Abstract: PO2397
Class II Donor-Specific Anti-HLA Antibody Level Is the Major Determinant of Elevated Donor-Derived Cell-Free DNA in Renal Allograft Recipients
Session Information
- Clinical and Immunologic Predictors of Post-Transplant Outcomes
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 1902 Transplantation: Clinical
Authors
- Butiu, Maria, University of Washington, Seattle, Washington, United States
- Obrisca, Bogdan, Fundeni Clinical Institute, Bucharest, Romania
- Bakthavatsalam, Ramasamy, University of Washington, Seattle, Washington, United States
- Smith, Kelly D., University of Washington, Seattle, Washington, United States
- De Castro, Iris C., University of Washington, Seattle, Washington, United States
- Blosser, Christopher D., University of Washington, Seattle, Washington, United States
- Sibulesky, Lena, University of Washington, Seattle, Washington, United States
- Kling, Catherine, University of Washington, Seattle, Washington, United States
- Ismail, Gener, Fundeni Clinical Institute, Bucharest, Romania
- Sorohan, Bogdan Marian, Fundeni Clinical Institute, Bucharest, Romania
- Leca, Nicolae, University of Washington, Seattle, Washington, United States
Background
Dd-cfDNA is a biomarker of allograft injury used for rejection risk monitoring. We sought to analyze the relationship between dd-cfDNA and DSA.
Methods
We included all kidney transplant recipients (n=171) who underwent DSA and dd-cfDNA testing as part of their clinical care between 9/17-12/19 at our center. We aimed to identify independent predictors of high dd-cfDNA (at a cut-off of 1%).
Results
Table 1 outlines clinical characteristics. There was a strong association between absolute dd-cfDNA level and DSA MFI category (Figure 1). In multivariate logistic regression analysis, DSA MFI was an independent predictor of high dd-cfDNA (Figure 2).
Conclusion
Dd-cfDNA is strongly associated with class II DSAs and MFI level. Variability observed identifies dd-cfDNA as a potential biomarker for monitoring allograft injury status in patients with DSA.
Clinical Characteristics
| Low dd-cfDNA <1% | High dd-cfDNA >1% | p value | |
| Number of subjects | 139 | 32 | |
| Creatinine (mg/dl) | 1.54±0.52 | 1.41±0.51 | 0.18 |
| No DSA | 114 (82%) | 14(44%) | <0.001 |
| Class I DSA | 4(3%) | 1(3%) | |
| Class II DSA | 20(14.4%) | 15(46.9%) | |
| Class I+II DSA | 1(0.7%) | 2(6.2%) | |
| DSA MFI(median) | 2900 | 13200 |
Donor-derived cell-free DNA level by presence and titer of DSAs
Binary logistic regression analysis regarding variables associated with a high dd-cfDNA level (>1%)
Funding
- Commercial Support – CareDx Inc