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Integrating Donor Derived Cell-Free DNA Fraction and Absolute Quantification for Enhanced Rejection Diagnosis in
Weijian Nie1, Yan Wang2, Qian Fu1
1Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
Insights
Combining donor-derived cell-free DNA (dd-cfDNA) fraction and absolute quantification significantly improves kidney transplant rejection detection. These methods, particularly the double-positive and double-negative approaches, offer high accuracy for monitoring transplant recipients.
Area of Science:
- Nephrology
- Transplant Immunology
- Molecular Diagnostics
Background:
- Kidney transplant rejection remains a significant clinical challenge.
- Accurate and non-invasive diagnostic tools are crucial for timely intervention.
- Donor-derived cell-free DNA (dd-cfDNA) shows promise as a biomarker.
Purpose of the Study:
- To evaluate the diagnostic accuracy of combining dd-cfDNA fraction and absolute quantification for kidney allograft rejection.
- To assess the performance of double-positive and double-negative diagnostic strategies.
Main Methods:
- Prospective study including 50 kidney transplant recipients undergoing biopsy.
- Measurement of dd-cfDNA fraction and absolute concentrations.
- Receiver operating characteristic (ROC) analysis and application of double-positive/negative methods.
Main Results:
- dd-cfDNA fraction cutoff (1.08%) showed high sensitivity (93.33%) and specificity (91.43%).
- Absolute dd-cfDNA threshold (32 cp/mL) demonstrated moderate diagnostic performance.
- Double-positive and double-negative methods exhibited superior accuracy, with the latter achieving 100% sensitivity and NPV.
Conclusions:
- Combining dd-cfDNA fraction and absolute quantification enhances diagnostic accuracy for kidney transplant rejection, particularly antibody-mediated rejection (ABMR).
- The double-positive and double-negative approaches offer high predictive value.
- These combined methods hold significant clinical potential for monitoring kidney transplant recipients.
Abstract:
Background: This study aimed to assess the diagnostic accuracy of combining donor-derived cell-free DNA (dd-cfDNA) fraction and absolute quantification in detecting kidney allograft rejection. Methods: A prospective study was conducted from December 2019 to April 2021 at the First Affiliated Hospital of Sun Yat-sen University. Kidney transplant recipients who underwent biopsy, including cases of T-cell-mediated rejection (TCMR), antibody-mediated rejection (ABMR), and borderline rejection, were included. dd-cfDNA fraction and absolute concentrations were measured, and diagnostic efficacy was evaluated using receiver operating characteristic (ROC) analysis. The double-positive and double-negative methods were applied to assess performance. Results: A total of 50 kidney transplant recipients were included. The dd-cfDNA fraction cutoff of 1.08% achieved 93.33% sensitivity and 91.43% specificity (AUC = 0.95), with an NPV of 96.97% and a PPV of 82.35%. The absolute dd-cfDNA threshold of 32 cp/mL yielded 80.00% sensitivity and 71.43% specificity (AUC = 0.78), with an NPV of 89.29% and a PPV of 54.55%. The double-positive method provided superior accuracy, with a PPV of 91.67% and an NPV of 89.47%, demonstrating 73.33% sensitivity and 97.14% specificity. The double-negative method achieved 100% NPV and 100% sensitivity. Conclusions: Combining dd-cfDNA fraction and absolute quantification improves diagnostic accuracy for kidney transplant rejection, especially ABMR. The double-positive and double-negative approaches show high predictive value, offering potential clinical value for monitoring kidney transplant recipients.
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