonephritis (RPGN) is a disease characterized by acute loss of renal function with glomerulonephritis, which is diagnosed by a pathologic pattern of crescent formation. A subgroup of RPGN is associated with anti-neutrophil cytoplasmic antibodies (ANCA). ANCA are abnormal auto-antibodies which are particularly related to small-vessel vasculitis in the kidneys. The perinuclear (p-ANCA) and cytoplasmic (c-ANCA) immunofluorescent patterns mainly correspond to antibodies directed against myeloperoxidase (MPO) and proteinase-3 (PR3), respectively. Herein, we report a case of a 37-year-old man with a history of ANCA (?) IPF who abruptly developed ANCA (+) RPGN with pulmonary renal syndrome after 12.5 years.