Abstract: PUB015
Not All Cases of Tubulointerstitial Nephritis Are the Same
Session Information
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Aguilar Bolona, Carlos Emilio, Baylor College of Medicine, Houston, Texas, United States
- Kassem, Hania, Baylor College of Medicine, Houston, Texas, United States
- Tchakarov, Amanda, The University of Texas Health Science Center at Houston Department of Pathology and Laboratory Medicine, Houston, Texas, United States
Introduction
Acute tubulointerstitial nephriti (TIN) is a common cause of AKI. Approximately 70% of cases are linked to exposure to drugs. Infections can also cause acute TIN.
We present a case of a 65-year-old female with an unusual case of pyelonephritis induced TIN.
Case Description
Patient presented to the hospital with abdominal pain and fever. She has a history of type 2 DM, polycythemia vera, myelofibrosis on ruxolitinib, and coronary artery disease. Prior to admission, she was treated with antibiotics on two occasions for pyelonephritis. Upon presentation, patient had a WBC of 34 K/µL, and a Cr of 1.3 (baseline 0.9-1). CT showed perinephric stranding, and multiple consolidations at the lung bases. She was started on vancomycin and cefepime with subsequent improvement.
Approximately 10 days after admission, her Cr started up-trending. Initial workup with a UA showed microscopic hematuria, pyuria, and sub-nephrotic range proteinuria. One of three urine cultures was positive for 1.000-10.000 CFU of Candida albicans. The other two cultures were negative. Despite her clinical improvement, her renal function continued to worsen, peaking at 6.5.
With concerns for TIN, she was started on empiric prednisone and a kidney biopsy was performed. Pathology reported a neutrophil predominant TIN with peritubular neutrophilic cuffing along with tubular and interstitial micro-abscess formation, consistent with pyelonephritis. Patient was discharged on Levofloxacin, with close follow up planned. A few weeks later, she presented to a different hospital with similar symptoms. Her Cr on admission was 6.1 mg/dL. She was started on broad spectrum antibiotics and on fluconazole. Her Cr improved and patient was discharged 5 days later with a Cr of 2.7.
Discussion
In patients with TIN, bacterial, viral, and fungal etiologies must be considered. In this case, multiple urine cultures were performed, with only one being positive for Candida albicans, a finding that was not initally thought to be relevant.
Our patient was exposed to multiple courses of antibiotics. She improved clinically with treatment, but her renal function worsened. Initially we had concerns about drug related TIN, but with the kidney biopsy results, her history of immunosuppression (myelofibrosis, JAK inhibitor), and her renal function improving after treatment with fluconazole, we reached the diagnosis of fungal pyelonephritis causing acute TIN.