Minimal/measurable residual disease (MRD) testing is a well-established predictor of outcome following treatment in almost all hematologic malignancies. It has become an established surrogate endpoint in clinical trials for new compounds in chronic lymphoid leukaemia and chronic myeloid leukaemia, as well as being increasingly used to manage standard patient care.
Lymphoid malignancies lack a pathognomic genetic marker consistent for all patients such as the BCR::ABL1 rearrangement in CML. Instead, the immunoglobulin genes offer an ideal target as each neoplastic lymphoid cell harbours identically rearranged heavy, light, and kappa or lambda genes. Detection of patient specific IG/TCR gene rearrangements by allele specific oligonucleotide (ASO) PCR has a limit of detection (LoD) of 10-5 and is widely adopted and well standardised.
Next generation sequencing (NGS) based approaches have been developed to identify and quantify immunoglobulin VDJ rearrangements. This a highly sensitive method – an LoD of 6.8x10-7 normal cells has been reported, requiring fewer cells and without the limited sample processing window as seen for multi-parameter flow cytometry (MPFC). Furthermore, it is applicable to 90% of patients.
Whilst external quality assessment/proficiency testing (EQA/PT) has been established for MPFC and ASO-PCR for IG/TCR, it has not been established for NGS approaches for IG/TCR. This new programme will assess laboratories’ ability to identify and quantify rearranged IgH, IgK and IgL in a measurable residual disease setting, as used to monitor changes in disease burden post treatment.
Each round features a total of 4 samples, one diagnostic DNA sample used to identify a target clonotype and three lyophilised cell based samples; two MRD ‘positive’ samples and an MRD ‘negative’ sample. There will be one round per annum initially.
Registration for this programme will be available when registration opens for 2023-2024 in February 2023.