Sequential occurrence of anti-glomerular basement membrane disease 9 years after anti-neutrophil cytoplasmic antibody-associated vasculitis

We report a case of 63-year-old Chinese man, having a history of anti-myeloperoxidase (MPO) antibody anti-neutrophil cytoplasmic antibody (ANCA)-associated pulmonary-renal syndrome 9 years ago, presented with second episode of rapidly progressive glomerulonephritis (RPGN) and alveolar haemorrhage compatible with anti-glomerular basement membrane (GBM) disease. In first presentation, his anti-GBM antibody was negative. This time, anti-MPO antibody was negative, but anti-GBM antibody was positive. The long interval of sequential development of anti-GBM disease after ANCA-associated vasculitis in this patient may provide clues to the potential immunological links between these two distinct conditions. Clinicians should be aware of such double-positive association.