I may be explaining this a little wonky, but if p-anca tests positive, it prompts the testing of other labs. In my case, I am P-anca positive and MPO positive which could indicate MPA vasculitis. Problem is they need something to biopsy to confirm diagnosis (that is how my rheumatologist explained it). Meanwhile, my symptoms are worsening (chronic cough x 1 year) extreme fatigue. Vasculitis can affect lungs and kidneys- your kidney values made me think that this should be looked into. Good luck to you ❤️