a 63-year-old man
Overlap of PR3-ANCA-associated vasculitis and primary focal segmental glomerulosclerosis (FSGS)
He was given pulse methylprednisolone into the vein, then prednisone pills and rituximab to control the vasculitis. Because his nephrotic syndrome kept going, doctors added a calcineurin inhibitor, first cyclosporine and then tacrolimus, for the steroid-resistant FSGS. They also used renin-angiotensin system blockers, an SGLT2 inhibitor, and later a nonsteroidal mineralocorticoid blocker to lower protein in the urine. His protein loss started at 8.25 grams a day. He reached partial remission and his PR3 antibodies became undetectable.
A 63-year-old man with two kidney diseases at once, PR3-ANCA vasculitis and steroid-resistant FSGS, reached partial remission after a layered drug plan that treated each disease.
- Two different kidney diseases can rarely show up together, and this man had both PR3-ANCA vasculitis and primary FSGS confirmed by biopsy and blood tests.
- His kidney problem was severe at the start, with 8.25 grams of protein leaking into his urine each day, low blood protein, blood in the urine, acute kidney injury, and high blood pressure.
- The vasculitis was treated with pulse IV methylprednisolone, then oral prednisone and rituximab, while the FSGS needed a separate calcineurin inhibitor (cyclosporine, then tacrolimus) because it did not respond to steroids alone.
- Extra protein-lowering drugs were added on top: a renin-angiotensin system blocker, an SGLT2 inhibitor, and later a nonsteroidal mineralocorticoid blocker.
- In the end he reached partial remission, his nephrotic syndrome cleared, and his PR3 antibodies became undetectable.
Why it might work
The paper frames this as treating two separate problems with two separate strategies at the same time. The vasculitis is driven by an overactive immune system making PR3 antibodies that inflame the kidney's filters, so drugs like steroids and rituximab calm that immune attack and the antibodies fell to undetectable. The FSGS is scarring and damage to the filter cells (podocytes) that steroids did not fix, so a calcineurin inhibitor was added to protect those cells. On top of both, the RAS blocker, SGLT2 inhibitor, and mineralocorticoid blocker are used to lower the pressure and protein loss across the filters. Together these aimed at both the immune cause and the leaking filter.
The honest limits
- This is a single case report (n=1), so it cannot tell us how often this combination of drugs works for other people.
- The abstract reports partial remission, not full remission, and it does not give kidney function numbers like eGFR before or after.
- The follow-up is cut off in the abstract at 'After 2.', so we do not know how long the improvement lasted.
- The abstract does not state any conflicts of interest or funding, so those cannot be judged from what is shown here.
- If I had two kidney conditions at once, would each one need its own treatment, like it did in this case?
- For protein in my urine, could adding an SGLT2 inhibitor or a mineralocorticoid blocker to my current medicines help me?
- What does partial remission mean for my long-term kidney function, and how would you track it over time?