Evaluation of Chimerism Testing by Next-Generation Sequencing Using Insertion/Deletion Markers: Analytical Validation...

Area of Science:

• Hematopoietic stem cell transplantation
• Molecular diagnostics
• Genetics

Background:

• Post-transplant engraftment monitoring is crucial for managing allogeneic hematopoietic transplantation.
• Chimerism analysis, typically using short tandem repeats (STR), assesses donor cell presence.
• Next-generation sequencing (NGS) enables analysis of new genetic markers like single nucleotide polymorphisms (SNPs) and insertions/deletions (indels).

Purpose of the Study:

• To evaluate the performance characteristics (accuracy, sensitivity, reproducibility) of the GenDx NGStrack assay.
• To compare the NGStrack assay with traditional STR-based methods for chimerism analysis.
• To demonstrate the clinical utility of the NGStrack assay in post-transplant patient management.

Main Methods:

• Performance evaluation of the NGStrack assay for detecting donor and recipient DNA percentages (0.5%–99.5%).
• Comparative analysis of NGStrack assay results against a STR-based chimerism analysis method.
• Clinical case studies illustrating the assay's application on various cell subsets.

Main Results:

• The NGStrack assay demonstrated high accuracy, sensitivity, and reproducibility.
• Chimerism analysis using indel markers via NGS achieved a sensitivity of 0.5%, significantly higher than STR-based methods (1-5%).
• The assay accurately correlated chimerism levels with clinical events, including disease relapse and graft failure.

Conclusions:

• The NGStrack assay offers superior sensitivity for chimerism analysis compared to STR methods.
• This increased sensitivity facilitates earlier diagnosis of complications like disease relapse and graft failure.
• The assay supports more precise clinical management and improved patient outcomes following transplantation.