Prognostic significance of peripheral monocytic myeloid-derived suppressor cells and monocytes in patients newly diagnosed with diffuse large b-cell lymphoma.

OBJECTIVE The revised International Prognostic Index (R-IPI) aids in predicting the prognosis of patients with diffuse large B cell lymphoma (DLBCL), but R-IPI yields no significant differences in assessing different subtypes of DLBCL. It is necessary to identify patients with a high-risk of DLBCL and alternative therapy should be delivered as early as possible. METHODS In total, 144 patients newly diagnosed with DLBCL including 63 GCB-DLBCL and 81 non-GCB-DLBCL and 30 healthy controls were enrolled. Peripheral monocytic myeloid-derived suppressor cells (M-MDSC) (CD14(+)HLA(-)DR(low/-)) were detected by flow cytometry and the percentage of monocytes (MΦ) was evaluated by completed blood count (CBC). The correlation between M-MDSC% and MΦ% was statistically analyzed. RESULTS Compared with healthy controls, significant increase was observed in M-MDSC% and MΦ% in DLBCL patients (both P<0.001). Significant difference of M-MDSC% was found between GCB-DLBCL and non-GCB-DLBCL patients in both poor (P<0.001) and very good groups (P=0.03), whereas no statistical significance in the good group (P>0.05). The MΦ% in non-GCB-DLBCL patients was significantly higher than that in GCB-DLBCL counterparts merely in the poor group (P<0.001). Positive correlation was noted between MΦ% and M-MDSC in all DLBCL patients rather than in healthy controls (r=0.227 P=0.229). CONCLUSION The percentage of peripheral MΦ was positively correlated with M-MDSC% in patients with different subtypes and risks of DLBCL. Peripheral MΦ% and M-MDSC% combined with R-IPI score may be useful for predicting the prognosis of patients newly-diagnosed with DLBCL.