Abstract: SA-PO058
A Case of Tubulointerstitial Nephritis and Uveitis With Fanconi Features
Session Information
- AKI: Important, Yet Underappreciated Causes
November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical‚ Outcomes‚ and Trials
Authors
- Liu, Andrew Chi-Yeu, University of California San Diego, La Jolla, California, United States
- Zhang, Haiyan, University of California San Diego, La Jolla, California, United States
- Malhotra, Rakesh, University of California San Diego, La Jolla, California, United States
Introduction
Tubulointerstitial nephritis with uveitis (TINU) syndrome is an uncommon auto-immune disease with ocular-renal manifestations. Here we report a rare case of a patient with TINU and Fanconi features.
Case Description
A 20-year-old Chinese male presented with nasal congestion, myalgia and arthralgia for several months. He also complained of bilateral painful red eyes and photophobia. He had no significant medical history and was not taking any prior medications. Patient was seen by ophthalmology and was found to have bilateral posterior uveitis with no granuloma. His physical exam was otherwise normal. He was started on prednisone eye drops. Laboratory results showed increased inflammatory markers (ESR 42mm and CRP 0.57 mg/dL), renal dysfunction (serum creatinine 1.92 mg/dL) and anemia (Hgb 11.0 mg/dL). The chest radiography was normal. Serologies for syphilis, toxoplasmosis, hepatitis B and C, HIV, and tuberculin skin test were negative. No auto-immune marker (HLA-B27, complement C3 and C4, anti-nuclear antibody, and anti-neutrophil cytoplasmic antibody) was positive. Serum potassium, bicarbonate and glucose levels were normal. Whereas urine test showed glucosuria, proteinuria (0.5 g/g) and elevated beta-2 microglobulin (20649 ug/L). Fractional excretions for uric acid and phosphorous were elevated to 16% and 24% respectively. Renal biopsy showed severe diffuse interstitial inflammatory infiltrate with predominantly lymphocytes mixed with other inflammatory cells (Figure 1). No granuloma was identified. Severe tubulitis was present and immunofluorescence staining was negative for immunoglobulin, thus establishing the diagnosis of TINU with Fanconi like features. He was started on oral systemic steroids with improvement in kidney function.
Discussion
TINU is an immune-mediated process that involves autoantigens targeting renal interstitium and ocular cells. In cases of more severe tubulitis Fanconi syndrome may present. Future studies should report long-term renal outcomes, duration of steroid therapy and recurrence rates in patients with TINU and Fanconi syndrome.