Abstract: PO2392
Donor Derived Cell-Free DNA in Renal Transplants, AlloSure vs. Prospera
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
- Khalil, Ali, Medical City Dallas Hospital, Dallas, Texas, United States
- Khan, Salman, Medical City Dallas Hospital, Dallas, Texas, United States
- Kalu, Erica, Dallas Nephrology Associates, Dallas, Texas, United States
- Saim, Muhammad, Medical City Dallas Hospital, Dallas, Texas, United States
- Lerman, Mark J., Medical City Dallas Hospital, Dallas, Texas, United States
Group or Team Name
- Medical City Dallas Kidney Transplant
Background
The risk for allograft loss remains high due to rejection. Measuring donor cell free DNA has recently become an important noninvasive test for renal allograft injury and rejection. Two of the commercially available tests to measure dd -cfDNA, are Allosure(AS) and Prospera.
Methods
We measured dd -cFDNA in 44 post kidney transplants simultaneously using both tests. Patients were 3 to 50 months post kidney transplant and all samples were drawn for cause. Eleven of the 44 patients had allograft biopsies, see table. All patients had routine labs including trough CNI levels and in some cases DSA and/or BK PCR.
Results
44 patients had side by side dd cf-DNA done using AS and Prospera for cause. There were 5 patients with either ACR 1a or 1b or AMR on biopsy. 6 patients had no rejection on biopsy. Please see image for statistical analysis.
Conclusion
There was no statistical difference between dd -cfDNA as measured by both commercial tests in all 44 patients , including 5 with ACR or AMR and 6 without rejection by biopsy. We acknowledge the number of patients who underwent biopsies were small. Prospera demonstated larger measurements of dd-cfDNA in comparison to AS ,but this was not statistically significant p=0.27. Side by side analysis showed AS had marginally better AUC but no significant differences between diagnostic test characteristics observed. AS had better specificity,PPV, and NPV, but this did not reach statistical significance.
Cell Free DNA in Patients with biopsy
| Sample | Prospera | Allosure | biopsy | creatinine | DSA |
| #3 | 1.07 | 0.96 | NEG | 1.37 | NA |
| #10 | 0.06 | 0.19 | NEG | 2.32 | NA |
| #12 | 5.86 | 4.6 | AMR | 1.5 | A24,DR4,DR53 |
| #16 | 0.66 | 0.35 | 1a | 1.45 | DQ6 |
| #17 | 0.36 | 0.59 | 1a | 1.53 | DQ6 |
| #19 | 1.21 | 0.92 | NEG | 2.32 | NA |
| #23 | 3.69 | 2 | NEG | 1.27 | DQ4 |
| #24 | 1.2 | 1.2 | AMR/FSGS | 4.32 | DQ2 |
| #29 | 1.96 | 1.8 | NEG | 3.48 | NA |
| #37 | 3.26 | 2.2 | 1B | 1.8 | NA |
| #43 | 1.84 | 1.6 | NEG | 2.42 | NA |
AUC ROC and Rejection threshold of !%