Is it true that elevated uric acid and gout can raise creatinine level? my nephro doctor told me so.

Yes: It is called a gouty nephropathy and is caused by the deposition of uric acid crystals in the kidney. It is the results of longstanding uncontrolled gout.

Yes: This happens when crystals of uric acid form in the kidney parenchyma -- "urate ephropathy". There is a severe acute form that is unmistakable; there's disagreement as to whether mild elevations of uric acid do this -- i'm a pathologist interested in kidney and haven't seen anatomic evidence that it's so. Consider adding a uric-acid lowering agent if you have clinical gout.