The assessment of minimal residual disease (MRD) during first-line therapy is regarded as most important prognostic factor in adult and childhood acute lymphoblastic leukemia (ALL). However, current methods used for MRD assessment have major drawbacks. Multiparameter flow cytometry is not fully standardized and requires expert skills. Allele specific PCR of clonal immunoglobuline (IG) and T-cell receptor (TR) gene rearrangements is time consuming and needs patient-specific reagents, thus making it ineligible for IVD-guided analytical validation. In this context amplicon based IG/TR NGS was introduced, which allows for the characterization of millions of IG/TR rearrangements in parallel without the need for patient specific reagents, thus allowing IVD-guided analytical validation. The downside of this method is that it is prone to amplification biases that hamper correct quantification. Also, contamination of libraries leading to false positive results constitutes a severe problem in diagnostic routine. The goal and hypothesis of Quant-ALL is to eliminate these disadvantages by a combination of innovative high throughput molecular tools.
Aims and methods: (1) Establishment of an amplicon based IG/TR NGS approach using single DNA copy barcoding and droplet microfluidics for IG/TR based MRD quantification in ALL. (2) Optimization of existing bioinformatics tools used for IG/TR NGS to quantify index IG/TR sequences. (3) Transfer of this technology to a pre-existing centrifugal microfluidic platform for full automation and standardization. (4) Validation of technology for childhood and adult ALL using biobanked follow-up samples that are MRD quantified with standard technologies.
Expected results are the full automation of a high throughput technology for MRD quantification in ALL. This technology will be standardized and validated to allow a wide distribution to ALL MRD reference laboratories and fundamentally improve MRD quantification in childhood and adult ALL.