To preserve patient privacy and for didactic purposes, case descriptions and pathology reports have been anonymized and partially fictionalized. The pathology images are representative images from a mixture of similar cases.

Invited Speakers

Stewart Lecker
Stewart LeckerCase Presenter | Beth Israel Deaconess Medical Center, Boston, MA, USA | No conflict of interest reported
Isaac Stillman
Isaac StillmanNephropathology Discussant | Beth Israel Deaconess Medical Center, Boston, MA, USA | No conflicts of interest reported
Adam Segal
Adam SegalNephrology Discussant | Beth Israel Deaconess Medical Center, Boston, MA, USA | No conflict of interest reported

Case

Patient is a 43-year-old female with underlying Sjogren’s syndrome and Postural Orthostatic Tachycardia Syndrome (POTS).  As part of her routine follow up by primary care physician and rheumatologist, she was found to have increasing proteinuria. This was considered to be quite unusual as her POTS and Sjogren’s syndrome have both been stable and are typically not associated with glomerular pathology.

Over the subsequent several months her proteinuria increased to over 2 g/g creatinine and microscopic hematuria developed. ANCA titer was checked and was positive (pANCA 1:320, quantitation >800).  Given her subtle disease (biopsy below) and normal kidney function, it was quite an unusual presentation for ANCA-associated vasculitis.  She had been on allopurinol for gout, which was changed to febuxostat.

Medical history:
Cataract
Allergic rhinitis
Gout

Medications:
Loratadine PRN
Febuxostat

Physical Exam:
Well appearing woman, without edema, rash, or other focal findings

Laboratory and other data:
Baseline creatinine 0.8 – 0.9
pANCA 1:320 (anti-MPO)
ANA 1:160
dsDNA neg, complements normal
Urinary protein to creatinine ratio 2.4 gram

Short term follow up:
Patient was given 4 doses of rituximab and CD20 repopulated 5 months later.
Kidney function has remained normal (creatinine 1.16 mg/dl, same as at rituximab initiation, but slightly higher than the previous baseline of 0.8-0.9 a year ago).
Proteinuria persists (peak 2.4g/g 6 months ago, 1.9g/g now), microhematuria unchanged, ANCA hasn’t disappeared but has improved (1:160).

Kidney Pathology

Pathology images pending

Renal biopsy showed focal sclerosis, with a couple of minute areas of focal necrosis.

Questions posed & summary of key discussion points

1. Does the patient have an ANCA-associated disease?
2. The biopsy was pretty atypical. Do you think the FSGS was a manifestation of percolating ANCA disease?
3. What treatment, if any would you have embarked on after the biopsy results?
4. What would you do now in terms of treatment? Her CD20+ lineages are back, and the MPO-ANCA persists, though less. No evidence that her renal manifestations are any better or worse?

Author(s) of case summary:

Case summary pending

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