A case of posterior and reversible encephalopathy syndrome in a patient previously undiagnosed with lupus nephritis.

Posterior reversible encephalopathy syndrome (PRES) is a rare clinico-neuroradiologic disease associated with various conditions, such as hypertension, eclampsia, chronic kidney disease, and autoimmune diseases. Here, we present the case of the unusual occurrence of PRES with hypertensive emergency and renal insufficiency in a 37-year-old woman previously undiagnosed with systemic lupus erythematosus (SLE) and lupus nephritis. The patient was emergently admitted to our hospital with sudden onset of visual impairment, headache, and high blood pressure, and she was eventually diagnosed with PRES by brain magnetic resonance imaging (MRI). Her PRES-associated clinical symptoms and MRI abnormalities were improved following anti-hypertensive treatment with calcium channel blocker. A kidney biopsy revealed diffuse proliferative glomerulonephritis with a full-house immunofluorescence pattern and fibrinoid necrosis in small blood vessels, suggesting a class IV-G (A) lupus nephritis with vasculitis. The immunosuppressive therapy with intravenous methylprednisolone pulse followed by oral prednisolone, mycophenolate mofetil, and intravenous belimumab, attenuated SLE-associated clinical manifestations including butterfly rush, edema, renal dysfunction, and proteinuria. Our case highlights the need to consider PRES as an initial clinical presentation of lupus nephritis and provide the early diagnosis and timely treatment to achieve a favorable outcome.