Quantitative Detection and Integrality Analysis of Plasma Circulating Cell-Free DNA in Multiple Myeloma
Objective:To investigate the role of plasma circulating cell-free DNA(cf-DNA)in the screening and diagnosis of patients with newly diagnosed multiple myeloma(MM)and explore the changes of cf-DNA in terms of content and integrality in the assessment of disease in patients treated with chemotherapy.Methods:Peripheral blood specimens were collected from 35 newly diagnosed MM patients and 18 healthy volunteers,and 13 of the 35 patients who had finished 3 courses of standard induction chemotherapy were selected as follow-up group.The ALU247 and ALU115 fragments were used as the target genes,and the cf-DNA content in the plasma of patients and healthy controls was measured by quantitative polymerase chain reaction(qPCR).The integrality of cf-DNA was calculated by the ratio of ALU247 to ALU115.Results:Both the concentration of ALU247 and ALU115 fragments and the integrality of cf-DNA in patients were significantly higher than those in healthy controls(all P<0.05).Patients who had underwent 3 courses of induction chemotherapy had significantly decreased concentration of ALU247 and ALU115 fragments and integrality of cf-DNA after treatment(all P<0.05),and strong positive correlations were manifested between cf-DNA integrality and serum M protein content,as well as proportion of abnormal plasma cells in bone marrow before and after treatment(r=0.703,0.705).Conclusions:Cf-DNA has certain positive significance for the screening and diagnosis of MM.Furthermore,cf-DNA may be a synergism or alternative to serum M-protein content and proportion of abnormal plasma cells in bone marrow in assessing the condition,curative effect and prognosis of patients.