[Detection of minimal residual disease in children leukemia patients by using PCR - review].

MRD detection in children leukemia has a potential importance to predict clinical outcome and to modify treatment protocols of the diseases. Although some patients with leukemia have achieved complete remission according to the clinical and morphological criteria, there are still very low numbers of malignant cells that can not be discriminated by morphology and remained in bone marrow, which is called minimal residual disease (MRD) and is the main reason leading to relapse. MRD detection has an important significance for designing treatment protocols. Several methods of MRD detection have been developed. These include conventional cytogenetics, fluorescence in situ hybridization (FISH), flow-cytometric immunophenotyping (FCM), Southern blot and polymerase chain reaction (PCR) techniques, etc. Each of these techniques has its advantages and disadvantages, so not all of them are suitable for clinical MRD detection because of several inherent disadvantages, such as limited sensitivity, time-consuming, high cost, or requiring high-quality DNA or RNA. For example, the sensitivities of conventional cytogenetics, FISH, FCM and Southern blot approaches for MRD monitoring are 10(-1) - 10(-2), 10(-2), 10(-3) - 10(-4) and 10(-1), respectively. Relatively, PCR can reach a good sensitivity of 10(-4) - 10(-6), and show more advantages, such as fast, specific, simple and low-cost, as well as minimal amounts of DNA or RNA for detection, etc., so PCR has its specific features for MRD detection. In this review, the progress on the detection technique for screening leukemia specific marker by muitiplex PCR and FQ-PCR in recent years are summarized.