ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

Abstract: TH-PO559

ANCA Vasculitis Presenting with Chronic Active Interstitial Nephritis Without Glomerular Involvement

Session Information

  • Trainee Case Reports - I
    October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Trainee Case Reports

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Plafkin, Callie, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
  • Singh, Tripti, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
Introduction

ANCA-associated vasculitis (AAV) with renal involvement typically causes pauci-immune glomerulonephritis. We present a rare case of chronic active interstitial nephritis as the sole renal lesion, without glomerulonephritis, in a patient with MPO AAV.

Case Description

A 45-year-old female with a history of Crohn’s disease, GERD with Barrett’s esophagus, endometriosis, and polyarthralgias was evaluated in nephrology clinic in 2018. Acute interstitial nephritis was initially diagnosed in 2011 on renal biopsy. There was no evidence of glomerulonephritis. p-ANCA was positive with MPO titer of >100 units/mL. She lacked systemic symptoms of AAV. Serum creatinine peaked at 2.1 mg/dL and improved to 0.9 mg/dL with prednisone and azathioprine. Repeat biopsy in 2013 for worsening renal function again showed acute interstitial nephritis and no vasculitic glomerular involvement. Prednisone and cyclosporine were started, with improvement in serum creatinine from 1.9 to 1.2-1.4 mg/dL. Crohn’s disease was diagnosed in 2014 and adalimumab was started in 2016. Acute interstitial nephritis was attributed to Crohn’s and cyclosporine was stopped in 2016. Her gastrointestinal symptoms improved with adalimumab, but renal function and abnormal urine sediment did not. Attempt was made to switch omeprazole to an H2-blocker but this was not tolerated. Repeat renal biopsy in 2/2018 showed chronic active interstitial nephritis with severe interstitial fibrosis and tubular atrophy and no active glomerular disease. MPO titers remained high at 132 units in 3/2018. She was started on mycophenolic acid and prednisone without significant response, followed by rituximab induction therapy for AAV-associated active interstitial nephritis. Serum creatinine continued to worsen to 5.5-5.7 mg/dL and preparations are being made to start peritoneal dialysis.

Discussion

AAV may present with isolated interstitial nephritis without glomerular involvement. The rarity of this presentation may contribute to delay in diagnosis and appropriate management. Alternate explanations for interstitial nephritis, such as Crohn’s disease or PPI use, should be considered with caution in the setting of high-titer ANCA positivity.