MRD
Also written as: MRD — Minimal Residual Disease
Minimal residual disease. The small number of leukemic cells that may remain after treatment and are undetectable by conventional methods.
Full Definition
Minimal residual disease (MRD) refers to the presence of small numbers of malignant cells that persist after treatment but are below the detection threshold of conventional morphologic examination. In pediatric acute leukemia, MRD is typically measured by flow cytometry or PCR-based methods and can detect one leukemic cell among 10,000 to 100,000 normal cells. MRD levels at specific time points during treatment are powerful prognostic indicators and increasingly used to guide therapy intensity. Positive MRD often indicates the need for more intensive treatment, while negative MRD suggests good treatment response and favorable outcome. Modern pediatric leukemia protocols incorporate MRD-based risk stratification.
Usage
Usage note: Always spell out as 'minimal residual disease' on first use, then abbreviate as MRD.
In Context
- "Flow cytometric MRD was negative at the end of induction therapy." — laboratory report
- "The patient was reclassified as high-risk based on positive day 15 MRD." — treatment stratification