OBJECTIVETo investigate the change of plasma IL-16 level in patients with multiple myeloma(MM) and its clinical significance.

METHODSSixty-two patients with multiple myeloma were admitted in our hospital from June 2008 to June 2015. Forty healthy volunteers were selected as control group. The peripheral blood of all the patients and healthy volunteers were collected before the treatment of patients. The levels of IL-16, Cys-C, LDH and β2-MG were measured. ROC curve was used to analyze the optimal IL-16 thresholds in MM patients. Kaplan-Meier method was used to analyze the factors affecting overall survival.

RESULTSThe levels of IL-16, Cys-C, LDH and β2-MG in the MM group were significantly higher than those in the control group (P<0.05). The levels of IL-16, Cys-C, LDH and β2-MG in patients with different ISS were significantly different (P<0.05). The levels of IL-16, Cys-C, LDH and β2-MG in ISS III groups were higher than those in ISS I and ISS II groups(P<0.05). When the IL-16 concentration was 171.26 ng/L, the AUC was 0.787 (P<0.01), and the sensitivity and specificity were 82.25% and 75.80%, respectively, when the IL-16 threshold was predicted by ROC curve analysis. The 3-year overall survival rates of patients with IL-16≤171.26 ng/L and IL-16>171.26 ng/L were 91.93% and 51.61%, respectively (P<0.01). Multivariate analysis showed that the changes of IL-16 levels were significantly related with overall survival (P<0.01).

CONCLUSIONThe level of IL-16 in peripheral blood of patients with multiple myeloma has been cofirmed to be significantly elevated, and the elevated IL-16 is closely related with the prognosis.