AML MRD testing with flow cytometry

MRD means measurable residual disease. The test is more sensitive than simply viewing cells under a microscope, but it is one part of response assessment and does not make a treatment decision by itself.

The laboratory passes cells individually through a laser and records patterns of markers on and within them. Specialists compare these patterns with those expected in healthy developing blood cells and with the abnormal pattern identified in the leukaemia.

A detected result means cells with a concerning pattern were found in the tested sample. A not-detected result means the laboratory did not identify such cells above its reporting limit; it cannot exclude every remaining leukaemia cell. Sample quality and timing affect interpretation.

MRD flow cytometry usually uses bone marrow because AML develops there, although blood may be informative in selected circumstances. Before sampling, tell the team about blood-thinning medicines, bleeding problems, allergies and previous difficulty with marrow procedures.

Review the report with the haematology team rather than comparing a single word across laboratories. Ask whether the sample was adequate, what method and reporting limit were used, how the finding compares with earlier samples, and whether molecular testing adds useful information.

After a bone marrow sample, contact the procedure team for increasing redness, swelling, discharge, persistent bleeding or worsening pain at the site. Follow the dressing and activity advice supplied by the clinic.

During or after AML treatment, fever, shaking chills, uncontrolled bleeding, severe breathlessness, chest pain, confusion or sudden deterioration require urgent medical attention according to your haematology service's emergency instructions. Do not wait for an MRD appointment to report these problems.

Useful questions include: At what treatment point was this sample taken? Was MRD detected, and how certain is the classification? Was the specimen good enough to assess? Does the result change my current plan? When will testing be repeated, and will the same technique be used?