Anti-glomerular basement membrane antibody disease complicated by posterior reversible encephalopathy syndrome.

Anti-glomerular basement membrane (anti-GBM) antibody disease is a rare type of small-vessel vasculitis. Posterior reversible encephalopathy syndrome (PRES) is a syndrome of heterogeneous aetiologies grouped together based on similar neuroimaging findings. We report a rare case of a patient who received treatment for anti-GBM antibody disease who developed PRES. A 33-year-old woman presented with severe generalised oedema, proteinuria, haematuria, and cylindruria. She was diagnosed with anti-GBM antibody disease based on positive findings for anti-GBM antibodies and urinalysis. Haemodialysis was eventually required. She received steroid therapy, plasma exchange therapy, and intravenous cyclophosphamide, along with a red blood cell transfusion for progressive anaemia. After the transfusion, she experienced nausea, severe headache, visual hallucinations, and agitation followed by seizures and a rapid increase in blood pressure. Imaging studies led to a diagnosis of PRES. Renal failure improved with the decrease in anti-GBM antibodies, and haemodialysis was discontinued. Phenytoin was administered, and seizures disappeared. Although we cannot rule out the possibility that the treatment this patient underwent for anti-GBM antibody disease led to the development of PRES, we speculate that endothelial dysfunction leading to the development of PRES is caused not only by known risk factors such as cytotoxic agents, blood transfusions, or renal failure, but also by immunological abnormalities and subsequent inflammatory reactions due to anti-GBM antibody disease. These factors may be shared pathophysiologic mechanisms of PRES and anti-GBM antibody disease.