I biopsied an 80 year old lady with unexplained CKD (SCr 170) and active urinary sediment. Serology included a positive MPO ANCA. Biopsy shows no current activity on LM. IF is negative. There are no other systemic manifestations of vasculitis. What would you do?
I have had a few cases like this in older patients and have treated them more conservatively perhaps. I deferred typical induction therapy and placed them on imuran/prednisone. The difficulty of-course is deciding on an endpoint; the fibrous crescents might ultimately lead to obsolescent glomeruli or possibly recover- but in all likelihood, this could be her new baseline.
In the absence of ongoing inflammation with cellular crescents, it's hard to argue full scale induction treatment, especially since creatinine has stabilized and is systemically well.