Abstract: SA-PO676
Correlation of Papillary Grading and Metabolic Parameters in Calcium Stone Formers
Session Information
- Bone and Mineral Metabolism: Clinical - II
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 402 Bone and Mineral Metabolism: Clinical
Authors
- Zisman, Anna L., University of Chicago, Chicago, Illinois, United States
- Coe, Fredric L., University of Chicago, Chicago, Illinois, United States
- Worcester, Elaine M., University of Chicago, Chicago, Illinois, United States
Background
Papillary grading has emerged as a novel technique to standardize ureteroscopic findings, but its relationship to stone pathogenesis is poorly understood. As 24-hour urine metabolic risk parameters predict stone type and likelihood of recurrence, we sought to determine whether papillary grading correlates with these parameters.
Methods
Patients' endoscopic findings during stone procedures were graded by two urologists at a single academic institution using a previously described renal papillary grading system. This system quantifies the degree of Randall’s plaque (RP), pitting, plugging, and loss of contour, yielding a summary score for each papillum. Composite scores were generated by averaging all papillary scores from a single kidney. Patients were included if they had calcium based stones and completed two 24-hour urine collections with paired serum studies prior to treatment. Pearson correlations were used to determine relationships between individual components of the score, total score, and average across the categories as related to urinary metabolic risk factors.
Results
41 patients (43% Male, 63% Caucasian) were included. The mean age was 52.1 yrs (±7.5) and mean BMI was 30.8 (±4.0) kg/m2. Contour was inversely related to 24 hr urine calcium (P<0.05) and calcium phosphate supersaturation (SSCaP) (p<0.05). Pitting is directly related to 24-hr urine oxalate (p<0.05) and inversely related to urine volume (p<0.05) (Figure). No significant correlations were found for urine pH or 24 hr urine citrate. Significant differences in RP scores (AA 0.53, C 1.35, p<0.003), but not the other grading components, were noted across racial groups.
Conclusion
Papillary grading correlates with 24 hr urine volume, calcium, oxalate, and SSCaP. Racial differences in RP burden suggest differing mechanisms of calcium lithogenesis by race which warrants further study.
Funding
- NIDDK Support