MRCP-0581

A 28 year old female presents to her GP with joint pain , fever, a butterfly rash and fatigue. She has marked peripheral oedema. She is found to be hypertensive, in acute renal failure, low albumin levels and proteinuria. A renal biopsy is performed and reveals focal glomerulonephritis with subendothelial and mesangial immune deposits. What is the most likely diagnosis?