Abstract: FR-PO936
Urinary White Blood Cell Casts Suggest Presence of Crescentic Lesions in Acute Glomerulonephritis
Session Information
- Glomerular Diseases: Potpourri
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Mohamed, Muner, Ochsner Health, New Orleans, Louisiana, United States
- Mohammed, Khalid M.G, Tanta University, Tanta, Gharbia, Egypt
- Chalmers, Dustin R., Louisiana State University, Baton Rouge, Louisiana, United States
- Varghese, Vipin, University of Michigan, Ann Arbor, Michigan, United States
- Kanduri, Swetha Rani, Ochsner Health, New Orleans, Louisiana, United States
- Velez, Juan Carlos Q., Ochsner Health, New Orleans, Louisiana, United States
Group or Team Name
- Ochsner Group.
Background
Unlike standard dogma of their association with acute interstitial nephritis, urinary white blood cell casts (uWBCC) are more commonly detected in cases of acute glomerulonephritis (GN). However, granular aspects of this association have not been explored. We hypothesized that uWBCC may correlate with specific morphological histopathological findings in GN.
Methods
We prospectively collected data of patients seen in nephrology consultation who had a urine specimen subjected to microscopic examination of the urinary sediment (uSEDI) as part of the clinical evaluation. Within this cohort, we identified cases in which a kidney biopsy was performed and a diagnosis of GN was made. We assessed the performance of uWBCC in predicting specific lesions in GN: cresentic/necrotizing (Cresc/Necr) lesions, endocapillary proliferation (EC) or intersitial inflammatory inflitrate (III).
Results
Among 801 patients assessed by uSEDI over a 5-year period, 107 (15%) had biopsy-proven GN. Within that group, 24 (22%) had uWBCC. Mean age was 54 years, 51% women, 50% white and 38% black. Median serum creatinine at diagnosis was 3.6 (0.7-15.6) mg/dL. Biopsy diagnosis was pauci immune GN in 6 (25%), IgA nephropathy in 6 (25%), lupus GN in 3 (13%) and other proliferative or infection-related GN in 9 (37%). The sensitivity (SENS), specificity (SPEC), positive predictive value (PPV) and negative predictive value (NPV) of uWBCC for identifying Cresc/Necr lesions were 34%, 90%, 71% and 28%, respectively, whereas the SENS, SPEC, PPV and NPV of uWBCC for identifying EC were 28%, 80%. 38% and 27%. Also, the SENS, SPEC, PPV and NPV of uWBCC for III were 75%, 48%, 38% and 96%. Notably, 6 out of 9 GN cases with uWBCC and III also had Cresc/Necr lesions.
Conclusion
Identification of uWBCC by uSEDI in patients GN is fairly specific to predict Cresc/Necr lesions. This observation suggests that WBCs contained in casts likely originate from circulating cells that travel from the glomerular capillary lumen into the Bowman space through glomerular basement membrane (GBM) breaks. In addtion, absence of uWBCC is highly predictive of absence of III. These findings offer diagnostic/therapeutic insight for the clinician in anticipation of a kidney biopsy.