<prompt> Least likely cause of renal papillary necrosis?Sickle cell diseaseAnalgesic nephropathyPosterior urethral valvesDiabetes with UTI  <response>: c. Posterior urethral valvesRef: Nelsons 20e p 2562-2567Ghai 8e p 485-486Sickle cell disease, use of analgesics and Diabetes are important causes of Renal papillary necrosis. 