MRCP2-3575
A 50 year-old man presents to the nephrologists with chronic kidney disease. He has a medical history of hypertension, type 2 diabetes, and Parkinson’s disease, and is currently taking ramipril, metformin, and bromocriptine.
Over the past year, his glomerular filtration rate (GFR) has steadily declined from 85 to 44 ml/min/1.73m². The only symptom he reports is chronic back pain, which has been worsening over the same period. On examination, both kidneys are palpable.
Routine investigations reveal the following results:
– Hb: 12.1 g/dl
– MCV: 94.2 fl
– Platelets: 264 x10^9/l
– WCC: 7.1 x10^9/l
– Na: 137 mmol/l
– K: 4.6 mmol/l
– Urea: 13.8 mmol/l
– Creatinine: 157 mol/l
– eGFR: 44 ml/min/1.73m²
– ALT: 24 IU/l
– ALP: 78 IU/l
– Bilirubin: 6 mol/l
– Albumin: 37 g/l
– Total protein: 64 g/l
– Serum protein electrophoresis pending
– Urine dipstick negative for blood, protein, leucocytes, and nitrites
An abdominal ultrasound reveals bilateral hydronephrosis. What is the most likely cause of his chronic kidney disease?