Biotin 5000mcg has not been shown to directly cause kidney damage when taken as a supplement. However, if you have IgAN you should:

Tell your doctor you're taking it, as biotin can interfere with some lab test results
Start with a lower dose (around 1000mcg) and monitor how you feel
Check with your nephrologist before starting, as they know your specific kidney function
The main concern with biotin isn't kidney damage, but rather ensuring it doesn't interact with your other IgAN medications or treatments.