Measurable (minimal)
residual disease (MRD)

Molecular and immunophenotypic monitoring of disease progress to control risk-adapted treatment.

Testing material
  • Bone marrow
  • Peripheral blood
Processing time

depending on method used

The assessment of MRD has prognostic significance and allows early detection of relapse after treatment failure. It is therefore highly relevant for the selection and control of a risk-adapted therapy. The detection of MRD is usually performed with state-of-the-art analytical techniques from the field of molecular genetics and immunophenotyping, as these allow a high sensitivity.

Sensitivities

Depending on the investigated alteration and used technology, the detection ability of MRD can vary greatly. Due to their high sensitivity - meaning the ability to detect a altered cell within a population of healthy cells - molecular genetics and immunophenotyping are clearly outperforming conventional cytomorphology and cytogenetics for MRD detection.

Method used

Sensitivity

(positive cells/investigated cells)

Sensitivity

Cytomorphology

5-10/100

5-10%

Chromosome analysis (cytogenetics)

1-2/20

5-10%

Fluorescence in situ hybridisation (FISH)

1-5/100

1-5%

Fragment length analysis

2-10/100

2-10%

Next-generation sequencing

1-3/100

1-3%

Multicolor Flow Cytometry (MFC)

1/10,000

0.01%

Digital PCR (dPCR)

1/10,000

0.01%

Quantitative real-time PCR

1/10-100,000

0.01-0.001%

Methodology

Molecular genetic determination of MRD

The molecular genetic determination of MRD is based on the detection of leukemia-specific DNA sequence variants, chromosomal translocations and genomic rearrangements. Using molecular biology testing methods, patient-specific mutations can be identified at diagnosis and followed during the course of disease and treatment.

The molecular genetic detection of MRD is based on the functional principle of the polymerase chain reaction (PCR). This is an enzyme-based method for the specific amplification of nucleic acid sequences. Analytical methods used in routine molecular genetic MRD diagnostics include: Next-generation Sequencing (NGS) using ultra-deep amplicon sequencing, digital PCR (dPCR), quantitative real-time PCR (qPCR), and fragment length analysis.

An example of this is shown by patients with chronic myeloid leukemia (CML), where molecular genetic MRD diagnostics play a central role in guiding therapy. More than 95% of all CML patients have a reciprocal chromosome translocation at diagnosis, which leads to a BCR-ABL1 fusion gene. Quantification of the BCR-ABL1 fusion transcript by sequence-specific qPCR is suitable for highly sensitive determination of MRD burden. An increase in the mutational load of the BCR-ABL1 fusion transcript in CML patients in complete molecular remission may indicate treatment failure.

Other mutations for MRD assessment based on current diagnostic guidelines (Schuurhuis et al., 2018, Döhner et al., 2017) and routinely detected in acute leukemias are as follows:

  • AML with inv(16)/CBFB-MYH11

  • AML with t(8;21)/RUNX1-RUNX1T1

  • AML with t(9;11)/KMT2A-MLLT3

  • AML with t(6;9)/DEK-NUP214

  • Philadelphia-positive ALL or AML with t(9;22)/BCR-ABL1

  • AML with mutations in the NPM1 gene

For a complete list of all markers we offer, please refer to the additional section Molecular Genetics of the request form.


MRD using immunophenotyping

Leukemia-associated aberrant immunophenotypes (LAIPs) that do not – or very rarely – occur in this constellation on the cells of normal bone marrow can be detected in cases of acute leukemia. They are divided into:

  • Cross-lineage expression of lymphatic markers for AML (e.g. CD19-positive AML), i.e. myeloid markers for ALL (e.g. CD33-positive ALL)

  • Asynchronous antigen expression (simultaneous expression of immature markers with mature markers, e.g. CD34- and DD11b-positive AML)

  • Absent antigen expression (e.g. HLA-DR-negative AML)

  • Antigen overexpression (e.g. CD33++CD34++ AML).

Of central importance is the correct identification of an LAIP, so precise knowledge of – and benchmarking with – the immunophenotype in the normal bone marrow is essential for MRD quantification. The LAIP is often characterized by the expression intensity of a particular antigen, which can vary significantly from case to case. It is therefore necessary to define one or several LAIPs for each patient individually. Hence, individual identification of the LAIP at the time of diagnosis is a precondition to enable MRD testing. The use of an extensive panel of antibodies is necessary for detection of an LAIP, especially for AML, in order to identify rare LAIPs and to make them available for downstream progress examinations.

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Request form

Please enclose this completed examination form with your sample shipment. The form represents all diagnostic methods and analyses completely.

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Request form hemoglobinopathy

Order for laboratory and molecular genetic testing for hemoglobinopathies.

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Patient consent - Research projects

By providing this patient consent, you agree to the use of excess biomaterial for research purposes.

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Primary sample collection manual

Detailed information on test material and shipment can be found in our primary sample collection manual.

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Information for correct sampling of buccal swap and nail material

Here you will find information on the correct sampling of germline material.

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Your contact person

»We achieve higher quality through interdisciplinarity.«

Prof. Dr. med. Wolfgang Kern

Executive Management
Internist, Hematologist and Oncologist
Deputy Head of Immunophenotyping

T: +49 89 99017-200