ABSTRACT
Objective@#To investigate the clinical significance of tumor associated macrophages (TAM) in multiple myeloma (MM) and the relationship with angiogenesis and immunosuppression.@*Methods@#Seventy cases of MM patients diagnosed from August 2015 to June 2017 were enrolled in the study as experimental group, 20 cases of benign hematological diseases (13 with iron deficiency anemia and 7 with megaloblastic anemia) patients as control group. Immunohistochemical method was used to detect the expression of CD163, CD34 and VEGF in bone marrow samples, and flow cytometry was used to detect the proportion of regulatory T cell (Treg cells), ELISA was used to detect the level of IL-10, and the clinical features were analyzed.@*Results@#①Among the 70 patients, there were 31 males and 39 females with a median age of 65 (50~78) years old. TAM infiltration density, microvascular density (MVD), VEGF expression level, Treg ratio and IL-10 level in bone marrow samples of 70 MM patients were significantly higher than those of benign hematological diseases (P<0.05). ②In the MM group, the above indexes of the patients with disease stabilized (15 cases) were lower than those of the newly diagnosed group (35 cases) and the relapse refractory group (20 cases) (P<0.05), those of relapse refractory group were higher than those of newly diagnosed group (P>0.05). ③Of the 35 newly diagnosed MM patients, 27 completed 4 courses of treatment. In the effective group (15 cases), the TAM infiltration density after treatment was significantly lower than that before treatment, the difference was statistically significant[(20.20±7.66) vs (28.87±11.97), t=2.362, P=0.025]; while in the ineffective group of 12 cases, the difference of the TAM infiltration density before and after treatment was not statistically significant[(42.00±13.76) vs (48.25±13.59), t=1.119, P=0.275]. ④TAM infiltration density in the effective group after bortezomib treatment (21 cases) were lower than those in the non-bortezomib treatment group (18 cases)[(16.52 ±4.26) vs (19.27 ±5.82), t=1.662, P=0.170]. ⑤The TAM infiltration density in MM patients was positively correlated with MVD, VEGF expression level, Treg cell ratio and IL-10 level (P<0.001).@*Conclusion@#The infiltration of TAM in the microenvironment of MM, which may promoting angiogenesis and inhibiting immune response, is related to the occurrence, development, therapeutic effect and drug resistance of MM.