What Do Elevated Creatinine Levels When Diagnosed With Pyelonephritis Indicate?

My aunt is currently 60 years old and has been a diabetic for the last 17 years. Recently in May 2017, a simple UTI led to an AKI. The cause was diagnosed as pylo nephritis. There was no urine output for a week. After administering IV antibiotics, urine output was back to normal. Ser. creatinine was 5.1. She was put on dialysis every other day until June end. She was also given Wysolone 30-40 mg for a few weeks when the creatinine stabilized at 3.7. Alongside TB medicine was also given for 3 months until mid Oct to remove any bacterial presence. At this time, her creatinine is at 4.7 and urea 170. All other electrolytes/potssium, etc are normal. Are there any chances of this being a delayed recovery?