Abstract: Objective:To explore the differences of the relative expression levels of plasma long chain non encoding RNA (lncRNA) MALAT1, LincRNA-p21 and GAS5 in the patients with multiple myeloma (MM) and chronic lymphocytic leukemia (CLL), and to clarify their significances in the differential diagnosis of MM and CLL. Methods: A total of 60 cases of MM patients (MM group), 60 cases of CLL patients (CLL roup) and 60 healthy persons after physical examinations (control group) were selected as the subjects. The plasma levels of lncRNA MALAT, LincRNA-p21 and GAS5 of the subjects in three groups were detected and compared. Results: The relative expression levels of lncRNA MALAT1 and GAS5 in plasma of the patients in MM group were significantly higher than those in the other two groups(P<0.05);the relative expression level of LincRNA-p21 in plasma of the patients in CLL group was significantly lower than those in the other two groups(P<0.05).The area under receiver operating characteristic curve(ROC)(AUC) of plasma LincRNA-p21 in the diagnosis of CLL was 0.850, its 95% confidence interval (CI) was 0.780-0.921. The AUC of plasma lncRNA MALAT1 and GAS5 in the diagnosis of MM were 0.898 and 0.815; their 95% CI were 0.836-0.959 and 0.740-0.890, respectively. The AUC of plasma lncRNA MALAT1, LincRNA-p21 and GAS5 in the differential diagnosis of CLL and MM were 0.878, 0.778 and 0.805, and their 95%CI were 0.814-0.942, 0.691-0.865 and 0.727-0.882, respectively. Conclusion: The incidence of MM is related with the high expressions of lncRNA MALAT1 and GAS5 in plasma and the incidence of CLL is related with the low expression of LincRNA-p21 in plasma. The relative expression levels of the above lncRNA can be used as the auxiliary indexes in the diagnosis of MM and CLL.

Key words: chronic lymphocytic leukemia, plasma, long chain non encoding RNA, multiple myeloma