Abstract: FR-PO635
Urinary White Blood Cell Casts Are Commonly Associated With Glomerulonephritis Rather Than Acute Interstitial Nephritis
Session Information
- Glomerular Diseases: Clinical, Outcomes, Trials - II
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1303 Glomerular Diseases: Clinical‚ Outcomes‚ and Trials
Authors
- Chalmers, Dustin, Department of Nephrology, Ochsner Health, New Orleans, Louisiana, United States
- Kanduri, Swetha Rani, Department of Nephrology, Ochsner Health, New Orleans, Louisiana, United States
- Varghese, Vipin, Department of Nephrology, Ochsner Health, New Orleans, Louisiana, United States
- Seltzer, Jay R., Missouri Baptist Medical Center, St. Louis, Missouri, United States
- Velez, Juan Carlos Q., Department of Nephrology, Ochsner Health, New Orleans, Louisiana, United States
Group or Team Name
- Ochsner Nephrology
Background
Urinary white blood cell casts (uWBCC) are traditionally thought to be indicative of acute interstitial nephritis (AIN). However, clinical data supporting this contention is lacking. uWBCC has also been described in glomerulonephritis (GN) and pyelonephritis (PN). Herein, we investigated the diagnostic performance of uWBCC in differentiating the etiology of kidney disease.
Methods
We prospectively collected data of patients seen in nephrology consultation who had a urine specimen subjected to microscopic examination of the urinary sediment (MicrExUrSed) as part of the clinical evaluation. Within this cohort, we identified cases in which a kidney biopsy was performed. We assessed the performance of uWBCC in the diagnosis of GN and AIN. To specifically assess for immune-mediated and/or proliferative GN (uWBCC are plausible), podocytopathies (e.g., collapsing glomerulopathy, diabetic nephropathy) were grouped separately. In addition, we pooled cases in which uWBCC were identified, with and without kidney biopsy confirmation, at our site and at an additional contributing site where MicrExUrSed is routinely performed.
Results
Among 683 patients with MicrExUrSed,103 (15%) underwent kidney biopsy and were included. Mean age was 55 years, 51% women, 50% white and 38% self-identified black. Median serum creatinine was 3.4 (0-7-15.6) mg/dL. Biopsy diagnosis was GN in 42 (41%) and non-GN in 61 cases (59%). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of uWBCC for diagnosis of GN were 26%, 85%, 55% and 62%, respectively, whereas the sensitivity, specificity, PPV and NPV of uWBCC for diagnosis of AIN were 8%, 79%. 5% and 87%. Thus, the PPV of uWBCC to diagnose GN was greater than that for AIN. In addition, out of 37 cases total with uWBCC, 27 (73%) had GN [16 (59%) of them with acanthocytes also present], 3 (8%) had PN, 6 (16%) had others and only 1 (3%) had AIN, further substantiating the observation that uWBCC are more likely to be associated with GN.
Conclusion
Identification of uWBCC predominantly reflected a diagnosis of GN rather than AIN. This finding challenges the current paradigm, traditional teaching, and standardized testing on this topic, all of which should be revisited.