Clinical application of quantitative detection of plasma DNA in evaluating the effect of chemotherapy on chronic leukemia / 医学研究生学报

ABSTRACT

Objective Plasma circulating DNA can be em-ployed in place of bone marrow examination for the auxiliary diagnosis of leukemia.This study aimed to explore the clinical application of the plasma DNA level in evaluating the effect of chemotherapy on chronic leukemia. Methods We collected blood samples from 52 patients with chronic myelogenous leukemia (CML) (33 in the chronic phase, 7 in the acceleration phase, and 12 in the blast phase) , 85 with chron-ic lymphocytic leukemia (CLL) (28 with complete remission, 27 with partial remission, and 30 with no remission), 4 patients with hairy cell leukemia (HCL), and 80 healthy subjects.We simultaneously obtained plasma DNA and recombinant plasmid DNA using the BI-LATEST DNA Kit and examined the human β-actin gene and the level of plasmid DNA by real-time quantitative PCR. Results Before chemotherapy, the median value of plasma DNA was 149.46(30.63-496.91)ng/ml in the CML and 101.54(69.10-258.14) ng/ml in the CLL patients, both significantly higher than in the healthy controls (19.05[12.67-25.92]ng/ml) (P<0.01).After chemotherapy, the plasma DNA level of the CML patients was remarkably decreased, but still higher than that of the controls ( P<0.01).The CML patients in the chronic phase showed a markedly higher level of plasma DNA (302.89[93.33-541.52]ng/ml) than those in the blast phase (43.19[23.54-70.03]ng/ml) and acceleration phase (28.11[16.21-92.07]ng/ml) (P<0.05).The CLL patients with CR exhibited a significantly lower level of plasma DNA (24.29[14.64-30.74]ng/ml) than those with PR (106.88 [96.23-143.25]ng/ml) and NR (460.73[284.57-653.38〗ng/ml) (P<0.01), but all dramatically higher than that of the healthy controls (P<0.01) Conclusion The quantification of plasma DNA has a clinical application value in evaluating the effect of chemo-therapy on chronic leukemia.