Highly Sensitive Detection of Donor Chimerism by Next-Generation Sequencing

Abstract

Donor chimerism analysis is used for monitoring engraftment status and risk of disease relapse following allogeneic stem cell transplantation. Recently developed assays using next-generation sequencing have demonstrated enhanced sensitivity and accuracy compared with standard capillary electrophoresis methods. This work presents validation results using One Lambda Devyser Chimerism assay, a next-generation sequencing-based test for monitoring donor chimerism. A total of 270 samples, including clinical and cell-line DNA, were tested. There was a high correlation between chimerism results obtained with One Lambda Devyser and short tandem repeat assays (R² = 0.998). Determination of the limit of blank, limit of detection, and limit of quantitation indicated that One Lambda Devyser Chimerism assay can reliably detect recipient DNA fractions as low as 0.1%. Analytical specificity was >99.9%. Reproducibility, linearity, DNA library characteristics, and sequencing metrics are presented. The suitability of DNA markers was verified in a population predominantly African American and Hispanic, comprising 30 recipient/donor pairs. The average number of informative markers per pair was seven, with a lower representation (five markers) in related pairs. In conclusion, the results show that One Lambda Devyser Chimerism assay is a highly sensitive test for detecting donor chimerism in a diverse patient population. The assay performed remarkably well at low recipient concentrations, having the potential to detect early changes associated with disease relapse.