[Quantitation of Circulating Cell-free DNA in Patients with Lymphoma and Its Clinical Significance].

OBJECTIVE: To evaluate the value of circulating cell-free DNA (CFDNA) quantification for screening lymphoma, to analyse the relationship of circulating CFDNA with curative effect under standard therapeutic schedule, and to determine whether circulating CFDNA could be applied to monitor and prognosticate lymphoma.

METHODS: The peripheral blood samples from 32 patients(21 cases of lymphoma and 11 cases of lymphadenitis) with superficial lymph node enlargement were collected, 9 healthy volunteers were as the normal control. Fluorescent quantitative PCR was used to detect the circulating CFDNA in 3 groups. Then, the relationship of circulating CFDNA with common characteristics of lymphoma was analysed, so as to evaluate the importance of circulating CFDNA to the curative effect and prognosis.

RESULTS: The circulating CFDNA level in patients with lymphoma was higher than that in patients with lymphadenitis and healthy volunteers (56.71±50.61) ng/ml vs (19.21±15.52) ng/ml and (8.26±7.06) ng/ml (P<0.05), but the difference between the latter 2 was not statistically significant (P=0.118). The circulating CFDNA level in lymphoma significantly correlated with the level of lactate dehydrogenase(LDH) (P<0.05). ROC analyses revealed that the detection of plasma DNA could discriminate the lymphoma from normal controls with 75% sensitivity, 85% specificity and with a cut-off value of 24.67 ng/ml. The higher circulating CFDNA clearance rate after standard therapy, the higher the rate of complete remission(CR) (P<0.05) and the longer overall survival(P<0.001).

CONCLUSION: Elevated circulating cell-free DNA levels may be useful as a screening tool for lymphoma. Circulating CFDNA level may serve as a potential indicator for evaluation of the curative effect and prognosis.