23rd June 2023

A 69-year-old man is admitted to hospital, unwell and febrile.

A 69-year-old man is admitted to hospital, unwell and febrile. He is noted to have a pansystolic murmur at the cardiac apex and a subsequent echocardiogram confirms vegetations on the mitral valve. He grows a staphylococcus aureus in three blood cultures and is started on appropriate intravenous antibiotics.

He is noted to have an acute kidney injury on admission, with a serum creatinine of 210μmol/L from a baseline of 75μmol/L (normal range 60-100μmol/L). Further investigations show blood and protein on a urine dip and low serum complement levels.

What is the most likely cause of the renal impairment?