Serum or urine measure for CKD?

[userotc]

How can you judge progress with CKD if there appears to be conflict between serum and urine test results?

My mum has CKD stage 3 and had a cancerous kidney removed 3 years ago. Whilst her serum eGFR and creatinine results since then have been slowly improving (eGFR reached 61 ml/min 9 months ago and creatinine now down to 98 umol/l), urine tests a few days ago indicate the opposite. For example, her urine microalbumin has steadily risen to 43.3 ug/ml so is classified as abnormal.

Ive researched a few websites and they all indicate that both serum and urine results should be considered in combination eg: " combination of specific tests now called the Kidney Profile. When performed together, these tests—a urine sample for albumin-to-creatinine ratio (ACR) and a blood test for estimated glomerular filtration rate (eGFR)" bottomlineinc.com/health/ki.... But how is that possible if they indicate opposites?

She will ask her nephrologist when she sees him in ~2 weeks but hopefully you intelligent people can explain via knowledge and/or experience. Also she is not confident about her nephrologist, partly because he didnt raised urine results with her last year (abnormal/out of range then) and because he seems more focused on her cholestrol levels than her kidney results (my separate post yesterday)