MRD stands for Minimal Residual Disease. It is a term that simply put means that they detect leukemia cells with a much greater sensitivity than they did in the early days of childhood leukemia treatment. Instead of looking at 100 cells and finding 1 leukemia cell, they can now look at 10,000 cells and find 1 leukemia cell.
MRD came into importance in the treatment of childhood ALL in the 1990s. Since this was the time (1999) that my son was being treated for ALL, I read the scientific papers and then attempted to explain MRD to other parents of childhood ALL. Thus, this section.
In COG trials in the early 2000s, patients were tested for MRD but the results were not shared with the parents if the child was enrolled in double-blind studies. This caused some consternation amongst the parents; it was frustrating to know that what could well be very important information as to the success of the treatment so far was being withheld from them. (And even if they could be told, they could not be sure what the results meant.)
Although written in 1999, the basic information in this MRD section is still pertinent. And today, the results of MRD assays are directing the treatment in the new COG clinical trials for ALL (see the 2005 trials for low- and high-risk ALL for details on when/how this is done). St. Jude's has used MRD to direct treatment for several years. (2005 note.)
- Preface How I came to write this section
- Introduction What is MRD
- Clinical Remission The traditional method of defining remission
- Tests important in the diagnosis of leukemia
- Flow cytometry
- FISH, FISH/MRD
- the concept of clonality
- Southern blots
- PCR, PCR/MRD
- Overviews of Journal Articles on MRD My take on several journal articles published in the 1990s
- Bibliography for this MRD section
- Bibliography of MRD articles published before/since this section was written
External link added 2003: St. Jude's on MRD.
External link added 2011: WikiPedia on MRD.
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